Upper Grades Math & Science Support
M. Mackenzie - Harbor View Elementary - NMUSD - CA
Be a Viking, explore your universe with respect and an open mind.
STANDARDS
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Upper Grades Math & Science Support Be a Viking, explore your universe with respect and an open mind. |
STANDARDS |
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Grade 4 |
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Grade 5 |
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Grade 6 |
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Students in grade three are introduced to some of the most fundamental patterns in nature and should be taught that science makes the world understandable. For example, by observing that the stars appear fixed in relation to one another, one can identify five planets in motion against the starry back-ground. Students in grade three begin to build a foundation for understanding the structure of matter and forces of interaction. They will study the properties of light and gain an appreciation for how light affects the perception of direction, shadow, and color. Students in grade three will also extend their knowledge of ecology by learning about different environments, such as oceans, deserts, tundra, forests, grasslands, and wetlands, and the types of organisms adapted to live in each. The curriculum and instruction offered in grade three enable students to read materials independently with literal and inferential comprehension and to support answers to questions about the material by drawing on background knowledge and details from the text. Instruction in information literacy that incorporates library resources will help students become skilled in locating information in texts by using titles, tables of contents, chapter headings, glossaries, and indexes. The science standards complement the mathematics standards by asking students to predict future events on the basis of observed patterns and not by random guessing. Students in grade four will learn to design and build simple electrical circuits and experiment with components such as wires, batteries, and bulbs. They will learn how to make a simple electromagnet and how electromagnets work in simple devices. They will observe that electrically charged objects may either attract or repel one another and that electrical energy can be converted into heat, light, and motion. Students in grade four expand their knowledge of food chains and food webs to include not only the producers and consumers they have previously discussed but also the decomposers of plant and animal remains, such as in-sects, fungi, and bacteria. They will also learn about other ecological relationships, such as animals using plants for shelter or nesting and plants using animals for pollination and seed dispersal. Students in grade four study rocks, minerals, and the processes of erosion. They also study the processes of weathering and erosion as a way of leading into the study of the formation of sedimentary rocks. Students in grade four learn to formulate and justify predictions based on cause-and-effect relationships, differentiate observation from inference, and con-duct multiple trials to test their predictions. In collecting data during investigative activities, they learn to follow a written set of instructions and continue to build their skills in expressing measurements in metric system units. They will analyze problems by identifying relationships, distinguishing relevant from irrelevant information, sequencing and prioritizing information, and observing patterns, all of which support the Mathematics Content Standards.2 They should conduct scientific investigations and communicate their findings in writing. Students in grade five will learn about chemical reactions and discover the special (and shared) properties of metallic elements. They will clearly distinguish between molecules and atoms and chemical compounds and mixtures and learn about the organization of atoms on the periodic table of the elements. They can then be shown how particular chemical reactions (e.g., photosynthesis and respiration) drive the physiological processes of living cells. They will add to what they have learned in previous grade levels about the external characteristics and adaptations of plants and animals and learn about some of the fundamental principles of physiology. They will learn about blood circulation and respiration in humans; digestion of food and collection and excretion of wastes in animals; the movement of water and minerals from the roots of plants to the leaves; and the transport of sugar generated during photosynthesis from the leaves to the other parts of the plant. Students in grade five also study the hydrologic cycle (water cycle), the process by which water moves between the land and the oceans. They will learn how the hydrologic cycle influences the distribution of weather-related precipitation and, as a consequence, the types and rates of erosion. They will also study the solar system and learn that it contains asteroids and comets in addition to the Sun, nine planets, and moons. They will learn the composition of the Sun and the relationship be- tween gravity and planetary orbits. The Science Content Standards and English–Language Arts Content Standards are complementary so that the writing strategies will lay a foundation for good writing on science reports and informative oral science presentations.3 The Science Content Standards and the Mathematics Content Standards also reinforce each other as students analyze, strategize, and solve problems, finding solutions to apply to new circumstances. Students in grade five will also develop testable questions and learn to plan their own investigations, selecting appropriate tools to make quantitative observations. The science curriculum in grade six emphasizes the study of earth sciences. Students at this age are increasing their awareness of the environment and are ready to learn more. The standards in grade six present many of the foundations of geology and geophysics, including plate tectonics and earth structure, topography, and energy. The material is linked to resource management and ecology, building on what students have learned in previous grades. Unless students take a high school earth science class, what they learn in grade six will be their foundation for earth science literacy. Now is an exciting time for the study of life sciences. Knowledge of biological systems is expanding rapidly, and the development of new technologies has led to major advances in medicine, agriculture, and environmental management. A foundation in modern biological sciences, with an emphasis on molecular biology, is essential for students who will become public school science teachers, college and university science professors and researchers, and specialists in technological fields. |
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STANDARD SET 1. Physical Sciences (4 th) Students entering grade four have already had some expo-sure to the subjects of electricity and magnetism, but these standards are a systematic effort to develop the principles of each and show how they are interrelated. The standards in grade four provide a simple understanding of electricity and magnetism and some applications in everyday life; they help to develop a foundation for further learning in high school. 1. Electricity and magnetism are related effects that have many useful applications in everyday life. As a basis for understanding this concept: 1.a . Students know how to design and build simple series and parallel circuits by using components such as wires, batteries, and bulbs. Students should design and build series and parallel circuits with wires, batteries, and bulbs. In series circuits one wire loop connects all the components, so current flows sequentially through the components in the one loop. In parallel circuits several loops of wires connect the components. A simple series circuit consists of two or three light bulbs wired together with a battery in a single loop. If the filament of one bulb breaks (or one bulb is removed from its socket), the single-circuit loop is broken and all the lights go out. Teachers may make a parallel circuit by extending two wires, parallel to each other, from the poles of a battery. Then they connect two or three bulbs, individually, across the parallel wires. If one of the bulb filaments is broken, the other bulbs still remain lit. The series circuit is like a circular road that has no intersection; a series circuit has only a single path, and all components must carry the same current. The amount of current that can flow through a circuit depends on resistance. The lower the circuit’s resistance, the higher the current that can flow through it. Overall resistance in a series circuit is the sum of the resistances of its individual components. In parallel circuits there are intersections and alternate pathways for the current, and each pathway may have different components on it. These alternate pathways split the current between them, depending on their electrical resistance (again, lower resistance along a pathway allows higher current). An alternate pathway with extremely low resistance, such as a wire with no components on it, is sometimes called a short circuit. Short circuits can prevent the rest of the circuit from operating properly and be dangerous because the short-circuiting wire may become very hot.
STANDARD SET 2. Life Sciences (4 th) Students in grade four have already learned about types of plants and animals that inhabit different biomes and will have a simple understanding of adaptation from studies in grades one and three. The standards in grade four help to refine students’ understanding of ecological principles and prepare them to learn much more about the subject in grade six. 2. All organisms need energy and matter to live and grow. As a basis for understanding this concept: 2. a. Students know plants are the primary source of matter and energy entering most food chains. A food chain is a representation of the orderly flow of matter and energy from organism to organism by consumption. Plants harness energy from the sun, herbivores eat plants, and carnivores eat herbivores. Solar energy therefore sustains herbivores and, indirectly, the carnivores that eat them; this is the important principle to be taught.
Students may recall from previous grade levels that animals eat plants or other animals. This standard extends the subject to a greater depth. Food chains and food webs represent the relationships between organisms (i.e., which organisms are consumed by which other organisms). Generally, food chains and food webs must originate with a primary producer, such as a plant that is producing biomass. Herbivores and omnivores eat the plants; carnivores (secondary consumers) in turn eat the herbivores and omnivores. Decomposers consume plant and animal waste, a step that returns nutrients to the soil and begins the process again. Decomposers, such as fungi and bacteria, should be included at each level of the food web as they consume the remains and wastes of plants and animals. 2. c. Students know decomposers, including many fungi, insects, and micro-organisms, recycle matter from dead plants and animals. Plant and animal wastes, including their dead remains, provide food for decomposer organisms such as bacteria, insects, fungi, and earthworms. Decomposers are adept at breaking down and consuming waste materials and therefore complete the food chain, returning nutrients to the soil so that plants may thrive as producers. Bacteria and fungi also pass energy to other parts of a food web. Those microorganisms are themselves consumed by slightly larger organisms, such as worms and small insects, and those small consumers are food for larger animals, such as birds. Microorganisms and their biological ability to decompose matter may be observed in video or film productions using time-lapse photography. Molds grown on bread and fruit may be studied with the use of magnifying lenses; however, it is dangerous for a class to collect wild fungi, culture bacteria, or molds derived from soils or rotting meats. STANDARD SET 3. Life Sciences (4 th) Students have learned in previous grades about the inter-actions of organisms in an ecosystem; this standard set develops the subject still further. The living and nonliving components are clearly distinguished, and the significant effects of invisible microorganisms are also discussed. 3. Living organisms depend on one another and on their environment for survival. As a basis for understanding this concept: 3. a. Students know ecosystems can be characterized by their living and nonliving components. Each ecosystem is characterized by a set of living (biotic) and nonliving ( abiotic) components that distinguish it from other ecosystems. For example, tropical rain forests, coral reefs, and deserts all have distinctly different biotic and abiotic components. This standard challenges students to be systematic in describing the components of an ecosystem and in identifying the characteristics of life 3. b. Students know that in any particular environment, some kinds of plants and animals survive well, some survive less well, and some cannot survive at all. This standard is partly an extension of the study of adaptive characteristics of plants and animals that students may have encountered in grade three. All living organisms have biological requirements for growth and survival and can live only in environments to which they are well adapted. If an environment changes in a way that is harmful to an organism, the organism may not be able to survive. Adaptation is a genetic process that takes many generations to be perceived, so a single individual cannot “adapt” to a change. For example, the thick, blubbery skin of whales is an evolutionary adaptation to cold water. This adaptation is different from the types of changes that help a single individual survive, such as a change in seasonal diet or coloration, which are properly called accommodations. 3. c. Students know many plants depend on animals for pollination and seed dispersal, and animals depend on plants for food and shelter. The idea of plants and animals being mutually dependent was a topic of discussion in grade one. The concept can now be discussed at a much deeper level be-cause students will have an emerging grasp of ecology and natural history. Many plants depend on bees, birds, and bats to pollinate their flowers. The resulting seeds may be scattered away from the parent plant by becoming entangled in the fur of animals. Other seedpods are moved and stored by animals in seed caches; some are consumed and deposited (still fertile) in animal wastes. The fruits of some plants are attractive food sources for animals. Plants often provide shelter for animals, hiding them from predators. 3. d. Students know that most microorganisms do not cause disease and that many are beneficial. Microorganisms play a vital role in the environment. This standard helps students to look beyond the common misconceptions that bacteria are responsible only for diseases and that microorganisms are responsible only for decomposition. Some bacteria and single-celled organisms called protists are photosynthetic, and their contribution as primary producers of biomass in the ocean far exceeds that of the “visible” plants. Food chains and food webs may be based on bacteria and protists ; therefore, a microscope will help students to observe microorganisms. Growing cultures in the classroom provides students with opportunities to study bacteria and protists. A hay infusion is relatively safe to grow in a classroom. Within a few days students will be able to see numerous types of microorganisms through a microscope. Teachers and students should not culture soils and meat broths as some microorganisms can cause serious illness. STANDARD SET 4. Earth Sciences (Rocks and Minerals) (4 th) Earth sciences standards in grade four are divided into three areas of study: rocks, minerals, and the processes of erosion. The topics extend what students have already learned in grade two and prepare them for a deeper level of understanding in grade six. 4. The properties of rocks and minerals reflect the processes that formed them. As a basis for understanding this concept: 4. a. Students know how to differentiate among igneous, sedimentary, and metamorphic rocks by referring to their properties and methods of formation (the rock cycle). Rocks are usually made from combinations of different minerals and are identified from their composition and texture. Molten magma and lava cool and solidify to form igneous rocks. Metamorphic rocks form when a parent rock of any type is subjected to significant increases in pressure and temperature, short of melting. Sedimentary rock forms when rock is weathered, transported by agents of erosion, deposited as sediment, and then converted back into solid rock—a process called lithification. For classroom discussions it is best to begin with minerals and then progress to rocks. (See the next standard for a discussion of teaching about minerals.) Students learn to sort rock specimens into groups of igneous, sedimentary, and metamorphic rocks. Students should learn to relate descriptions of rock mineral content and properties to the three rock groups. Rocks that are hard but show no layering are likely to be igneous rocks. Often they have interlocking crystalline textures. Rocks that are soft, particularly those with layers, are likely to be sedimentary rocks. They often have “fragmental” textures; they look like broken grains of older rocks cemented back together. Hard rocks that have their minerals lined up or arranged in uneven layers are likely to be metamorphic rocks. This description briefly depicts some of the most common rocks; however, there are many exceptions. Field guides to rocks and minerals may be checked out from the school library-media center and would be helpful to have for reference in the classroom. 4. b. Students know how to identify common rock-forming minerals (including quartz, calcite, feldspar, mica, and hornblende) and ore minerals by using a table of diagnostic properties. Geologists describe and identify minerals according to a set of properties, such as hardness, cleavage, color, and streak. Hardness is determined by the Mohs hardness scale, which refers to materials’ relative ability to scratch other materials or be scratched by them. Most earth sciences books contain tables of diagnostic mineral properties that can be used to assist students with sorting or classifying minerals. The identification process requires matching the observed properties of a sample with those noted on a diagnostic table of properties. This standard focuses on only a few of the most common rock-forming minerals (e.g., quartz, calcite, feldspar, mica, hornblende) as well as some important ores, such as galena (lead) and hematite (iron). The colorful ores of copper may also be added to this list. Other resources, such as field guidebooks, computer programs, approved and pre-selected Internet sources, and resources from the school library, may help students identify mineral samples. STANDARD SET 5. Earth Sciences ( Waves ,Wind,Water, and Ice) (4 th) The processes of weathering and erosion continually form the sediments that form new rocks as a part of the constant recycling of Earth’s crust. Some changes on Earth’s surface take place so slowly that they are hard for students to observe; others occur so rapidly that they may be frightening. Erosion and transportation are processes in which material is transported over short or long distances and may take place at different rates. Movement along faults may be slow or fast. Earth’s surface may be built up slowly or erupt suddenly. Students tend to overemphasize the effectiveness of rapid processes because they are easy to identify, but the slow processes may ultimately have the greatest effect on the shape of Earth’s surface. 5. Waves, wind, water, and ice shape and reshape Earth’s land surface. As a basis for understanding this concept: 5.a . Students know some changes in the earth are due to slow processes, such as erosion, and some changes are due to rapid processes, such as landslides, volcanic eruptions, and earthquakes. Erosion may occur so slowly that careful measurements are necessary to establish that a change is taking place; however, landslides may take place very rapidly. Volcanoes can build with explosive speed and then be quiet for long periods. Breaks in Earth’s crust, called faults, experience slow movement, called creep, and rapid movements that cause earthquakes. 5. b. Students know natural processes, including freezing and thawing and the growth of roots, cause rocks to break down into smaller pieces. Chemical weathering occurs when atmospheric components (e.g., oxygen, car-bon dioxide, and water) interact with Earth’s surface materials and cause them to break apart or dissolve. Purely physical processes, such as alternate freezing and thawing of water, exfoliation, or abrasion, may also contribute to the weathering process. Plants may promote weathering as their roots expand in cracks to break rocks. Weathering results in the formation of soil or sediment. To demonstrate the effects of freezing and thawing, teachers may use plastic bottles. Students can fill a soft plastic bottle with cold water. They make certain that all the air is removed from the bottle before tightly capping it and placing it in a freezer. The expansion of water as it freezes will deform the bottle and possibly even split it. 5. c. Students know moving water erodes landforms, reshaping the land by taking it away from some places and depositing it as pebbles, sand, silt, and mud in other places (weathering, transport, and deposition). Weathering produces pebbles, sand, silt, and mud. Erosion and transportation move the products of weathering from one place to another. As erosion transports the broken and dissolved products of weathering, it alters the shape of landforms. The most important agent of transportation is water. Water flowing in streams is energetic enough to pick up and carry silt, sand, pebbles, mud, or at flood stage even boulders. Flowing water reshapes the land by removing material from one place and depositing it in another. STANDARD SET 6. Investigation and Experimentation (4 th) Students in grade four improve their ability to recognize the difference between evidence and opinion. They learn the difference between observation and the inference of some underlying cause or unseen action. Teachers will need carefully designed investigations and experiments that result in predictable student errors to teach the students the difference between observation and inference. Another important milestone is that students will learn to formulate cause-and-effect relationships and to connect predictions and results. 6. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will : a. Differentiate observation from inference (interpretation) and know scientists’ explanations come partly from what they observe and partly from how they interpret their observations. b. Measure and estimate the weight, length, or volume of objects. c. Formulate and justify predictions based on cause-and-effect relation-ships. d. Conduct multiple trials to test a prediction and draw conclusions about the relationships between predictions and results. e. Construct and interpret graphs from measurements. f. Follow a set of written instructions for a scientific investigation. |
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GRADE 5 Science Content Standards STANDARD SET 1. Physical Sciences (5 th) Students will have some familiarity with the idea of atoms and elements from science studies in grade three. In grade five the introduction to chemical reactions and the concept that atoms combine to form molecules require students to clearly distinguish between molecules and atoms and chemical compounds and mixtures. They will be introduced to the idea that the organization of atoms on the periodic table of the elements is related to similarities and trends in the chemical properties of the elements. 1. Elements and their combinations account for all the varied types of matter in the world. As a basis for understanding this concept: 1.a. Students know that during chemical reactions the atoms in the reactants rearrange to form products with different properties. The properties of a chemical compound are controlled by the way atoms of different elements combine to make the compound. During a chemical reaction between two compounds, none of the original atoms are lost, but the atoms re-arrange themselves into new combinations, resulting in the formation of products with properties that differ from those of the reacting compounds. Simple and safe chemistry experiments are described in fifth-grade science texts, and students can identify reactants and products when observing chemical reactions. 1. b. Students know all matter is made of atoms, which may combine to form molecules. The fact that atoms can combine to form molecules is new information, and students should be given the opportunity to practice the correct use of those terms. The number of different types of atoms is relatively small in comparison with the large number of different types of molecules that may be formed. Simple molecules (such as nitrogen, oxygen, water, carbon dioxide, methane, and propane) can be easily represented by molecular models, and this depiction can enhance students’ understanding of the symbolic representations in text. The idea of combinations of atoms sets the stage for learning about chemical bonds in high school. 1. c. Students know metals have properties in common, such as high electrical and thermal conductivity. Some metals, such as aluminum (Al), iron (Fe), nickel (Ni), copper (Cu), silver (Ag), and gold (Au), are pure elements; others, such as steel and brass, are composed of a combination of elemental metals. Elements are grouped together on the periodic table of the elements according to their chemical properties, which in turn are based on the atomic structure of those elements. All pure, elemental metals share some properties in common, such as high electrical and thermal conductivity. Those same properties persist when elemental metals are combined to form alloys (e.g., copper and zinc to make brass). Students may be familiar with many metallic elements (e.g., gold, silver, copper, zinc, aluminum, lead, mercury, chromium) and common metal alloys (e.g., brass, steel, bronze, pewter). It would be helpful for teachers to obtain samples of some of these metals and alloys for their students to study. (Caution: Some heavy metals [such as lead, mercury, and chromium, or their salts] may be hazardous.) In general, metals are shiny, reflecting most of the light that strikes them. They are malleable and ductile (that is, they will bend under pressure and are not brittle). They have a broad range of melting temperatures (e.g., mercury is a liquid at room temperature, gallium will melt in one’s hand, and tungsten has a melting temperature around 3,400 degrees Celsius). The thermal and electrical conductivity of all metals is high compared with nonmetallic substances, such as plastics and ceramics, rocks, and solid salts. Given the appropriate tools, students can develop tests for metals and nonmetals to determine whether they conduct electricity and heat. 1. d. Students know that each element is made of one kind of atom and that the elements are organized in the periodic table by their chemical properties. All matter is made of atoms. The word element refers to those substances that repeated experiments have shown cannot be reduced to still more “elementary” sub-stances. The explanation for this fact is that elements are made of many identical atoms. Water was considered an element at one time. However, it is possible to electrolyze water and produce hydrogen and oxygen gas, both elements. The properties of elements are determined entirely by their atoms. Therefore, elements are said to be made of one kind of atom that accounts for the element’s unique properties. The history of the discovery and name of any one of the elements provides insight into the nature of science and scientific progress. The single most important property of an element is its atomic number. The number may be found on the periodic table along with the symbol and name of the element. Students should know that atomic numbers increase as they read from left to right and move line by line down the periodic table. In grade eight students will be taught that the physical and chemical properties of an element are based on the internal structure of its atoms. The periodic table was originally constructed on the basis of increasing atomic weights of the elements. Those elements were organized in the pattern of a table, much like a monthly calendar, so that elements with similar chemical properties (e.g., metals, halogens, and noble gases) are grouped together in columns. The table gets its name because of the repeating, or periodic, sequences of chemical properties. Students should examine the periodic table of the elements and be able to locate elements by name. They should be able to find common metallic elements on the table and learn to refer to the table as they study and experiment with substances whose names are composites of the elements, such as sodium chloride and carbon dioxide. 1. e. Students know scientists have developed instruments that can create discrete images of atoms and molecules that show that the atoms and molecules often occur in well-ordered arrays. The technique of electron microscopy has opened the door to a new generation of analytical tools that can be used to produce images of individual atoms in a crystalline array. Those images show atoms as “fuzzy balls” aligned in orderly and repeating patterns. From those images it is possible to infer that atoms are discrete objects of finite size and nearly spherical shape. Students may see images in text-books and on the Internet that were obtained by using atomic-resolution instruments, such as electron microscopes and scanning tunneling microscopes. Those images confirm, as hypothesized from years of indirect experimental evidence, that atoms in metals and crystals are arranged in orderly array. The images also show the presence of microfractures in which the order is interrupted, a condition that can affect the strength of the material. 1. f. Students know differences in chemical and physical properties of substances are used to separate mixtures and identify compounds. Students should know the difference between mixtures and compounds. In compounds atomic constituents are separated by chemical rather than by physical means. In addition, every compound has a unique set of chemical and physical properties that can be used to identify it. Compounds and classes of compounds may be identified by chemical reactions with other compounds. An example is the iodine starch reaction. Other chemical reactions in solution may be explored to identify compounds based on changes in acidity, formation of precipitates, and changes in color. In mixtures the atomic constituents are separated by their physical properties. Simple and safe activities may be found in science texts for students in grade five. For example, iron filings can be separated from nonmetallic materials by use of a magnet, and a piece of filter paper can be used to separate suspended particles in a solution. This standard builds on the previous one by challenging students to describe and identify a few common elements and compounds on the basis of observed chemical properties. Students can also study the three common physical states of matter for each of these compounds or elements as well as learn about and compare such properties as solubility in water, boiling and freezing points, sublimation, and reactivity. 1.h. Students know living organisms and most materials are composed of just a few elements. By weight 98.59 percent of Earth’s entire crust consists of eight elements: oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium. Nearly 3,500 known minerals are in Earth’s crust. This fact shows that the complexity of the crust is also the result of a small number of elements in a large variety of combinations. Similarly, living organisms are mostly composed of the elements carbon, oxygen, hydrogen, nitrogen, sulfur, and phosphorus. The number of types of atoms used as “building blocks” is relatively small. The way in which the atoms are organized into molecules provides variety. 1.i. Students know the common properties of salts, such as sodium chloride (NaCl) . Elements and compounds may be described and identified on the basis of observed chemical and physical properties. Salts are compounds typically made from a metal and a nonmetal. Many salts are hard and brittle and have high melting temperatures. Most salts are soluble in water. When dissolved, they become conductors of electricity. Salts are made when strong acids react with strong bases. For example, in the reaction of hydrochloric acid (HCl) with sodium hydroxide (NaOH), hydrogen (H) combines with hydroxide (OH) to form water while sodium (Na) and chlorine (Cl) ions remain in a solution that, if evaporated, would leave the salt sodium chloride (NaCl). Although the use of strong acids and bases in elementary classrooms would present a significant safety risk, science materials adopted for instruction in grade five describe simple experiments that can be safely conducted. There are many different types of salts, but the general use of the term salt refers to sodium chloride, the most common and widely used. In science many salts are (but are not limited to) substances formed by elements in the groups under sodium and magnesium in combination with elements under fluorine. Some salts are poisonous, and students need to be cautioned not to ingest any substances used or produced in an experiment. STANDARD SET 2. Life Sciences (5 th) In grade one students were presented with a simple ex-ample of the relationship between structure and function; namely, that the shapes of teeth are related to the types of materials animals eat. They subsequently learned to identify this phenomenon as an adaptation. Much of the discussion to this point has focused on external characteristics, but plants and animals have internal structures as well that perform vital functions. This subject, which is commonly called physiology, is developed still further in grade seven and in high school. 2. Plants and animals have structures for respiration, digestion, waste disposal, and transport of materials. As a basis for understanding this concept: 2.a Students know many multicellular organisms have specialized structures to support the transport of materials. Multicellular organisms usually have cells deep within them that need to receive a supply of food and oxygen and, in the case of animals, to have cellular wastes re-moved. In higher-order animals blood circulation is responsible for transporting glucose sugar to each cell, providing oxygen, and removing cellular wastes and carbon dioxide. To demonstrate the transport of water in a plant, the teacher may cut the bottom end of a stalk of celery and place it in water containing food coloring. After the colored water is taken up into the plant, students can make cross-sections of the celery and observe them under a microscope. Observing the cross-sections is helpful to students in understanding Standard 2.e. 2. b. Students know how blood circulates through the heart chambers, lungs, and body and how carbon dioxide (CO) and oxygen (O2) are exchanged in the lungs and tissues. Structures of the cardiovascular and circulatory systems, including the heart and lungs, promote the circulation of blood and exchange of gas. The left side of the heart is responsible for pumping blood through arteries to all the tissues of the body and delivering oxygen. Oxygen-poor blood returns to the heart through veins; the right side of the heart is responsible for pumping this blood to the lungs, where the blood eliminates its carbon dioxide and receives a fresh supply of oxygen. Ex-haling expels the carbon dioxide that was transported to the lungs by the blood; inhaling allows the intake of oxygen, which is picked up by the blood. 2. c. Students know the sequential steps of digestion and the roles of teeth and the mouth, esophagus, stomach, small intestine, large intestine, and colon in the function of the digestive system. Digestion starts in the mouth, where chewing breaks down food into smaller pieces that can be easily swallowed and digested. Saliva contains compounds that are also important in breaking down food. The esophagus is a tube that moves food from the mouth to the stomach after swallowing. In the stomach the food is mixed with stomach acids that help to break down the food into parts that can be absorbed. Once food reaches the small intestine, it is neutralized and processed into molecules that can be absorbed into the blood supply. The large intestine recovers water from food, and the colon collects fecal waste (indigestible parts of food) and stores it prior to elimination from the body. 2. d. Students know the role of the kidney in removing cellular waste from blood and converting it into urine, which is stored in the bladder. Cells in living organisms produce waste products that they cannot recycle into other compounds. The focus of this standard is on the systems that remove waste from the cells to prevent it from accumulating and eventually poisoning the organ-ism. Cellular waste products (in the form of molecules) are separated from the bloodstream by the kidneys, stored in the bladder as urine, and removed from the body by urination. In plants many such waste products are stored in a large central vacuole in each plant cell—a kind of garbage dump that is gradually filled as the cell ages. 2. e. Students know how sugar, water, and minerals are transported in a vascular plant. The xylem of plants is a woody tissue responsible for water and mineral trans-port from roots to leaves. Water moving up the plant stem replaces water that has evaporated from the leaves. Plants also transport sugar from the leaves to the roots through a living structure of tubes called the phloem. 2. f. Students know plants use carbon dioxide (CO2) and energy from sunlight to build molecules of sugar and release oxygen Photosynthesis is the name of the process by which plants capture the energy of the sun and use it to initiate a chemical reaction between carbon dioxide and water that results in the production of sugar molecules and the release of oxygen molecules. The chemical process is as follows: energy + carbon dioxide + water react to form sugar + oxygen The process is expressed in the following equation: energy + 6 CO2 + 6 H2O → C6H12O6 + 6 O2 The sugar made during photosynthesis is just an initial compound the plant produces. All the other organic molecules are made by modification of this simple compound. For example, a significant portion of the mass of a log from a tree was once carbon dioxide gas in the air, captured by the leaves of a tree, and fixed into larger organic molecules as shown by the equation noted above. The sugar trans-port processes in the tree are also important in moving the products of photo-synthesis down to the stem, where they could then become a part of the tree. 2. g. Students know plant and animal cells break down sugar to obtain (respiration). energy, a process resulting in carbon dioxide (CO2) and water Cellular respiration is a process of producing energy by the chemical break-down of carbohydrate (sugar) molecules—a process that is the reverse of photo-synthesis. The chemical process is as follows: sugar + oxygen react to form carbon dioxide + water The process is expressed in the following equation: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O Both plants and animals break down sugar to release its energy in a form they can use. This process is called cellular respiration. Carbon dioxide and water are reaction by-products. In animals the carbon dioxide is released into the blood, where it can be transported to the lungs. In the lungs carbon dioxide and oxygen are exchanged (which is the other use of the term respiration) during the act of breathing. It should be noted that cellular respiration is not the same as breathing. STANDARD SET 3. Earth Sciences (Earth’s Water) (5 th) The hydrologic cycle (water cycle) is the process by which water moves between the land and the oceans. Students in grade five learn that cooling in the atmosphere returns water vapor to a liquid or solid state as rain, hail, sleet, or snow. They are also introduced to factors that control clouds, precipitation, and other weather phenomena. 3. Water on Earth moves between the oceans and land through the processes of evaporation and condensation. As a basis for under-standing this concept: 3.a. Students know most of Earth’s water is present as salt water in the oceans, which cover most of Earth’s surface. Because water covers three-fourths of Earth’s surface, this planet is sometimes referred to as the blue planet. Fresh water falls as rain on land and oceans alike. When it falls on land, the water dissolves salts and other mineral matter and carries them to the oceans. When water evaporates from the surface of the ocean, the salts remain behind and accumulate. For this reason the oceans have become salty. Students should know that the amount of fresh water on land is small compared with the amount in the oceans. Using science texts aligned with the Science Content Standards or a variety of library and other resources, students should be able to trace diagrams of the water cycle and understand what they represent. 3. b. Students know when liquid water evaporates, it turns into water vapor in the air and can reappear as a liquid when cooled or as a solid if cooled below the freezing point of water. Liquid water evaporates and becomes invisible vapor when warmed by the sun. Water vapor mixes with the air as it moves through the atmosphere. When the air is cooled, a fraction of the water vapor changes back to liquid water in the form of clouds or rain. If the air temperature becomes low enough, the water will crystallize into a solid state as snow, sleet, or hail. Alternating periods of evaporation and precipitation drive the hydrologic cycle. For a laboratory demonstration a teacher may boil water to produce water vapor and direct the vapor onto the cold outside surface of a beaker filled with ice water. The precipitated water vapor will fog the out-side of the beaker with tiny drops of liquid water. 3. c. Students know water vapor in the air moves from one place to an-other and can form fog or clouds, which are tiny droplets of water or ice, and can fall to Earth as rain, hail, sleet, or snow. Atmospheric circulation moves water vapor, clouds, and fog from one place to another. The tiny droplets or crystals of water that form fog and clouds are so small that they remain suspended in the air. Further cooling of the air can cause these droplets or crystals to grow sufficiently until they fall to the earth as rain, hail, sleet, or snow. By learning basic meteorology from texts and monitoring and plotting local weather data reported by the news media, students can explore the relation-ship between the amount of water vapor in the air (humidity), air temperature, and the likelihood of rainfall or snowfall. 3. d. Students know that the amount of fresh water located in rivers, lakes, underground sources, and glaciers is limited and that its availability can be extended by recycling and decreasing the use of water. Students learn that water quality is affected by various uses and that there are local, state, federal, and global efforts to manage water resources. In California, water resources depend on the use of annual rainwater (and snowpack water) collected in watershed districts, pumping of groundwater, import of water from rivers, and reclamation of water that has been used. Water quality in streams is affected by the disturbance or development of land in a watershed area, runoff of water from farms and city streets, and projects that control the flow of rivers in a flood basin. 3. e. Students know the origin of the water used by their local communities. Students learn the origins of the local water supply through a study of the watershed, creeks, rivers, aqueducts, dams, and reservoirs that serve as its source. Students should know whether their community’s balance between water supply and demand varies seasonally and whether conservation and reclamation techniques are practiced. If water is imported, students should be able to trace it back to its source or sources. STANDARD SET 4. Earth Sciences (Weather) (5 th) Students in grade five learn about the causes of large-scale and small-scale movements in the atmosphere. They apply knowledge of the hydrologic cycle to understanding weather and weather patterns. 4. Energy from the Sun heats Earth unevenly, causing air movements that result in changing weather patterns. As a basis for understanding this concept: 4.a. Students know uneven heating of Earth causes air movements (convection currents). The atmosphere and surface of Earth are heated unevenly, giving rise to both local and global temperature differences. For example, the direct heat absorbed by the surface of the ocean, land, and air may result in different temperatures. Furthermore, the amount of heat varies with latitude, primarily because of the height of the Sun in the sky. The lower the Sun’s elevation, the less direct is its radiation and the less radiation that falls on each square meter of Earth’s surface area. This event is a result of geometry and depends on the angle at which the Sun’s rays intersect Earth’s surface at a locality. When the incoming rays of the Sun intersect Earth’s surface at a more oblique angle, the solar flux is spread out over a wider area. Polar regions are cold because the Sun is low in the sky and its rays fall at very large angles. Closer to the equator, the Sun’s rays fall more directly and the climate is hot. The uneven heating results in local and global temperature differences that create convection currents in the oceans and atmosphere. Students in grade five should know that warm air rises and cold air falls toward Earth’s surface, setting up convection currents in the air that are called winds. Convection is an important mechanism in moving heat around in Earth’s mantle, in the oceans, and in the atmosphere. The process of hot air rising and cold air sinking occurs at Earth’s surface on many different scales, causing local winds and great global air currents, such as the trade winds. 4. b. Students know the influence that the ocean has on the weather and the role that the water cycle plays in weather patterns. Because Earth is a sphere, equatorial regions receive more concentrated sunlight than do polar regions. Temperatures are therefore higher at the equator than farther north or south, but the difference would be much more extreme without the influence of the oceans, which cover about 70 percent of Earth’s surface. Large bodies of water can absorb (or release) a great deal of heat without changing temperature very much; their temperature stays relatively constant from day to night and from season to season. Oceanic circulation carries water warmed near the equator to the north and to the south. The great ocean currents help distribute heat from place to place by gradually releasing it into Earth’s atmosphere. Warm surface currents (such as the Gulf Stream) make high-latitude countries (such as Scotland) more habitable than they would otherwise be. Moreover, a great amount of equatorial heat is absorbed by water during evaporation. Global atmospheric currents (winds) carry the water vapor to cooler regions, and heat is released to the atmosphere as the vapor condenses, forming precipitation. Thus heat as well as water is transported, providing an important mechanism for evening out temperatures on Earth. Air in contact with large bodies of water is tempered—warmed in the winter and cooled in the summer. The amount and distribution of precipitation depend a great deal on the surface temperature of the water. When water temperatures do change, even a little, large changes in weather patterns may occur. A good example of this is the ENSO (El Niño/Southern Oscillation) cycle, which brings especially wet and dry seasons to many places around the world. 4. c. Students know the causes and effects of different types of severe weather. Many types of severe weather are in the world: hurricanes, tornadoes, thunder-storms, and monsoons. The source of energy for all weather is the Sun, which heats air and water unevenly. Warm air tends to be less dense than cold air, and air will always flow (blow) from areas of high pressure (denser air) toward areas of lower pressure, creating winds. With increasing temperature, more water can evaporate into the air. When this warm, moist air is suddenly cooled (as by contact with a cold air mass), condensation and precipitation may result. The contacts between air masses with different temperatures are called fronts. When a patch of warm, low-pressure air is surrounded by higher-pressure air (called a low-pressure “closure”), the warmer air will tend to rise and be replaced, through convection, by high-pressure air flowing in from all around. Because Earth rotates on its axis, all such winds are deflected (turned to the right in the Northern Hemisphere and to the left in the Southern); the net effect is a circular wind, which surrounds the low-pressure closure. The rising warm air in the center cools, its water condenses, and precipitation occurs. This phenomenon is known as a cyclone and is the cause of many big hurricanes and other storms. 4. d. Students know how to use weather maps and data to predict local weather and know that weather forecasts depend on many variables. Weather maps display data on air temperature, air pressure, and precipitation. If students know that air flows from regions of high pressure to regions of low pressure (and turns to the right in the Northern Hemisphere), they can look at a weather map and predict the direction of the wind. If they know, for example, that weather fronts tend to move from west to east in North America, they can predict tomorrow’s weather in one place by checking on today’s weather somewhere else. And if they see low-pressure closures (discussed above), they can predict stormy or fair weather from high-pressure closures. Very small changes in temperature and pressure, however, may significantly change all such patterns over a few days (the so-called chaos theory). Long-term weather forecasts tend to be unreliable for this reason. 4. e. Students know that the Earth’s atmosphere exerts a pressure that decreases with distance above Earth’s surface and that at any point it exerts this pressure equally in all directions. Atmospheric pressure is the weight of air (a force) pushing on a given square unit area (e.g., m2 or cm2). Air is invisible, hard to detect by the sense of touch, and difficult to weigh. Thinking of air as being able to exert pressure works against one’s intuition; nonetheless, air has mass and anything with mass is pulled by gravity to-ward Earth’s center. This principle means that atmospheric pressure is greatest near Earth’s surface at sea level and diminishes with increasing height in the atmosphere. This effect is used by airplane pilots to measure altitude reliably, with barometric pressure at sea level serving as a reference point. The principle also means the pressure exerted on the bottom of an object, such as a balloon, is slightly greater than the pressure on the top. The second part of this standard is a reminder that the direction of the “push” caused by the pressure is the same in all directions—up, down, or sideways. The same principle holds true for pressure in any fluid. STANDARD SET 5. Earth Sciences (The Solar System) (5 th) Student knowledge of the solar system includes an understanding of and the ability to describe the relative motions of the planets. Students already know that Earth orbits the Sun and the Moon orbits Earth. Students in grade five learn the composition of the Sun and that the solar system includes small bodies, such as asteroids and comets, as well as the Sun, nine planets, and their moons. They learn the basic relationship between gravity and the planetary orbits. 5. The solar system consists of planets and other bodies that orbit the Sun in predictable paths. As a basis for understanding this concept: 5.a. Students know the Sun, an average star, is the central and largest body in the solar system and is composed primarily of hydrogen and helium. The Sun is about one million times the volume of Earth. Its mass can be calculated from the shapes of the planetary orbits, which result from the gravitational attraction between the Sun and its planets. The fusion of hydrogen to helium produces most of the Sun’s energy. 5. b. Students know the solar system includes the planet Earth, the Moon, the Sun, eight other planets and their satellites, and smaller objects, such as asteroids and comets. The solar system comprises nine planets, in the following order from the Sun: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto. Most of the planets have moons in orbit about them, but only Earth’s moon is visible to the unaided eye. Asteroids and comets are small bodies, most of which are in irregular orbits about the Sun. Many science texts and Web sites provide information and photographs of objects in the solar system that are collected from NASA’s planetary, comet, and asteroid missions and from the use of Earth and space telescopes. 5. c. Students know the path of a planet around the Sun is due to the gravitational attraction between the Sun and the planet. Planets move in elliptical but nearly circular orbits around the Sun just as the Moon moves in a nearly circular orbit around Earth. Each object in the solar system would move in a straight line if it were not pulled or pushed by a force. Gravity causes a pull, or attraction, between the mass (matter) of each of the planets and the mass (matter) of the Sun. This pull is what continually deflects a planet’s path toward the Sun and produces its orbit. Students may wonder why the pull of gravity does not cause the planets to “fall” into the Sun or the Moon into Earth. One explanation is that the planets and Moon are in fact falling, but they are also moving very fast to the side. As the Moon is pulled toward Earth, it also moves forward creating the curved path of its orbit. Thus the Moon is constantly falling, but the downward and sideways motions are exactly balanced so that the Moon never gets closer to or farther away from Earth. In the same way the planets are maintained in orbits around the Sun. Understanding that gravity exists in outer space may be made more difficult by the images of astronauts floating “weightless” in their capsules. When these pictures are taken, the astronauts are in orbit around Earth and are essentially free-falling (just like the Moon). STANDARD SET 6. Investigation and Experimentation (5 th) Questions that are testable in science are founded on factual information and are based on observations. When students plan an experiment on the basis of their questions, they must decide what the variables are or what properties or sequence of events will change throughout the experiment. Students will observe and measure a change in one of the properties or event sequences in their experiment. The experiment is complete when the students draw conclusions and make inferences in a written or oral report or in both. 6. Scientific progress is made by asking meaningful questions and con-ducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will: a. Classify objects (e.g., rocks, plants, leaves) in accordance with appropriate criteria. b. Develop a testable question. c. Plan and conduct a simple investigation based on a student-developed question and write instructions others can follow to carry out the procedure. d. Identify the dependent and controlled variables in an investigation. e. Identify a single independent variable in a scientific investigation and explain how this variable can be used to collect information to answer a question about the results of the experiment. f. Select appropriate tools (e.g., thermometers, meter-sticks, balances, and graduated cylinders) and make quantitative observations. g. Record data by using appropriate graphic representations (including charts, graphs, and labeled diagrams) and make inferences based on those data. h. Draw conclusions from scientific evidence and indicate whether further information is needed to support a specific conclusion. i. Write a report of an investigation that includes conducting tests, collecting data or examining evidence, and drawing conclusions. |
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STANDARD SET 1. Plate Tectonics and Earth’s Structure (6 th) Plate tectonics is a unifying geologic theory that explains the formation of major features of Earth’s surface and important geologic events. Although most scientists today consider Alfred Wegener to be the pioneer of the modern continental drift theory, he died with very little recognition for his accomplishment. Wegener asserted that evidence on Earth’s surface indicated that the continents were once attached as an entire land mass. He theorized that this land mass broke up into pieces that subsequently drifted apart. Today, geologists know that plate tectonic processes are responsible for most of the major features of Earth’s crust (including continental configuration, mountains, island arcs, and ocean floor topography) and are an important contributor to the recycling of material in the rock cycle. Driven by the flow of heat and material within Earth, these processes cause stresses in Earth’s crust that are released through earthquakes and volcanic activity. Mountain building counters the constant destructive effects of weathering and erosion that eventually wear down Earth’s surface features. 1. Plate tectonics accounts for important features of Earth’s surface and major geologic events. As a basis for understanding this concept: a. Students know evidence of plate tectonics is derived from the fit of the continents; the location of earthquakes, volcanoes, and mid-ocean ridges; and the distribution of fossils, rock types, and ancient climatic zones. Evidence of past plate tectonic movement is recorded in Earth’s crustal rocks, in the topography of the continents, and in the topography and age of the ocean floor. Continental edges reflect that they were once part of a single large supercontinent that Wegener named Pangaea. Upon the breakup of this supercontinent, the individual continents were moved to their present locations by the forces that drive plate tectonics. When the continental plates of today are returned to their super-continent positions (through computer modeling), the fossil and sedimentary evidence of ancient life distributions and climate becomes coherent, providing strong support for the existence of Pangaea. As plates move in relation to one another, landforms and topographic features, such as volcanoes, mountains, valleys, ocean trenches, and midocean ridges, are generated along plate boundaries. Those regions are also frequently associated with geothermal and seismic activity. There is strong evidence that the divergence and convergence of the lithospheric plates did not begin and end with Pangaea but have been going on continually for most of the history of Earth. Students should read and discuss expository texts that explain the process of continental drift and study maps that show the gradual movement of land masses over millions of years. Students may then model the process by cutting out continental shapes from a map of Earth and treating these continents as movable jigsaw puzzle pieces. Students read about the underlying evidence for continental drift and determine that the best-supported model of Pangaea shows a continuation of major geologic features and fossil trends across continental margins. The “broken” pieces of Pangaea can be gradually moved into their modern-day continental and oceanic locations. In doing this students should think carefully about the rate and time scale of the movement. This would be a good point in the curriculum to introduce the differing compositions of the denser ocean floor (basaltic) rock and less-dense continental (granitic) rocks. Students can also learn why most modern-day earth-quakes and volcanoes occur at the “leading edges” of the moving continents. 1.b. Students know Earth is composed of several layers: a cold, brittle lithosphere; a hot, convecting mantle; and a dense, metallic core. Earth is not homogeneous solid rock but is composed of three distinct layers: a rocky, thin, fractured outer layer called the crust; a denser and thick middle layer called the mantle; and a dense, metallic center called the core. Geologists also use another classification scheme in which the outer, brittle layer of Earth is called the lithosphere (from the Greek lithos for rock). The lithosphere includes the crust and the outermost portion of the mantle and is the part that is broken into the tectonic plates. Students should know the properties of the crust, mantle, core, lithosphere, and plastic mantle region just beneath the lithosphere called the asthenosphere. Temperature increases with increasing depth as a consequence of the heat re-leased by the decay of trace quantities of radioactive atoms that are contained within Earth. Heating lowers the density of parts of the interior. Because an arrangement of high-density material over low-density material cannot be gravitationally stable, a vertical flow called convection develops. This convection can be sustained as long as the interior continues to be heated, causing a continuous cycling within Earth’s interior. Scientists gather evidence for the details of Earth’s layered structure from the analysis of seismic P and S waves as they pass through the planet. The content of this standard can be learned efficiently by the study of a cross-sectional model or diagram of Earth showing locations (to scale) of the crust, mantle, and core with each subdivision labeled according to temperature, density, composition, and physical state. 1. c. Students know lithospheric plates the size of continents and oceans move at rates of centimeters per year in response to movements in the mantle. Convective flow in the mantle moves at rates measured in centimeters per year, about as fast as fingernails grow. Mantle motion is transferred to the lithosphere at its boundary with the asthenosphere. As a result of this coupling, the lithospheric plates are carried passively along, riding as “passengers” at the same slow rate, in much the same way that ice floats along on slow-moving water. These lithospheric plates may be oceanic (i.e., they consist of rocks of basaltic composition) or continental (i.e., they consist of a more varied suite of rocks, mostly of granitic composition, covered in many places with a thin veneer of sedimentary rocks). Convective flow is based on the “rising” and “sinking” of materials with different relative densities. Just as a hot-air balloon rises through lower temperature and therefore denser air, hot convecting mantle can rise through lower temperature and therefore denser rock, albeit very slowly. When the material cools and increases in density, it may sink just like the hot-air balloon once the air inside has cooled. Oceanic lithosphere cools after it forms at Earth’s surface and can eventually become dense enough that it will sink into Earth’s interior, sliding under an adjacent plate that is less dense. 1. d. Students know that earthquakes are sudden motions along breaks in the crust called faults and that volcanoes and fissures are locations where magma reaches the surface. The hot, moving mantle is responsible for many geologic events, including most seismic and volcanic activity. As a result of the relative motion of the lithospheric plates, the boundaries of the plates are subjected to stresses. When the rocks are strained so much that they can no longer stretch or flow, they may rupture. This rupture is manifested as sudden movement along a broken surface and is called a fault. The energy released is spread as complex waves (called earthquakes) that travel through and around Earth. Volcanic phenomena, including explosive eruptions and lava flows, may also result from interactions at the boundaries between plates. Molten gas-charged magma generated in the crust or mantle rises buoyantly and exerts an upward force on Earth’s surface. If these rocks and gases punch through the surface, they result in a variety of volcanic phenomena. Using California-adopted texts, software, and other instructional materials aligned with the Science Content Standards, students can study models of the inner structures of volcanoes, the dynamics of the central crater, and the processes of erupting and flowing lava. Students can study the various types of volcanoes and how they form. They can also learn about different types of lava flows and the three major types of volcanic landforms (cone, shield, and composite). 1.e. Students know major geologic events, such as earthquakes, volcanic eruptions, and mountain building, result from plate motions. Most (but not all) earthquakes and volcanic eruptions occur along plate boundaries where the plates are moving relative to one another. The movement is never smooth; it may produce fractures or faults and may also generate heat. The sudden shift of one plate on another plate along faults causes earthquakes. Volcanic eruptions may occur along faults in which one plate slides under another and sinks deep enough to melt part of the descending material. This process of one plate sliding under another is called subduction. Great mountain-building episodes occur when two continental plates collide. The collision (although slow) is enormously powerful because of the mass of the continents. Over long periods of time, this process may crumple and push up the margins of the colliding continents. Students may use a large map of the world or of the Pacific Ocean (including the entire Pacific Ocean Rim) to plot the locations of major earthquakes and volcanic eruptions during the past ten to 100 years. The locations of those tectonic events may be found on the Internet or in various library resources. Different symbols may be used to represent different depths or magnitudes of events. In studying such a map, students should note that tectonic events form a “ring” that outlines the Pacific Plate and that there is a Hawaiian “hot spot.” Landforms associated with the plate boundaries include mountain belts, deep ocean trenches, and volcanic island arcs. 1.f. Students know how to explain major features of California geology (including mountains, faults, volcanoes) in terms of plate tectonics. Most of California resides on the North American lithospheric (continental) plate, one of the several major plates, and many smaller plates that together form the lithosphere of Earth. A small part of California, west of the San Andreas Fault, lies on the adjacent Pacific (oceanic) Plate. Geologic interactions between these two plates over time have created the complex pattern of mountain belts and intervening large valleys that make up the current California landscape. Large parts of the central and southern parts of California were once covered by a shallow sea. Inter-actions with the Pacific Plate during the past few million years have compressed, fractured, and uplifted the area. This tectonic deformation has buckled the lithosphere upward to create the high-standing coastal and transverse mountain ranges and downward to form the lower-lying Central Valley, Los Angeles Basin, and Ventura Basin. 1.g. Students know how to determine the epicenter of an earthquake and know that the effects of an earthquake on any region vary, depending on the size of the earthquake, the distance of the region from the epicenter, the local geology, and the type of construction in the region. An epicenter is that point on Earth’s surface directly above the place of an earthquake’s first movement, or focus. It is located by seismic data recorded at a minimum of three seismograph stations. The method of locating the epicenter is based on the speed of seismic waves that travel through the ground—seen as their relative times of arrival at seismic stations. These vibrations are called P-and S-waves. P-, or primary, waves are compressional with particle motion in the same direction as the wave propagation. S-, or secondary, waves are shearing with particle motion perpendicular to the direction of wave propagation. S-waves travel at about 60 percent of the speed of P-waves. The motion of P-and S-waves and the difference in their respective velocities are easily modeled with a long and flexible spring (typically sold as a toy). Compressing and releasing a few coils at the end of the spring stretched between two students generates visible P-waves that travel the length of the spring and back in the opposite direction. Slapping the side of the spring generates S-waves that travel as sideways displacements down the length of the spring. If students measure the distance between the ends of the spring and the time it takes for the P-and S-waves to travel the full length, they can calculate the different velocities of the two waves along the spring. Seismographs record the arrival time of the P-and S-waves. The knowledge that both waves started at the same time allows one to determine the distance of the epicenter. If three or more seismographs record distances to the same event, the epicenter of the earthquake may be determined by triangulation. Students in grade six can be taught to locate epicenters if they are given the arrival times at various locations on a map, along with a simple velocity model. They may also be asked to locate major geologic features in and near California, such as Mount Lassen, the San Andreas Fault, the Sierra Nevada ranges, Death Valley, the Baja Peninsula, and the San Francisco Peninsula. They can draw and relate these to a map that includes outlines of the major tectonic plates. California’s population is primarily concentrated near the San Andreas Fault and the system of faults that surround it. Students can plot on a map the location of their school and nearby active faults and research records of earthquake activity, ground motion, and fracturing. Seismograph stations also record the amplitude of the ground motion, which can be used to calculate the magnitude of an earthquake (a relative measure of the amount of energy released). Magnitude is often reported according to the Richter scale, with values that generally range from around 0 to a little less than 9. Each increase of one number in magnitude represents a tenfold increase in ground shaking. Geologists may also investigate the effects of an earthquake on structures (and people’s reactions) and assign an intensity value to that earthquake. The intensity values are then plotted on a map to give a more complete picture of the earth-quake’s effects. There are several different intensity scales, but the one most widely used in this country is the Modified Mercalli scale. This scale ranges from I (not felt) to XII (damage nearly total). The magnitude of an earthquake is determined by the buildup of elastic strain (stored energy) in the crust at the place where ruptures (faults) may eventually occur. Unfortunately, many small earthquakes combined can release only a small fraction of the stored energy. For example, it might take as many as one million earthquakes, each at a magnitude of 4.0 on the Richter scale to release the same amount of energy as a single earthquake at 8.0. Although each increase of one number on the Richter scale reflects a tenfold increase in ground shaking, it represents nearly a thirtyfold increase in energy released. Therefore there is always a possibility that a large, destructive earthquake will release most of the stored energy. Because the materials through which earthquakes move can absorb energy and because the energy is spread over a wider area as its waves propagate outward, an earthquake tends to weaken with increasing distance from its epicenter. As earthquake waves pass through the ground, unconsolidated materials, such as loose sediments or fill, tend to shake more violently or undergo liquefaction more easily than do harder materials. Buildings made of brittle materials (e.g., reinforced concrete, brick, or adobe) tend to suffer greater earthquake damage than do those made of more flexible materials (wood). Taller buildings are often more susceptible to earthquake damage than are single story-buildings. STANDARD SET 2. Shaping Earth’s Surface (6 th) Over long periods of time, many changes have occurred in Earth’s surface features. Forces related to plate tectonics have elevated mountains. Atmospheric constituents (mostly water, oxygen, and carbon dioxide) have interacted with minerals and rocks at Earth’s surface, weakening them and breaking them down through a process called chemical weathering. Physical processes involving, for ex-ample, the growth of plants, the release of pressure as overlying material is eroded, and the repeated freezing and thawing of water in cracks, have also helped to break down rocks. Fragments are transported downslope by wind, water, and ice. Gravity by itself moves material by way of landslides and slumps (called mass wasting). The ultimate destination of most of the products of weathering is the ocean. These products arrive in the form of marine sediment deposits. In time the mountains are laid low, the rivers change their courses and disappear, and lakes and seas expand or dry up. Eventually sediments, which have found their way to the oceans along continental margins, are compacted and changed to rock, then uplifted by continental collision or subducted and melted under the crust. New mountains are formed, and the cycle (called the geologic cycle) begins anew. Each cycle takes tens of millions of years. 2. Topography is reshaped by the weathering of rock and soil and by the transportation and deposition of sediment. As a basis for under-standing this concept: 2.a. Students know water running downhill is the dominant process in shaping the landscape, including California’s landscape. Water contributes to two processes that help shape the landscape—the break-down of rock into smallerpieces by mechanical and chemical weathering and the removal of rock and soil by erosion. Water is the primary agent in shaping California’s landscape. Surface water flow, glaciers, wind, and ocean waves have all been and continue to be active throughout California and the rest of the world in shaping landscapes. A “streamtable” may be used to demonstrate the effectiveness of running water as an erosion agent. Stream tables can be easily made from plastic bins or dishpans filled with sand or gravel. The water source may be a hose, a siphon that draws from a cup, or even a drip system. Students may use either gradient or water flow rate as the independent variable. Rates of settling of different sizes of sediment through water may be demonstrated through the use of a sediment jar. 2. b. Students know rivers and streams are dynamic systems that erode, transport sediment, change course, and flood their banks in natural and recurring patterns. The energy of flowing water is great enough to pick up and carry sediment, thereby lowering mountains and cutting valleys. Sediment carried by a stream may be directed against solid rock with such force that it will cut or abrade the rock. The steeper the slope and the greater the volume-flow of water, the more energy the stream has to erode the land. The flow of water usually varies seasonally. At times of heavy rainfall in a watershed, a stream may flood and overflow its banks as the volume of water exceeds its containment capacity. Flooding may cause a stream to change its path. A stream bank, which consists of sediment or bedrock, may collapse and change the water’s course. One example of this is a stream’s tendency to shorten its length by forming oxbow lakes. This redirection of the stream’s course usually takes place in natural and recurring patterns year after year. 2. c. Students know beaches are dynamic systems in which the sand is supplied by rivers and moved along the coast by the action of waves. The final destination of sediment is usually the ocean. Coarse sediment (sand size and larger) frequently is temporarily trapped along the shore as beach deposits while the finest sediments are often washed directly out to sea and, in some cases, carried by ocean currents for many miles. Waves that break at oblique angles to the shore move sediment along the coast. Waves wash the sand parallel to the direction in which they break, but the return water-flow brings sand directly down the slope of the beach, resulting in a zigzag movement of the sand. Students can observe differences in sand (e.g., size, color, shape, and composition) by using sand collections that may be obtained from various sources, including family and friends. The differences result from the variety of rock sources from which the sand has come, the weathering processes to which the rock has been subjected, and the completeness of the weathering (i.e., how long the rock has been subjected to weathering). Students should attempt to identify any minerals or rocks that would indicate the kinds of weathered materials contained in the sand. Students examining sand from California beaches will find constituents such as quartz, feldspar, shell fragments, and magnetite. Magnetite is fun to extract by passing a magnet, wrapped in a plastic bag, through the sand. Magnetite may be saved and later used in place of iron filings to demonstrate magnetic field geometry for another standard. 2. d. Students know earthquakes, volcanic eruptions, landslides, and floods change human and wildlife habitats. Earthquakes can collapse structures, start fires, generate damaging tsunamis, and trigger landslides. Landslides can destroy habitats by carrying away plants and animals or by burying a habitat. Volcanic eruptions can bury habitats under lava or volcanic ash, ignite fires, and harm air quality with hot toxic gases. Floods can bury or wash away habitats. Lives may be lost and property damaged when humans get in the way of those powerful natural processes. Although construction (and human habitation) in areas prone to natural disasters is often impossible to avoid, understanding the likelihood of such disasters and taking steps to mitigate the potential effects would be wise. Moreover, no construction too close to known hazards (e.g., on floodplains) would be advisable. Certainly, the frequency (probability) and severity of flooding, land-slides, and earthquakes must be considered when one decides on land use. Making those decisions should be done after consideration of many factors, including the use of scientific evidence to predict catastrophic events and the local impacts. Although catastrophic events are usually adverse in the short term, some of them may be beneficial in the long term. For example, river floods may deliver new, nutrient-enriched soil for agriculture. Other catastrophic changes may introduce new habitats, allow fresh minerals to surface, change climates, or give rise to new species. STANDARD SET 3. Heat (Thermal Energy) (Physical Science) (6 th) Prior to the nineteenth century, the transfer of heat was assumed to be due to the flow of a substance called caloric, an invisible, weightless fluid whose total quantity remained constant. The caloric theory subscribed to the belief that an object became hot when it was permeated by a large quantity of caloric and cooled when some of its caloric flowed into other objects that had less caloric. This model was upset by the work of two scientists: Benjamin Thompson (later known as Count Rumford) and James Joule. Rumford supervised the boring of cannons. He noted that the water kept in the bores to prevent overheating boiled continuously. This boiling was supposedly caused by the caloric that flowed from the metal of the cannon as it was cut. From his observations, however, Rumford deduced that this explanation could not be correct because the boiling continued even when the boring tool became so dull that it no longer had any effect on the metal. Apparently, the caloric was being produced out of nothing. Rumford concluded that it was the work needed to turn the dull tool, instead of caloric transfer, that was being converted into heat. In a series of experiments, Joule showed that a given amount of mechanical work always produced the same amount of heat no matter what kind of mechanical work was done. This demonstration established that heat is indeed a form of energy. Today, it is known that heat is energy contained in the random motion of atoms and molecules and that to heat an object is to increase the energy so stored. Although students will not be exposed to kinetic molecular theory until high school, teachers who understand the following points will be better able to discuss the subjects of heat and heat transfer. The transfer of heat from a warmer object to a colder object is referred to as heat flow. Heat may be transferred by conduction, convection, or radiation. Standard Sets 3 and 4 in grade six deal in depth with the relationships between heat and convection in Earth’s mantle, oceans, and atmosphere. Material covered in those standards will build a foundation for the study of heat. Students will learn that atoms are free to move in different ways in solids, liquids, and gases and that heat may be given off or absorbed during chemical reactions. The concept that heat is a form of energy associated with the motion of atoms and molecules is covered in high school. Students in grade six will study the relationship between work and heat flow and will be required to solve problems related to this subject. 3. Heat moves in a predictable flow from warmer objects to cooler objects until all the objects are at the same temperature. As a basis for understanding this concept: 3. a. Students know energy can be carried from one place to another by heat flow or by waves, including water, light and sound waves, or by moving objects. Energy is transferred from one object to another as the result of a difference in temperature. Heat flow is the transfer of energy from a warmer object to a cooler object. A wave is an oscillating disturbance that carries energy from one place to another without a net movement of matter. For example, sound waves from one vibrating object can cause other objects, such as eardrums, to vibrate. Electromagnetic waves can also carry energy. One example of this phenomenon is the transfer of heat from the Sun to Earth. Students may think of the infrared radiation escaping from a bed of hot coals and warming their hands as another example of heat flow. Energy can also be transferred by the movement of matter. For example, the energy supplied by the pitcher’s arm transports a pitched baseball to the catcher’s mitt. 3. b. Students know that when fuel is consumed, most of the energy released becomes heat energy. When fuel is burned, energy stored in the fuel’s chemical bonds is released as heat and light. Only a small portion of the energy contained in the original fuel remains locked in the waste products left over after the fuel has been consumed. Although the heat derived from fuels is often used in turn to drive engines that perform useful work, an important understanding is that even the work performed ultimately tends to be transformed into heat. For example, an automobile set into motion and braked to rest transforms most of its kinetic energy into heating the brake pads by friction. As a demonstration the teacher might light a candle in the classroom and let students know that the wax in the candle is the fuel that combines with oxygen in the air to produce both heat and light. Most of the heat is transferred to the room by the hot gases rising from the flame. Glowing particles of soot (the source of the yellow light) also transfer energy from the flame. Students might be asked to develop an explanation of how heat is transferred from the burning fuel to a container of water heated by the candle, using the concepts and principles called for in this standard set. 3. c. Students know heat flows in solids by conduction (which involves no flow of matter) and in fluids by conduction and by convection (which involves flow of matter). This standard focuses on differences between heat transfer by conduction and by convection and begins to build an understanding of the kinetic molecular theory of heat transfer. In both solids and fluids (liquids and gases), heat transfer is measured by changes in temperature. Conduction occurs when a group of atoms or molecules whose average kinetic energy is greater than that of another group transfers some of that excess energy by means of collisions. Because hot objects have atoms with greater average kinetic energy than do cold ones, there is a transfer of this kinetic energy from hot to cold. In a solid the atoms vibrate in place, but energy may still be transferred from atom to atom as happens when a pan is placed on a stove and its handle becomes hot. The same mechanism describes the conduction of heat in liquids and gases, where the atoms are free to slip past one another provided there is no cumulative flow in the material. To demonstrate conduction a teacher might wrap some paper (to form a handle) around the end of a metal rod about 30 centimeters long and use paraffin to attach a series of thumbtacks, spaced about two centimeters apart, along the rod. The teacher then holds the rod by the handle and places the free end over a candle or in a burner flame. As heat is conducted along the rod, the tacks drop away one by one. Convection occurs because most fluids become less dense when heated; the hot fluid will rise through cold fluid because of the hot fluid’s greater buoyancy. As hot fluid arises away from a heat source, it may cool, become denser, and sink back to the source to be warmed again. The resulting circulation is called a convection current. Convection currents account for the water in a kettle reaching a uniform temperature although the kettle is warmed only at the bottom. The effects of convection may be investigated by placing finely shredded paper into a large heat-resistant beaker or roasting pan filled with cold water. After the paper is saturated and sinks to the bottom of the container, the teacher may apply heat from a hot plate and note that the paper particles move upward near the heat source and downward away from it. 3. d. Students know heat energy is also transferred between objects by radiation (radiation can travel through space). Another form of energy transfer between objects is radiation: the emission and absorption of electromagnetic waves. Radiation is fundamentally different from conduction and convection in that the objects do not have to be in contact with each other or be joined by a solid or fluid material. Heating by sunlight is an obvious example of radiant energy transfer. Both the heat and the light that can be seen are forms of electromagnetic radiation. Calling attention to this fact may help dispel the common misconception that all radiation is harmful. STANDARD SET 4. Energy in the Earth System(6 th) Energy that reaches Earth’s surface comes primarily as radiation from the Sun. Solar energy includes the full electromagnetic spectrum, but most of it is carried in the visible region. Because the atmosphere is transparent to visible light, most of this incoming energy is transferred to Earth’s surface. Conductive transfer and reradiation of this energy heat the lower atmosphere and result in convection currents that distribute the heat into the atmosphere. Solar radiation heats Earth’s surface unevenly, resulting in thermal gradients in the atmosphere. Variations in the angle of sunlight influence the amount of energy reaching each square meter of Earth’s surface and largely account for the uneven heating of the surface. The angle of sunlight varies because of Earth’s spherical shape and because the Sun’s rays travel in a straight line parallel to one another. If a surface area of this planet is directly perpendicular to the Sun (meaning the Sun is directly overhead), then the rays strike at a 90-degree angle, resulting in maximum absorption of solar radiation because the energy is concentrated on a relatively small area. As the surface curves away from this spot, the angle at which sunlight strikes it becomes smaller, and the same amount of solar radiation is spread over a broader area. The uneven heating of Earth’s surface and the tilt of its axis (66.5 degrees to the orbital plane or 23.5 degrees to the perpendicular) account for the seasons and extremely cold north and south poles. Clouds and the varied reflectivity of Earth’s surface contribute to uneven heating. In general, however, the total solar energy transferred to Earth is nearly constant, and all the energy gains and losses are in balance. Consequently, Earth enjoys climates that are relatively stable for thousands of years, with predictable temperature ranges and weather patterns that can be broadly forecast. Various heat exchange mechanisms operate in the Earth system. Ocean surface water is heated by the Sun and mixed by convection currents. The atmosphere ex-changes heat with the oceans and land masses by means of conduction. Warm air near Earth’s surface rises and cooler air descends, causing atmospheric convection currents. Different parts of the ocean have different temperatures and salinities, resulting in deep convection currents. The convection currents in the atmosphere move evaporated water away from ocean surfaces; from there the water vapor can be picked up by winds and carried to other locations where it may condense as precipitation. In this manner both heat and water are transported. The observed patterns of surface winds are mostly the result of convection cur-rents caused by uneven surface heating. Winds are deflected by the Coriolis effect (caused by the west-to-east turning of Earth) and by topography. Latitude, winds (speed, direction, and moisture content), and the elevation of the land and its proximity to the ocean largely determine the climate and corresponding weather pat-terns in any particular region. Earth’s crust contains localized concentrations of internal heat, as evidenced by volcanoes, hot springs, and geysers. However, the total amount of heat transferred to the atmosphere from Earth’s crust is minute compared with the amount of heat the surface receives from the Sun. 4. Many phenomena on Earth’s surface are affected by the transfer of energy through radiation and convection currents. As a basis for understanding this concept: 4. a. Students know the sun is the major source of energy for phenomena on Earth’s surface; it powers winds, ocean currents, and the water cycle. Radiation from the Sun penetrates the atmosphere by heating the air, the oceans, and the land. Solar radiation is also converted directly to stored energy in plants through photosynthesis. The Sun is a constant, close-to-uniform source of energy that is responsible for the climate and weather, drives the water cycle, and makes life possible on Earth. 4. b. Students know solar energy reaches Earth through radiation, mostly in the form of visible light. A full-wavelength spectrum of electromagnetic energy is present in solar radiation from below the infrared to above the ultraviolet. However, most of the energy radiated by the Sun is in the visible or near visible part of the light spectrum, and that is largely the part that penetrates the transparent atmosphere and reaches Earth’s surface. Because blue light is scattered by the atmosphere more than yellow light, the sky looks blue and the Sun looks yellow. Students should understand that both long- and short-wavelength radiation may interact in various ways with atmospheric constituents and may be absorbed by atmospheric constituents in different amounts; however, the wavelengths of visible light are not greatly absorbed by any atmospheric constituent. 4. c. Students know heat from Earth’s interior reaches the surface primarily through convection. Heat from the interior of Earth moves toward the cooler crustal surface. Rock is a poor conductor of heat; therefore, most of the transfer of heat occurs through convection. Convection currents in the mantle provide the power for plate tectonic movements. Heat reaching Earth’s surface in this manner is transferred to the atmosphere in relatively small amounts. 4. d. Students know convection currents distribute heat in the atmosphere and oceans. Convection plays a central role in transferring heat energy from place to place in the atmosphere and ocean. Uneven heating of the land and ocean causes convection currents. This movement of air and water creates the wind and ocean currents that are deflected by the geography of the land and the rotation of Earth. Students can investigate atmospheric convection currents on a small scale by using a smoke chimney or fog chamber. In the absence of more sophisticated equipment, much can be observed about atmospheric convection by studying what happens to visible water droplets (condensing steam) as they exit a boiling teakettle. There are several ways to investigate convection currents in a liquid. One way is to float a large ice cube (tinted with food coloring) on hot water and trace the resulting convection currents. Another way is to heat one end of an elongated cake pan full of water. Convection may be observed by adding drops of food coloring. 4. e. Students know differences in pressure, heat, air movement, and humidity result in changes of weather. Changes in local temperatures, atmospheric pressure, wind, and humidity create the weather that everyone experiences. All those effects are connected directly to the processes associated with the transfer of solar energy to Earth and redistribution of that energy in the form of heat. Precipitation occurs when moist air is cooled below its condensation temperature (dew point). Great currents circle the globe in the convecting atmosphere and ocean, created by atmospheric pressure and temperature gradients that, in turn, spin off local winds and eddies. Temperature differences also lead to changes in humidity and precipitation. The local set of these descriptive measures is called weather, and the changes result in weather patterns. The long-term seasonal average of these weather patterns defines the climate of an area. STANDARD SET 5. Ecology (Life Sciences) (6 th) All living organisms are a part of dynamic systems that continually exchange energy. These systems are regulated by both biotic and abiotic factors. Nutrients needed to sustain life in an ecosystem are cycled and reused, but the energy that flows through the ecosystem is lost as heat and must constantly be renewed. Green plants are the foundation of the energy flow in most ecosystems because they are capable of producing their own food by photosynthesis. Because energy is either used by consumers or depleted in a logical progression, it can be said to flow through a food web (also known as a food chain). A food web may be represented as an energy pyramid with green plants as a base, midlevel consumers in the middle, and a few top-level predators at the apex. Scavengers and decomposers are the final members of an energy pyramid as they clean up the environment and return matter (nutrients) to Earth. A food web can also show the various roles played by plants and animals as producers, consumers, and decomposers. 5. Organisms in ecosystems exchange energy and nutrients among themselves and with the environment. As a basis for understanding this concept: 5. a. Students know energy entering ecosystems as sunlight is transferred by producers into chemical energy through photosynthesis and then from organism to organism through food webs. A food web depicts how energy is passed from organism to organism. Plants and photosynthetic microorganisms, or producers, are the foundation of a successful food web because they do not need to consume other organisms to gain energy. Instead, they gain their energy by transforming solar energy through photosynthesis into chemical energy that is stored in their cells. 5. b. Students know matter is transferred over time from one organism to others in the food web and between organisms and the physical environment. Energy and matter are transferred from one organism to another organism through consumption. Plants are eaten by primary consumers (herbivores); most herbivores are eaten by secondary consumers (carnivores); and those consumers are eaten by tertiary consumers (often top-level predators). At the microscopic scale photosynthetic bacteria (cyanobacteria) and protists or single-celled eukaryotic organisms (e.g., dinoflagellates) are consumed by heterotrophic protists (e.g., amoebae and ciliates), which are also called protozoans. Protozoans are consumed by other larger protozoans and by small animals such as cnidarians, arthropods, and nematodes. Energy is transferred from organisms (microorganisms, plants, fungi, and animals) to the physical environment through heat loss. Carbon is returned to the physical environment as airborne carbon dioxide through the respiration of organisms. Water is also cycled. Students may use science texts and other library materials to research organisms included in the food webs of particular ecosystems. Students can draw model food webs to demonstrate how food energy is transferred from plants to consumers and from consumer to consumer through predation. Students can also depict the hierarchy of consumers and the transfer and loss of energy from herbivores through secondary consumers to the top carnivores in a food web or energy pyramid. Students should know that energy is lost to the physical environment at every hierarchical level.
5. c. Students know populations of organisms can be categorized by the functions they serve in an ecosystem. Organisms in a population may be categorized by whether they are producers of chemical energy from solar energy (e.g., plants and photosynthetic microorganisms) or consumers of chemical energy (e.g., animals, fungi, and heterotrophic protists) and, if they are consumers, whether they are predators, scavengers, or decomposers. Many consumers may be categorized in multiple ways, such as omnivores that eat both plants and animals and opportunistic consumers that act as both predators and scavengers. Teachers may provide the class with a nonordered, noncategorized list of four or five plants, eight to ten consumers (four or five primary consumers, three or four secondary consumers, and one or two tertiary consumers [or top-level predators]), one or two decomposers, and one or two scavengers. Using a science text or appropriate research materials from the school library, students can identify the organisms by food web order and ecological function. Students can then arrange the organisms into an energy pyramid with the decomposers and scavengers identified and noted separately. The final task is to draw arrows between members of the pyramid to depict the predation sequence.
5. d. Students know different kinds of organisms may play similar ecological roles in similar biomes. Ecological roles are defined by the environment and not by any particular organism. For example, Australia has plants that are unique to that continent yet play the same role as other kinds of plants in similar environments elsewhere. In the rain forests of South America, the mammalian consumers and predators are placental (nonmarsupial) sloths, deer, monkeys, rodents, and cats. In the rain forests of Australia, marsupial kangaroos, wallabies, bandicoots, and so forth play the same ecological roles. Students may be assigned or may choose to research specific organisms that occupy similar biomes in widely separated geographic locales. Students should be encouraged to use a variety of library resources, such as expository texts, the Internet, CD-ROM reference materials, videos, laser programs, or periodicals. McGH. Unit 4, ch7, Ch 8 also CA18-23 5. e. Students know the number and types of organisms an ecosystem can support depends on the resources available and on abiotic factors, such as quantities of light and water, a range of temperatures, and soil composition. There is a greater variety of types of organisms in temperate or tropical environments than in deserts or polar tundra. The number of organisms supported by an ecosystem also varies from season to season. More organisms thrive during temperate summers than can survive icy winters. More organisms can multiply during a desert’s cooler, wetter winters than can live through its hotter, drier summers. Students should understand that the richness of plant growth controls the diversity of life types and number of organisms that can be supported in an ecosystem (the base of the pyramid). Richness of plant growth depends on abiotic factors, such as water, sunlight, moderate temperatures, temperature ranges, and composition of the soils. To support vigorous growth, soils must contain sufficient minerals (e.g., nitrogen, phosphorus, potassium) and humus (decomposed organic materials) without excess acidity or alkalinity. The teacher may point out that the number of plant-eating animals in an ecosystem depends directly on the available edible plants, and the number of predators in a system depends on the available prey. STANDARD SET 6. Resources(6 th) Although this standard set deals with the concept of finite resources, the emphasis is on energy. Much of the energy used worldwide is derived from nonrenewable fossil fuels, such as coal, oil, and natural gas. Those resources are being consumed at rates far faster than their geologically slow formation rates. Uranium (for fission energy) and deuterium (for fusion energy) are also finite but are in abundant supply (deuterium is almost inexhaustible). Industrial waste and pollution result from nuclear power generation and the burning of fossil fuels. The extraction (mining) and processing (smelting) of both energy and non-energy resources also have environmental consequences. There are numerous types of renewable energy resources, including solar, wind, hydroelectric, and geothermal, but they are largely undeveloped or underdeveloped. Knowing the forms, conversion processes, end-uses, and impact of wastes involved in using natural resources, whether for energy or materials, is critical in making decisions and trade-offs about how those resources will be used. 6. Sources of energy and materials differ in amounts, distribution, usefulness, and the time required for their formation. As a basis for understanding this concept: 6. a. Students know the utility of energy sources is determined by factors that are involved in converting these sources to useful forms and the consequences of the conversion process. Useful energy sources are those that can be converted readily to forms of energy needed for heat, light, and transportation. Technologies have been developed to convert various forms of energy (e.g., oil, gas, solar, nuclear, wind, and wave) to meet those needs. For example, manufacturers have learned how to refine oil to make gasoline, which can then be used in the combustion engine to provide transportation or in power generators to produce electricity. The energy sources considered the most useful are those for which the most cost-effective conversion technologies have been developed. For transportation purposes solar energy is not considered as useful mainly because inexpensive and efficient solar energy storage systems have yet to be developed. Until those systems are developed, solar energy will not be able to meet the demand for reliable levels of power or provide a driving range comparable to that provided by gasoline and diesel fuels. Students should be taught the concept of non monetary costs of energy. Mining coal leaves large, open pits and may pollute the atmosphere with the exhaust of heavy mining machinery. Power plants may also pollute the atmosphere with the exhaust from burning fossil fuels. Nuclear power plants must exhaust excess heat, often in the form of hot water introduced into rivers and oceans. Hydroelectric energy, although it is renewable and has no effect on air quality, requires the damming of streams—a measure that carries upstream environmental implications and downstream consequences on sediment load and beaches as well as the possibility of disaster caused by dam failures. Students may use published materials and Internet resources (consistent with Internet-use policies in effect at the school) to research, evaluate, and report on the environmental consequences. In this way they can develop a clearer understanding of the nonmonetary costs of energy in relation to environmental protection (conservation). Students can rate the environmental advantages and disadvantages of heating a home with electricity, natural gas (or propane), solar power, oil, or coal. McGH: Unit 5, ch10 mainly 6. b. Students know different natural energy and material resources, including air, soil, rocks, minerals, petroleum, fresh water, wildlife, and forests, and know how to classify them as renewable or nonrenewable. Renewable and nonrenewable energy and natural resources depend on both the process and the time needed to create energy sources. Solar energy cannot be exhausted nor can fuels for fusion; therefore, they are sometimes referred to as renew-able. Hydroelectric power is dependent on the water cycle (driven by solar energy) and is considered a renewable resource. Because biomass will grow back quickly to replace that used for fuel or materials, it is also considered renewable. However, if habitats and species are lost in the process of harvesting the biomass, the resources are nonrenewable in that sense. Trees used for fuel or building materials can be replaced only if the rate of use does not exceed the time needed to grow replacement trees and if the land is not altered to become unusable for that purpose. Fossil fuels (coal, oil, natural gas) were formed on geologic time scales and are considered nonrenewable resources. McGH: Unit 5, ch10 mainly 6. c. Students know the natural origin of the materials used to make common objects. This standard deals with the ultimate sources of common objects. Students often do not consider or even know the natural origins of commonly used goods. They must be reminded that manufactured items do not appear magically and that the ultimate cost of acquiring the objects goes far beyond the price sticker. Students can count the objects in their classroom to make an inventory and trace them back to the natural materials from which they were manufactured. Students can then classify the materials as renewable or nonrenewable. They may need to do some careful research to discover the origins of some materials. For example, a simple pencil contains wood and lead. But the pencil lead is actually a mixture of graphite and clay. If the pencil has an eraser, the rubber from a plant (or plastic from petroleum) and metal for the holder must be included. Students may realize in looking at clothing, paper, paint, tiles, windows, projectors, computers, chairs, books, chalk, crayons, brooms, and so on that plastics and synthetic materials are derived from oil. STANDARD SET 7. Investigation and Experimentation (6 th) Students are expected to formulate a hypothesis for the first time. A hypothesis is a proposition assumed as a basis for reasoning and often subject to the testing of its validity. The scientific hypothesis provides an explanation of a set of observations and may incorporate observations, concepts, principles, and theories about the natural world. Hypotheses lead to predictions that can be tested. If the predictions are verified, the hypothesis is provisionally corroborated. If the predictions are incorrect, the original hypothesis is proved false and must be abandoned or modified. Hypotheses may be used to build more complex inferences and explanations. Hypotheses always precede predictions. However, for simple investigations the hypothesis that led to a prediction may not be easily identified because of its simplicity or its complexity. Prediction follows observation in grades three to five. After grade six students should recognize and develop a hypothesis as a part of their experimental design. In grade six the focus on earth science can provide many opportunities in the Investigation and Experimentation standards to develop students’ ability to design experiments and to select and use tools for measuring and observing. 7. Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will: a. Develop a hypothesis. b. Select and use appropriate tools and technology (including calculators, computers, balances, spring scales, microscopes, and binoculars) to perform tests, collect data, and display data. c. Construct appropriate graphs from data and develop qualitative statements about the relationships between variables. d. Communicate the steps and results from an investigation in written reports and oral presentations. e. Recognize whether evidence is consistent with a proposed explanation. f. Read a topographic map and a geologic map for evidence provided on the maps and construct and interpret a simple scale map. g. Interpret events by sequence and time from natural phenomena (e.g., the relative ages of rocks and intrusions). h. Identify changes in natural phenomena over time without manipulating the phenomena (e.g., a tree limb, a grove of trees, a stream, a hillslope). |
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