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7th grade review lesson key.notebook 7th Grade SOL Review I. Scientific Investigations A. Every scientist uses a certain method when performing an experiment. Do you remember the steps of the scientific method? 1. State the problem 2. Gather information 3. Form a hypothesis 4. Perform the experiment 5. Record & analyze data 6. State a conclusion 7. Repeat the work B. A scientist wants to determine if the amount of vitamins given to a young mouse affects the growth of that mouse. The experiment is set up with two identical mice. Place the steps of the experiment in order. Write 1 in the blank next to the step that comes first, 2 in the blank next to the step that comes next, and so on. 1. _____ Each morning at the same time give each mouse a certain amount of vitamins. The amount should be the same for each mouse each day. 2. _____ Place each of the mice in it’s own cage, all cages should be exactly the same size and in the same location. 3. _____ Weigh each mouse every week for two months. Record the data (the mouse’s weight). 4. _____ Select 12 similar mice of the same age. 5. _____ Weigh each mouse before putting it in its cage. 6. _____ Feed the mice 2 grams of food each day, and make sure their water bottle is always full. 1 7th grade review lesson key.notebook C. Read each of the sample labs below and answer the questions for each lab. a. Ms. Jewell decided to test the following hypothesis: “Will the amount of water affect how much a plant will grow?” In order to test her hypothesis, she planted 10 seeds in each of 3 pots that contained Pete’s Potting Soil. The pots were given the following amounts of water each day for 10 days. Pot 1 got 50 mL of water, Pot 2 received 100 mL of water and Pot 3 received 150 mL of water. The height of each plant was recorded at the end of the experiment. i. What is the independent variable? _____________________ ii. What is the dependent variable? ______________________ iii. What is the control? ________________________________ iv. What are two of the constants? _______________________ _________________________________________________ b. Sandy heard that plants compete for space. She decided to test this idea. She bought a mixture of flower seeds and some potting soil. Into each of 4 plastic cups she put the same amount of soil. In the first cup she planted 2 seeds, in the second cup she planted 4 seeds, in the third cup 8 seeds, and in the fourth cup she planted 16 seeds. After 25 days she checked to see how many plants had grown and their height. i. What is the independent variable? _____________________ ii. What is the dependent variable? ______________________ iii. What is the control? ________________________________ iv. What are two of the constants? _______________________ _________________________________________________ 2 7th grade review lesson key.notebook D. A graph is often used to see if a relationship exists in a set of data. You can use a graph to show how one variable changes in response to another variable changing. The data in the table below was collected and placed in a data table. The data represents the rate bubbles formed on an underwater plant based on its distance from the light. Draw the line graph that illustrates the data. Distance from Bubbles per Minute Light (cm) 10 40 20 20 30 10 40 5 1. Which axis does the IV go on? __________ 2. Which axis does the DV go on? __________ 3. What is the IV? _______________ 4. What is the DV? ______________________ What is the relationship between the variables in this lab? ___________________________________________________ 3 7th grade review lesson key.notebook E. Drawing Conclusions The data in the table to the right shows the growth of two newborn organisms over 600 days. Individual A received a drug in its food. Individual B did not receive the drug. 1. Over the course of 600 days, what happens to the weight of each individual? _______________________________________ 2. What is the weight of each individual at birth (0 days)? ______ 3. What is the weight of each individual after 200 days? ___________________ 4. What was the weight of each individual after 600 days? ____________________ 5. How much weight did Individual A gain over the 600 days? ____________ Individual B? _________________________ 6. Which individual gained more weight? ___________________ 7. Which individual received the drug? _____________________ 8. What can you say about the effect of the drug on growth? _______________________________________________________ 4 7th grade review lesson key.notebook II. Cells A. Every living organism is made up of cells. In each cell, there are various organs that perform specific jobs. Match the cell parts in column A with their functions in column B. COLUMN A COLUMN B 1. Endoplasmic Reticulum A. Gives the cell its rigid shape. 2. Mitochondrion B. Fluid medium inside the cell. 3. Chloroplast C. Directs activities of the cell. 4. Vacuole D. Regulates what enters and leaves the cell. 5. Cell Membrane E. Stores cell materials. 6. Nucleus F. Produces the cells energy. 7. Cytoplasm G. Passageways that carry materials around the cell. 8. Ribosome H. Contain chemicals that break down substances. 9. Lysosome I. Structure that created proteins. 10. Cell Wall J. Captures energy from sunlight and uses it to produce food for the cell. For each situation or cell type name the cell structure needed. 11. Muscle cells need a lot of energy to move or contract. You would expect to see more ____________________ than in a nonmuscle cell. 12. Some cells function to make proteins to be sent out of a cell. You would expect to see more ____________________ than in other cells. 13. A plant cell is used to store water to help support the plant. This cell would have a large _________________. 14. Some cells in a plant are not green and are not used for photosynthesis. These plant cells have few or no ________________. 15. As a frog develops from a tadpole to an adult, its tail disappears. The ____________________ are involved in the breakdown of the tail. 5 7th grade review lesson key.notebook B. Comparing Prokaryotic and Eukaryotic Cells Prokaryotic: These cells are simple in structure, with no recognizable organelles. They have an outer cell wall that gives them shape. Just under the rigid cell wall is the more fluid cell membrane. The cytoplasm enclosed within the cell membrane does not exhibit much structure when viewed by electron microscopy. Eukaryotic: The cells of protozoa, higher plants and animals are highly structured. These cells tend to be larger than the cells of bacteria, and have developed specialized packaging and transport mechanisms that may be necessary to support their larger size. Compare prokaryotic and eukaryotic cells by completing the table below, stating “yes” or “no” for each type of cell. Cell Structure Prokaryotic Cell Eukaryotic Cell Cell Wall Cell membrane Genetic material Nucleus Mitochondria Chloroplast 6 7th grade review lesson key.notebook C. Label the following cells. 7 7th grade review lesson key.notebook D. Cell Venn Diagram Complete the Venn diagram below comparing and contrasting plant and animal cells. PLANT CELL ANIMAL CELL 8 7th grade review lesson key.notebook E. Cell Theory Fill in the blanks with information about cell theory. 1. All living things are composed of ______________. 2. Cell are the _________________ structure of living things that can perform the ____________ necessary for life. 3. Living cells come only from other ____________ _____________. 4. Cells contain __________________ information which is passed from cell to cell during cell division. 5. All cells are basically the same in _______________ composition. 6. All ___________ flow of life occurs within cells. F. Mitosis vs. Meiosis 9 7th grade review lesson key.notebook III. Cellular Organization A. Unicellular vs. multicellular organisms Classify the following descriptions as being unicellular or multicellular. 1. Has only one cell. 2. Has many cells. 3. Survives alone. 4. Individual cells cannot survive on their own. 5. Prokaryotes 6. Eukaryotes 7. Examples include amoeba, paramecium, euglena, algae, some bacteria, fungi, & yeasts. 8. Smaller, less specialized organisms 9. Division of labor of cells is specialized. 10. Examples include plants, animals, some bacteria, fungi, & yeasts. B. Levels of Organization List the levels of organization from smallest to largest by completing the table below. Identify the following examples as one of the levels of cellular organization. 1. Heart muscle 2. A group of heart muscles 3. A single heart muscle cell 4. Cardiac system C. Basic Life Functions of an Organism list the four basic life functions for all living organisms. 1. 2. 3. 4. D. Osmosis is Not a Disease Match the following vocabulary terms with their correct definitions. 10 7th grade review lesson key.notebook IV. Life Processes A. Plant & Animal Needs Classify the following statements in the Venn diagram comparing and contrasting plant and animal needs. Sunlight, Shelter, Carbon Dioxide, Water, Food/Nutrients, Oxygen, Space to Live, Soil, Stable Internal Conditions PLANT NEEDS ANIMAL NEEDS 11 7th grade review lesson key.notebook B. Fill in the Blank Use the words from the word bank below to complete each statement. 1. The process of using oxygen to turn our food into energy is called ______________. 2. The process of being born, growing, aging, and dying is called _______ _________. 3. Humans are made up of many cells, therefore, we are called __________________. 4. Humans have a stable internal condition of a temperature averaging 98.6oF. This is an example of ________________________. 5. Metabolism consists of taking in food called __________________ (when we eat we are doing this). Then the breaking down of food into simpler substances is called ______________________ (this is what our stomach does). 6. Bacteria is a singlecelled organism that reproduces by dividing in half. This is an example of ______________________ ___________________. 7. Francesco Redi proved with his simple experiment with the jars that life came from living things and there is no such thing as _______________ __________________. In the boxes below, circles yes or no if the object in the left column is able to perform the life processes. If every answer in a row is yes, the object is living. Circle the living objects. C. Stimulus vs. Response An internal or external change that causes a RESPONSE is called a STIMULUS. Write stimulus or response after each sentence for the underlined portion. 1. 2. 3. 4. 5. 6. A rabbit hides from danger. A bear hibernates in the winter. A bee is attracted to a colorful flower. A dog barks when an unknown person nears his home. A person awakes to an alarm clock. Birds migrate in the fall. 12 7th grade review lesson key.notebook V. Classification of Living Things A. Looking for Order Number the components below in order from simplest (1) to the most complex (7). _____ Species _____ Family _____ Phylum _____ Order _____ Class _____ Genus _____ Kingdom Write the mnemonic to help you remember the order of classification. K________ P________ C_________ O_________ F_________ G__________ S_________ B. Comparing Kingdoms Compare the major characteristics of the organisms in each kingdom by completing the table. Prokaryote Eukaryote Eukaryote Eukaryote Single Cell Cell wall; no other Single cell structure Nucleus, Single, Mitochondria, except for some chloroplast algae BOTH BOTH Heterotrophic Multicellular Autotrophic Multicellular Heterotrophic 13 7th grade review lesson key.notebook C. Grouping is determined by several factors. Fill in the blank for each statement. 1. Organisms are grouped based on the presence or absence of _____________ ____________ such as nucleus, mitochondria, or cell wall. 2. Does the organism have ______ cell or _______ cells. 3. How does the organism get its __________? 4. Can the organism _____________ and produce ____________ offspring? 5. Father of Classification is __________________. 6. Created _____________ ______________ two name classification system; ____________ & ______________. D. Classification Examine the table showing the classification of four organisms. Then answer the questions. 1. Which taxon includes the most specific characteristics? __________ 2. Which taxon includes the broadest characteristics? _____________ 3. Which taxon includes more species, an order or a family? ________ 4. Which taxon includes only organisms that can successfully interbreed? _______________ 5. If two organisms belong to the same family, what other taxonomic groups do the organisms have in common? _____________________ 6. Which two organisms in the chart are most closely related? ________________________ 7. To which taxa do all four organisms belong? __________________ 8. Which class does not include animals that have hair or fur? _____________________ 9. What is the order, family, and genus of a human? ________________________________ 10. Using the information in the chart, what can you conclude about the classification taxa of an organism with the scientific name Rana temporaria? ____________________________ E. Major Plant & Animal Phyla Write a brief statement about each of the phyla’s below. Only one opening radial symmetry ex. jelly fish, corals Usually unsegmented Ex. snails, slugs, clams Segmented body, soft body Blood & nervous system Ex. leeches, earthworms Segmented, invertebrate Exoskeleton of chitin Ex. crabs, spiders Nonvascular stems & leaves Roots, stems, large leaves Simple needlelike leaves Usually bares cones Ex. Pine tree Reproductive organs in flowers Symmetrical (bilateral & radial) Water vascular system Ex. Sea stars Nerve cord dorsally Ex. mammals 14 7th grade review lesson key.notebook VI. Photosynthesis A. The paragraphs below describe the process of photosynthesis in plants. Complete the description using the words from the box. Each word will be used only once. Carbon dioxide Chlorophyll Glucose Leaves Chemical energy Chloroplasts Hydrogen Light energy water Oxygen The process by which plants use __________________ from the sun to make food is called photosynthesis. This process occurs within dark green structures called ___________________, which lie within a plant’s _________________. The green pigment in the chloroplasts, called ________________, traps light energy. This light energy is changed into ________________ and stored. A plant absorbs ______________________ from the air and _______________ from the soil. The plant uses some of its stored chemical energy to split water into _________________ and oxygen. Most of the ____________________ is released into the air and is used by animals. The hydrogen and carbon dioxide combine and form a simple sugar called _________________, which the plant may store or use for energy. B. Trace the process of photosynthesis by completing the flow chart below. 15 7th grade review lesson key.notebook Complete the following formula for photosynthesis. Then balance the chemical C. equation. Carbon dioxide + _________________ _______________ + Oxygen ___________ + 6H2O # of Atoms: C: ____________ O: ____________ H: ____________ C6H12O6 + ___________ # of Atoms: C: ____________ O: ____________ H: ____________ VII. Cycles & Energy Flow A. Water Cycle Label the water cycle below using the words provided. Then answer the questions below the diagram. Word Bank Evaporation Wetland Lake Ground Water Condensation Runoff Transpiration Precipitation 1. Water vapor in the atmosphere comes from _____________________ and ____________________. 2. When water evaporates it changes from the ______________ state to the __________________ state. 3. Clouds and precipitation form when water changes from the _______________ state to the ________________ state. 4. Water enters oceans, lakes, and streams from ____________________ and _____________________. 16 7th grade review lesson key.notebook B. Carbon Cycle Answer the questions about the carbon cycle using the provided diagram. 1. In what process do organisms return carbon dioxide to the atmosphere? _______________ 2. What do you think would happen to the carbon cycle if plants were removed from the cycle? _____________ ______________________ 3. In what process do people return carbon dioxide to the atmosphere? ____________ 4. Which organism takes carbon dioxide out of the atmosphere and also returns it? ______________ C. Nitrogen Cycle Trace the flow of nitrogen through the environment by completing the flow chart. 1. What are the two ways in which plants get the nitrogen compounds they can use? ________________ ________________ 2. What is the only way a consumer can get nitrogen compounds they need? _________________________ 3. How do you think a carnivore gets the nitrogen compounds it needs? ______________________________ 4. What is the relationship between producers (plants) and bacteria in the nodules? ________________________________ ________________________________ 5. Can any organism use free nitrogen? ________________________________ 17 7th grade review lesson key.notebook D. Energy Pyramids Use the graphic below to answer the questions. Is more or less energy available in moving from 1. one energy level to the next energy level? _______________________ Where do the organisms at the lowest level get 2. their energy? ____________________ Suppose you have 1000 units of energy at the 3. lowest level (producers). Only 10% of the energy at one level can be used in the next. How many energy units are available at the second level (primary consumers)? ___________________________________ How many energy units are available at the third 4. level (secondary consumers)? _____________________ Do you think there can be an unlimited number 5. of levels? Explain. ______________________________ E. Food Webs Complete the food web by filling in the blank parts of the web using the clues. 18 7th grade review lesson key.notebook VII. Interactions in a Population A. Basic Needs of ALL Living Things: 1. 2. 3. 4. 5. B. Definitions Fill in the blanks for each definition with the correct term from the word bank. Ecosystem 1. An ________________ contains all living and nonliving things that interact in that area. Population 2. A _________________ is all the members of one species in a particular area. 3. All the different populations that live together in an area is a ___________________. Community 4. _______________ is the struggle between organisms for the limited Competition resources in a habitat. Biotic factor 5. A _______________ _______________ is a living part of an ecosystem. Abiotic factor 6. An ______________ _______________ is a nonliving part of an ecosystem. 7. An organism’s particular role in an ecosystem and how it makes its Niche living is a ________. Predator 8. A ______________ is a carnivore that hunts and kills other animals for food and has adaptations that help it to capture the animals it preys upon. Prey 9. An animal that a predator feeds upon is called ______________. 10. The relationship where both organisms benefit is called Mutualism _____________________. 11. The relationship where one organism benefits and the other is Commensalism unaffected is called ____________________. Parasitism 12. __________________ is where one organism benefits and the other is harmed. Phototropism 13. __________________ occurs when plants respond to light by growing toward it or away from it. 14. When animals respond to cold conditions with a period of lowered Hibernation metabolism is _________________. 15. _________________ occurs when organisms respond to adverse Dormancy conditions with a period of lowered or suspended metabolism. Cooperation 16. __________________ is the working together for the common good of the entire population. 17. Social order within a population to ensure that labor and resources are Social hierarchy adequately shared is _______________ _________________. 18. Leaving an organism’s mark to establish his territory is Territorial imperative ______________ _______________, which ensures that members of a population have adequate habitat to provide for basic resources. 19 7th grade review lesson key.notebook D. Order in an Ecosystem Place the following terms in order from the largest scale to the smallest. Niche, population, ecosystem, species, community, habitat 20 7th grade review lesson key.notebook IX. Interactions in an Ecosystem A. Interactions among living things Complete the concept map showing the ways in which living things interact. WORD BANK Competition Commensalism Predation Mutualism Predator Parasitism B. PredatorPrey Relationships Use the data table to answer the questions below. 1. How many moose were there in 1963? _______ How many wolves were there in 1963? _______ 2. Describe the change in the moose population 3. from 1963 to 1977. ____________________________ Describe the change in the wolf population from 4. 1963 to 1977. ________________________________ Why do you think the moose population grew 5. during that time frame? ________________________ Why do you think the wolf population 6. eventually started to increase? ___________________________________ What happened to the moose population 7. starting in 1973? ____________________________ Why do you think this happened? ___________ 8. ____________________________________________ If the wolf population continues to decline, 9. would the moose population increase right away? ______________ Might it start to increase several years later? __________ 10. What other factors other than the predatorprey relationship may effect these two populations? _____ ____________________________________________ 21 7th grade review lesson key.notebook C. Organisms in an Ecosystem Complete the concept map below using the provided word bank. WORD BANK Scavengers Producers Herbivores Decomposers Omnivores Consumers Carnivores Eat other organisms D. Symbiotic Relationships Classify the following examples as mutualism, commensalism, or parasitism. Mutualism: Relationship that benefits both organisms. Commensalism: Relationship that benefits one organism and the other is not helped or harmed. Parasitism: Relationship that benefits one organism and harms the other. 1. Bacteria living inside a termite’s digestive system breaks down wood into a material the termite can digest. The bacteria gets food and a place to live, the termite gets food. _____________________ 2. Head lice living on a human scalp. _______________________ 3. A remora (a fish) swims with a shark. The remora eats bits of food that escape the shark’s mouth as they float by. The shark is neither helped nor harmed by the remora. _________________ 4. A small fish swims with a larger fish. The small fish eats organisms living on the skin of the larger fish. ______________________ 5. A bird building their nest in a tree. ___________________ 6. A tick attaches itself to the skin of a deer. The tick gets food and shelter. The deer is harmed by loss of blood. ______________________ 22 7th grade review lesson key.notebook X. Adaptation in an Ecosystem A. Biome vs. Ecosystem Fill in the blanks for the following systems using the words biome and ecosystem. 1. A group of ecosystems with similar climates and organisms is called a ___________. 2. All the living and nonliving things that interact in a particular area is called an ______________________. 3. The difference between a biome and an ecosystem is…… a. A ____________ is larger and contains one or more _________________. b. An ________________ is smaller than a ___________ and is located within a ______________. B. Terrestrial vs. Aquatic Biomes Classify the following biomes as being either a terrestrial (land) biome or an aquatic (water) biome. 23 7th grade review lesson key.notebook C. Biotic vs. Abiotic Factors Complete the chart below, then identify the following examples as being either a biotic factor or an abiotic factor. 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. Grass Water Rocks Bacteria Fungi Sunlight Oxygen Soil Birds Tree D. Adaptations State how the following organisms have adapted to their ecosystems. 1. What is one adaptation that a camel has that allows it to survive in the desert? Hump that stores fat and water so it can go a long time without water. 2. How are the mouths of pythons adapted to finding prey and swallowing large prey? Senses prey with tongue and mouth unhinges to open for large prey. 3. How are giraffes long necks adapted to their lifestyle? Allows them to reach leaves higher up on the trees. 4. What adaptations do polar bears have that allow them to survive in the arctic? White fur, insulated by fur and fat for cold temps. 5. What adaptations do mountain goats have that allow for living in the tops of high, cold mountains? Surefooted hooves, light weight, and thick fur. 24 7th grade review lesson key.notebook XI. Ecosystems and Biomes Change Over Time A. Daily vs. Seasonal Responses Define the following terms and then state if they are daily responses or seasonal responses. 1. Nocturnal: Active only at night, sleep during the day daily response 2. Hibernation: Body activity is reduced to minimum required for survival seasonal response 3. Diurnal: Active only during the day, sleeps at night daily response 4. Phototropism: Plants that grow towards or away from sun daily response 5. Dormancy: Organisms respond to adverse conditions with a period of lowered/suspended metabolism seasonal response B. Limiting Factors Any event that can increase or decrease the population size. Determine what will happen to various populations given the following situations. 1. There is an increase in food. ____________________________________ 2. There is a decrease in food. ____________________________________ 3. A new predator moves into the area. _____________________________ 4. There is a decrease in predators. ________________________________ 5. There is a volcano eruption. ____________________________________ C. Ecological Succession The natural process, following a disturbance, in which one community of plants and animals gradually replaces another in response to changing environmental conditions. Use the graphic to answer the questions below. 1. What is the main difference between the first stage and the last stage? ______________________________________________________________ 2. Approximately how long does it take to reach the mature forest stage? _____________ 3. Which stage has the greatest diversity of animals? ______________________________ 4. What could happen to the mature forest that would cause this succession to start over again? _____________________________________ 5. In which stage of the succession would you find large mammals, such as bear or deer? ________________________________________________ 6. In which stage of the succession would you find small mammals, such a squirrels or rabbits? ______________________________________________ 25 7th grade review lesson key.notebook XII. Relationships Between Ecosystem Dynamics and Human Activity A. Ecosystems are dynamic Answer the following questions for each situation. 1. The environment determines the boundaries of an ecosystem. Any change to the environment changes the ecosystem. What are some of the changes that could change the ecosystem? ____________________________ _______________________________________________________________ 2. Ecosystems are dynamic (changing) systems in which there is constant movement of energy and materials. However, within the flow of energy, environmental resources and organisms tend to be in balance. For example, if humans harvest too much of the available resources, what will happen to the consumers of that ecosystem? __________________________________ 3. Human activities are a major cause of extinction due to habitat destruction. What are some examples of habitat destruction? _____________ _______________________________________________________________ 4. Another human activity that breaks larger habitats into smaller ones is called habitat fragmentation. What are some examples of habitat fragmentation? __________________________________________________ ______________________________ B. Protecting Biodiversity List three ways in which humans are protecting biodiversity and what they do to protect. 1. _____________________________________________________________ 2. _____________________________________________________________ 3. _____________________________________________________________ 26 7th grade review lesson key.notebook XIII. Genetics A. Vocabulary Use the word bank below to fill in the blanks. 1. _______________ genes are written with a capital letter. 2. An organism’s physical appearance is called its __________________. 3. The scientist who founded genetics by studying pea plants is ____________ ________________. 4. The make up of the organism’s genes, dominant and recessive, is called ____________. 5. The “weaker” trait is called the __________________ gene. 6. “Factors” inherited by each parent are called ______________. B. Punnet Square Look at the punnet square to the right. Use the example to complete the square below. 27 7th grade review lesson key.notebook 28 7th grade review lesson key.notebook C. Phenotype vs. Genotype Classify the following examples as phenotype or genotype. 1. LL 2. Yellow body 3. Round eyes 4. Rr 5. yy 6. Oval eyes 7. Yy 8. Stubby nose 9. Blue body 10. ss 11. Roundpants 12. RR D. Genetic Engineering Use the words below to fill in the blanks. Recombinant DNA Inbreeding Cloning Hybridization Gene Therapy Selective Breeding 1. Creating an organism from the genes of another organism resulting in an exact copy of the original organism is called ____________________. 2. The crossing of two individuals that have identical or similar sets of alleles is called ________________. 3. ______________ _________ is the process of using plasmid of bacteria which is cut to allow human DNA to be inserted into it and then put back into the bacteria. 4. ___________ ___________ is the process of inserting working copies of a gene directly into the cells of a person with a genetic disorder. 5. Crossing two individuals with desired traits to serve as parents to the next generation is called _______________ _________________. 6. ___________________ is the crossing of two genetically different individuals. 29 7th grade review lesson key.notebook XIV. Evolution A. Theory of Evolution The father of evolution is ________________ ________________. • His theory is based off ______________ ______________, which is • the process by which individuals that are better adapted to their environment are more likely to survive and reproduce than other members of the same species. B. Evolution The gradual change in a species over time is called ______________. • Offspring can show variations even though they have the same set of • parents. These changes can take place through a related set of processes that include: ___________________ changes in the chromosome or gene which o can be passed from generation to generation. ___________________ characteristics that slowly develop over a o long period of time that helps an organism survive in its environment or reproduce. _____________ ____________ “survival of the fittest.” Over a long o period of time helpful variations gradually accumulate in a species, while unfavorable ones disappear. ___________________ A species that has no living members. o C. Environmental Changes in Evolution Environmental changes that can bring about changes in a species • include: ______________ ___________ this creates geographic isolation and o is one of the main ways that new species are formed. _____________________ o _____________________ o ______________________ o ______________________ o ______________________ drastic reduction in rain changes the o type of food source available to organisms. Animals will experience adaptation to the new food source or die. D. Fossils Fossils are preserved remains or traces of an organism that lived in • the past. They are formed with organisms die and become buried in sediment. The age of a fossil can be determined by relative dating or absolute • dating. _______________ dating determines which of two fossils is the o oldest. _______________ dating determines the actual age of fossils. o E. Evidence of Evolution There are several sources that can be used as evidence for evolution. • They include: __________________ ______________ o __________________ ______________ different organisms with o similar bone structures that are used for different functions. __________________ similarities during the earliest stages of o development. __________________ _____ _________ o 30 7th grade review lesson key.notebook 31