1. Living things are formed from carbon-containing molecules, so the carbon cycle is the only biogeochemical cycle that really affects humans.

Transcription

1 hapter 2 Test True/False Indicate whether the statement is true or false. 1. Living things are formed from carbon-containing molecules, so the carbon cycle is the only biogeochemical cycle that really affects humans. 2. Some plants have bacteria living in nodules on their roots that fix atmospheric nitrogen, converting it to a form of nitrogen the plant can use. ecause living organisms (bacteria) are involved in the process, nitrogen availability is a biotic factor for the plant. 3. The biotic factors that affect an organism include other species in that organism s community. 4. Large volumes of atmospheric dust, such as those from massive volcanic eruptions, do not affect food webs because they do not affect the energy output of the Sun, the ultimate source of energy for food webs. 5. Even though you need sunlight for some body processes, such as synthesizing vitamin, you have to eat a producer to use solar energy for respiration and movement. Modified True/False Indicate whether the statement is true or false. If false, change the identified word or phrase to make the statement true. 6. bird fluffs its feathers to trap warm air close to its body. The temperature of the air next to the bird s skin is a(n) abiotic factor. _ 7. Photosynthetic autotrophs remove water from the air as part of one of the major biogeochemical cycles. _ 8. Sunlight is the ultimate energy source driving the biogeochemical cycles. _ 9. green plant is wrapped in an airtight plastic bag and placed in sunlight for one hour. The oxygen level of the air inside the bag will increase during that time. _ 10. researcher is interested in plants and nitrogen. She puts two groups of plants into identical soil that has been sterilized, so there are no living organisms in it. One group of plants is placed in a chamber with ordinary air, and the other group is placed in a chamber with air that has been enriched with nitrogen gas. The two groups of plants will grow at identical rates. _ Multiple hoice Identify the choice that best completes the statement or answers the question. 11. Some birds are known as honey guides because they may be followed by humans to wild beehives. When the humans take honey from the hives, the birds are able to feast on the honey and bees, too. This type of relationship can best be described as. a. parasitism c. mutualism b. commensalism d. symbiosis

2 12. ougars are predators that often eat weakened or diseased animals. This is a description of the of cougars. a. habitat c. niche b. community d. none of these Figure Referring to Figure 2-1, suppose 10, 000 units of energy are available at the level of the grasses. What is the total number of energy units available by the time energy reaches the coyote? a. 10 units c. 100 units b. 990 units d units 14. Referring to Figure 2-1, the cat would be considered. a. herbivores c. second-level consumers b. third-level consumers d. decomposers Figure The group of animals in Figure 2-2 is an example of what? a. community c. population b. ecosystem d. biosphere

3 Figure In the energy pyramid shown in Figure 2-3, which level has the largest number of organisms? a. fox c. grasshoppers b. birds d. grass 17. Which of the following is the ultimate source of energy for the pyramid in Figure 2-3? a. grass c. sunlight b. heat d. water flea Figure The organism shown in Figure 2-4 is involved in which type of symbiosis? a. mutualism c. parasitism b. commensalism d. predation

4 19. Which of the following information could be included in the description of a grasshopper s niche, but not in a description of its habitat? a. continent where it lives c. plant species it eats b. locations where it shelters d. temperatures it experiences 20. Organisms with overlapping niches probably have which type of relationship? a. commensal c. mutualistic b. competitive d. parasitic 21. What is dissolved oxygen in water to an earthworm? a. abiotic factor c. biotic factor b. biome d. carbon source 22. How long are food chains? a. four steps long c. it varies with day length b. three steps long d. it varies with ecosystem Figure The graph in Figure 2-5 is probably showing which of the following? a. number of species present in a community at each of three trophic levels b. number of food chains that can be drawn from the same food web c. amount of evergy at three trophic levels in a particular community d. number of abiotic factors affecting three species in the same community 24. Which of the following would be the easiest way to diagram predatory and parasitic relationships between several species? a. biomass pyramid c. food web b. food chain d. numbers pyramid 25. Which process describes nitrogen fixation?

5 a. animals eat plants containing nitrogen and return it to the soil through urination b. bacteria take nitrogen from the air and convert it to a form usable by plants c. organisms die and are decomposed into ammonia in the soil d. plants take nitrogen from the air and store it in their roots 26. Your favorite plant is growing very slowly, and you would like to find some way to increase its growth rate. Which of the following should you try increasing first? a. nitrogen c. sodium b. oxygen d. calcium 27. Some farmers use manure on their crop fields. How does this help the plants? a. protects them from intense sunlight b. keeps insects from eating the crops c. increases soil nitrogen and phosphorus levels d. increases soil oxygen and carbon dioxide levels 28. Which of the following allows the flow of energy through an ecosystem to happen? a. abiotic factors c. evaporation b. cycling of nutrients d. predation 29. Which location would most likely hold autotrophs that derive their energy from chemical compounds? a. swamp sediments c. grassland soil surface b. antarctic pools d. desert rocks 30. One of the nutrient cycles moves from an atmospheric gaseous form to the soil through both abiotic and biotic processes, moves through the food web, then is returned to the soil or to the atmosphere. Which cycle fits this description? a. carbon c. phosphorus b. nitrogen d. water ompletion omplete each statement. 31. Water, carbon, and nitrogen are released back into the atmosphere during. 32. To explain and show how the amount of living material at each trophic level of a food chain changes, you could use a pyramid of. 33. Mosquito larvae are eaten by some fish species when they are present in the same body of water. For the mosquito these fish are a factor. 34. urning fossil fuels has rapidly released long-term reserves of the cycle. 35. dding carbon dioxide to a greenhouse generally increases the rate of plant growth meaning that in natural concentrations it the growth of plants. 36. The relationship between nitrogen-fixing bacteria and their host plants is best called. 37. ecomposers recycle from other organisms, but they use energy to do so.

6 38. nitrogen molecule has just been fixed by a nitrogen-fixing bacterium. The next organism to use the nitrogen molecule is probably a(n). Short nswer 39. ompare and contrast the ways carbon and water cycle through the biosphere. Figure Use the diagram in Figure 2-6 to complete Table 2-1. lassify each member of the food web as autotroph or heterotroph, and identify the heterotrophs as herbivores, carnivores, or omnivores. Table 2-1 utotrophs Heterotrophs Herbivore, carnivore, or omnivore 41. When a grouse (a type of bird) eats berries, the berry seeds are eliminated as waste materials and may be dropped in another part of the forest where they may sprout and eventually grow into new berry plants. How would you classify the relationship between the berry plant and the grouse? Explain your reasoning. 42. Ecologists study the attributes of a biological community to learn about how it works. These attributes include the number of species and the number of different kinds of species interactions. What attributes would an ecologist study about a population to understand it? Problem scientist wrote the following summary of her observations:

7 Milkweed is a plant commonly found throughout fields and pastures and along roadsides in eastern and central North merica. It gets its name from the milky white sap that oozes when the plant is broken or cut. Milkweed plants bloom in June and July. When fertilized, the flowers form large seedpods that open in the fall. The following observations were taken from a scientist's field study of milkweed plants from spring through fall. In the summer, the sugary nectar secreted by the milkweed's flowers attracts many bees, butterflies, moths, and a variety of smaller insects that carry away pollen when they depart. Milkweed nectar seems to be the major source of nutrition for several species of small moths, flies, mosquitoes, and ants. Monarch butterflies, which visit in large numbers, lay their eggs on milkweed plants, and the hatching caterpillars feed on the leaves. s fall approaches, milkweed bugs begin to attack the developing seeds, and milkweed beetles eat the foliage. phids, which suck milkweed sap, are found throughout the year. rab spiders do not feed on the plant itself, but rather on most of the insects that visit the plant. In the two to three weeks while the milkweed plants are in bloom, successful adult female crab spiders may increase ten times in mass before laying their eggs on the inner surface of leaves. Some species of flies and wasps, which feed on crab spider eggs, visit the plants periodically. Harvestmen, also known as "daddy longlegs," recover the remains left by predators. 43. How would you describe the symbiotic relationship between the milkweed plant and aphids? 44. ased on the scientist's observations, what is one food chain that begins with a milkweed plant?

8 hapter 2 Test nswer Section TRUE/FLSE 1. NS: F Nitrogen, phosphorus, oxygen, and water all play critical roles for organisms. PTS: 1 IF: loom's Level F REF: NT: LS_4a ST: III.5.5 TOP: NS: F Physical factors such as nitrogen availability are abiotic regardless of the processes that regulate them. PTS: 1 IF: loom's Level E REF: NT: LS_4a ST: III.5.1 TOP: NS: T iotic factors include all living things that interact with an organism in its habitat. PTS: 1 IF: loom's Level REF: NT: LS_4c ST: III.5.1 TOP: NS: F The dust does not affect the output of the Sun, but it does affect the amount of energy reaching photosynthetic organisms, and, therefore, food webs. PTS: 1 IF: loom's Level E REF: NT: LS_5b ST: III.5.4 TOP: NS: T Sunlight causes physiological changes in humans, but humans and other consumers cannot photosynthesize. PTS: 1 IF: loom's Level REF: 41 NT: LS_4b ST: III.5.2 TOP: 2-5 MOIFIE TRUE/FLSE 6. NS: T Physical factors like temperature are abiotic. PTS: 1 IF: loom's Level REF: 35 NT: LS_5d ST: III.5.1 TOP: NS: F carbon utotrophs release water to the atmosphere through transpiration. They remove carbon from the atmosphere during photosynthesis. PTS: 1 IF: loom's Level E REF: 47 NT: LS_4a ST: III.5.5 TOP: NS: T Through both biotic and abiotic processes, sunlight provides the energy for nutrient cycles.

9 PTS: 1 IF: loom's Level E REF: NT: LS_4a ST: III.5.2 TOP: NS: T photosynthesizing plant converts carbon dioxide from the air to carbohydrates, releasing oxygen. PTS: 1 IF: loom's Level REF: 47 NT: LS_1e TOP: NS: T Nitrogen is a limiting factor for plant growth, but it has to be added to the soil in the form of nitrates. acteria that would fix atmospheric nitrogen, making it available to the plants, are removed from the experiment when the soil is sterilized. PTS: 1 IF: loom's Level F REF: 48 NT: LS_5e ST: III.5.4 TOP: 2-9 MULTIPLE HOIE 11. NS: oth the bird and the human benefit from the relationship. heck page 40 for the definition of parasitism. oth the bird and the human benefit. an you tell anything more specific about who benefits from the relationship? PTS: 1 IF: loom's Level REF: NT: LS_4c ST: III.5.5 TOP: NS: The role the cougar plays in the ecosystem, and the relationships it has with other animals, is part of its niche. You're on the right track. What's the definition of a community? Look at page 38 for a clue. PTS: 1 IF: loom's Level REF: 38 NT: LS_5e ST: III.5.1 TOP: NS: 9000 units are lost between the grass and the mouse, 900 between the mouse and the cat, and 90 between the cat and the coyote. How much energy is transferred between the grass and the mouse? Review the pyramid model on page 44. You're on the right track.

10 PTS: 1 IF: loom's Level E REF: NT: LS_5f ST: III.5.2 TOP: NS: The mouse is a herbivore, or first-level consumer. The cat is a second-level consumer and the coyote is a third-level consumer. herbivore is a first-level consumer. You're on the right track. What are examples of decomposers? PTS: 1 IF: loom's Level REF: NT: LS_4b ST: III.5.2 TOP: NS: group of animals of the same species is a population. Review the definition of a community. n ecosystem includes abiotic factors. How big is the biosphere? PTS: 1 IF: loom's Level REF: ST: III.5.2 TOP: NS: The fox-containing trophic level, at the top, will have both the smallest biomass and the smallest number of individuals. You're on the right track. Where are the grasshoppers on the diagram? Try counting the blades of grass. PTS: 1 IF: loom's Level REF: 44 NT: LS_5f ST: III.5.1 TOP: NS: The Sun provides the ultimate source of energy for all food chains based on photosynthetic producers. Where does the grass get its energy? You're on the right track. Water is a nutrient. PTS: 1 IF: loom's Level REF: NT: LS_5b ST: III.5.2 TOP: 2-5

11 18. NS: Fleas benefit from their hosts (mammals), but the hosts experience negative effects. This is a parasitic relationship. Who benefits from this relationship? ommensalism means one member of the relationship is neither helped nor harmed. Review the definition of a predator on page 38. PTS: 1 IF: loom's Level REF: NT: LS_4c ST: III.5.2 TOP: NS: The habitat description for an organism includes all the physical factors of its environment, but the relationships it has with other species are part of its niche. heck page 38 for clues. What is the definition of habitat? full description of the habitat could include temperature ranges. PTS: 1 IF: loom's Level REF: 38 NT: LS_5e ST: III.5.1 TOP: NS: ompetition is most intense when organisms are competing for the same resources, and organisms with similar niches rely on the same resources by definition. o commensal organisms eat the same things? heck the definition of mutualism. id you consider all the factors? PTS: 1 IF: loom's Level E REF: NT: LS_4c ST: III.5.1 TOP: NS: Soil type is a physical characteristic that impacts the earthworm. biome is a group of ecosystems. You're on the right track. heck the carbon-cycle reservoirs on page 47. PTS: 1 IF: loom's Level E REF: NT: LS_5e ST: III.5.1 TOP: NS: Food chains are of various lengths and each food web contains food chains of differing lengths.

12 o all ecosystems have only four trophic levels? Food chains do not have a fixed length. aylength does not have a direct effect on food chain length. That's right! PTS: 1 IF: loom's Level F REF: 43 NT: LS_4b TOP: NS: The amount of biomass decreases as trophic level increases. What would level = 2 and y = 3 represent? You're on the right track. It's not very likely that three species would be affected by such small numbers of abiotic factors. PTS: 1 IF: loom's Level REF: 44 NT: LS_5f ST: III.5.2 TOP: NS: food web is the only one of these four methods that would allow a detailed and accurate representation of several different types of relationships. How would you show the difference between predation and parasitism? You're on the right track. Review the numbers pyramid on page 44. PTS: 1 IF: loom's Level F REF: NT: LS_4b ST: III.5.2 TOP: NS: Nitrogen fixation is performed by specialized bacteria that convert nitrogen gas into ammonia. This happens during the nitrogen cycle, but it is not called fixation. heck page 48. You're on the right track. PTS: 1 IF: loom's Level REF: 48 NT: LS_4a ST: III.5.5 TOP: NS: Nitrogen is a limiting factor for plants and farmers often add nitrogen in the form of fertilizer to increase plant growth rate.

13 Oxygen is readily available in the atmosphere. Sodium is not a limiting nutrient. Is calcium usually a limiting nutrient? PTS: 1 IF: loom's Level E REF: NT: LS_5e ST: III.5.5 TOP: NS: Manure is a natural fertilizer that releases nutrients into the soil. Nitrogen and phosphorus are especially useful to plants. The manure lies on the soil, at the base of the plants. o you think insects would stay away from manure? You're on the right track. PTS: 1 IF: loom's Level REF: NT: LS_5e ST: III.5.5 TOP: NS: Predator/prey interactions are an important process for transferring energy from one trophic level to the next. How is energy transferred between trophic levels? Matter is recycled, but energy flows in one direction only. Review the section on food webs. PTS: 1 IF: loom's Level REF: 43 NT: LS_4b ST: III.5.2 TOP: NS: utotrophs using chemical energy are found where light is not available, such as within swamp sediments or deep ocean thermal vents. That's right! These are exposed to sunlight and so will contain photoautotrophs. There is plenty of sunlight here, so photoautotrophs will be present. onsider a location where light is absent. PTS: 1 IF: loom's Level F REF: 41 TOP: NS: Nitrogen is the only nutrient that goes into the soil through both biotic (nitrogen-fixing bacteria) and abiotic (lightning) processes. arbon dioxide is taken up by plants directly from the atmosphere.

14 Review the phosphorus cycle on page 49. How does water get out of the atmosphere? PTS: 1 IF: loom's Level REF: NT: LS_4a ST: III.5.5 TOP: 2-9 OMPLETION 31. NS: decomposition This process plays a key role in all the biogeochemical cycles. PTS: 1 IF: loom's Level E REF: NT: LS_4a ST: III.5.5 TOP: NS: biomass iomass at each trophic level of a food chain is related in a predictable way. PTS: 1 IF: loom's Level REF: 44 NT: LS_5f ST: III.5.2 TOP: NS: biotic iotic factors are living things that affect an organism ecologically. PTS: 1 IF: loom's Level REF: 35 NT: LS_4c ST: III.5.1 TOP: NS: carbon Petroleum and coal are long-term storage reserves of carbon that are being released rapidly by burning them. PTS: 1 IF: loom's Level REF: 47 NT: LS_4a LS_4e ST: III.5.5 TOP: NS: limits When an added amount of a nutrient increases growth, that nutrient is considered a limiting factor. PTS: 1 IF: loom's Level E REF: NT: LS_4e ST: III.5.5 TOP: NS: mutualism The plants benefit from increased nitrogen availability, and the bacteria benefit because they can use some of the sugars the plants produce through photosynthesis. PTS: 1 IF: loom's Level E REF: NT: LS_4c ST: III.5.1 TOP: NS: nutrients ecomposition breaks down organic material, releasing nutrients back into an ecosystem.

15 PTS: 1 IF: loom's Level REF: 42 NT: LS_4b ST: III.5.2 TOP: NS: plant Nitrogen-fixing bacteria often live in close association with plants, who benefit from the usable nitrogenous compounds the bacteria produce. PTS: 1 IF: loom's Level REF: 48 NT: LS_4a ST: III.5.5 TOP: 2-7 SHORT NSWER 39. NS: nswers will vary but should include that both carbon and water are found together in the biotic parts of the biosphere. The major reservoir for carbon is the atmosphere and oceans, while the major reservoir for water is the oceans. Students may describe or draw the water and carbon cycles. PTS: 1 IF: loom's Level REF: NT: LS_4a ST: III.5.5 TOP: NS: Table 2-1 utotrophs Heterotrophs Herbivore, carnivore, or omnivore seeds grasshopper herbivore berries elk herbivore grasses marmot herbivore chipmunk herbivore grouse omnivore grizzly bear omnivore goshawk carnivore PTS: 1 IF: loom's Level REF: NT: LS_4b ST: III.5.2 TOP: NS: The relationship is one of mutualism as the grouse benefits by getting food energy from the berries and the berry plant benefits by having its seeds dispersed; thus, its reproduction is aided. PTS: 1 IF: loom's Level REF: NT: LS_4c ST: III.5.1 TOP: NS: nswers will vary. ttributes of a population include its size, growth rate, and distribution or range. PTS: 1 IF: loom's Level E REF: NT: LS_4d TOP: 2-2 PROLEM

16 43. NS: The aphids are parasites. PTS: 1 IF: loom's Level REF: NT: LS_4c ST: III.5.1 TOP: NS: nswers may vary. Milkweed-mosquito-crab spider-harvestman. PTS: 1 IF: loom's Level REF: 43 NT: LS_4b ST: III.5.2 TOP: 2-6