7. Question #1: Besides temperature, what other abiotic factor greatly affects the amount of dissolved oxygen in a body of water? A. growth rate of populations B. size of soil particles C. length of light period D. number of fish species Question #2: Why is it important for organisms to respond to external environmental factors? A. to maintain homeostasis B. to increase tolerance of environmental extremes C. to adapt to their environment D. to accelerate the process of natural selection

12. Question #1: Bacteria decompose dead matter by: A. carrying out photosynthesis. B. going through binary fission. C. using plant & animal material as food. D. reproducing rapidly. Question #2: How can viruses be treated medically to reduce their numbers & prevent them from spreading? A. Use antibiotics to kill them & use vaccines to prevent them from spreading. B. Use vaccines to kill them & use antibiotics to prevent them from spreading. C. Prevent them from spreading using vaccines, but do not treat them with antibiotics. D. Prevent them from spreading using antibiotics, but do not treat them with vaccines.

15. Question #1: A volcanic eruption devastates an area directly southeast of a volcano. Which of the following organisms would be the first to grow in this area? A. a shrubby bush B. a hardwood tree C. a climbing vine D. a lichen Question #2: What term refers to the final stage of a forest’s development? A. pioneer species B. secondary forest C. climax community D. conifer forest

22. Question #1: When two organisms in a mutualistic relationship are physically separated, which of the following will most likely occur? A. both organisms will become parasites B. one organism will consume the other organism C. one organism will benefit, but the other will die D. both organisms’ chances of survival will be reduced

23. Question #2: The roots of a mistletoe plant absorb nutrients from living oak trees causing some damage to the tissues of the trees. This is an example of: A. mutualism. B. commensalism. C. parasitism. D. saprophytism.

26. Question #1: Why are there more plant & animal species in tropical rainforests than in deserts? A. because there is more available water in tropical rainforests B. because there is too much sand in deserts C. because there is more carbon dioxide in desert atmospheres D. because there is more sunlight in tropical rainforests Question #2: A lichen results from an interaction between two organisms, a fungus & an alga. The alga supplies food, while the fungus traps water & keeps the alga moist. This is an example of which of the following? A. commensalism B. mutualism C. parasitism D. predation

35. 10%

36. 90%

37. Question #1: If an ecosystem contains 100 units of energy at the producer trophic level, then it will most likely contain about how many units of energy at the secondary consumer level? A. 1 B. 10 C. 100 D. 1,000

38. Question #2: Study the above illustration of a food web. What would happen if coyotes were removed from the ecosystem? A. The population of hawks & snakes would decrease. B. The population of grasses & shrubs would greatly increase. C. The rabbit & rat population would greatly decrease. D. The rabbit & rat population would increase.

40. Question #1: The desert tortoise feeds on prickly pear cactus & other desert plants. Which of these best describes the desert tortoise in this desert community food web? A. the desert tortoise is a herbivore B. the desert tortoise is a producer C. the desert tortoise is a predator D. the desert tortoise is a carnivore

42. Question #1: Some marine organisms participate in the carbon cycle by using dissolved carbon dioxide in photosynthesis. This process is accompanied by which energy change? A. solar energy being destroyed B. solar energy being transformed into matter C. solar energy being split into its component parts D. solar energy being transformed into chemical energy

43. Question #2: All of the organisms in a typical ecosystem are interdependent, helping to maintain the equilibrium of the ecosystem & sustaining each other. Which of the following processes can bacteria perform that is not possible for the other members of a typical ecosystem? A. converting radiant energy into chemical energy B. conserving water C. using nitrogen from the atmosphere D. decomposing the remains of dead organisms

45. Question #1: A person living near this pond wants to reduce the mosquito population. The mosquito population in this ecosystem could be reduced by: A. planting more duckweed. B. catching more minnows. C. removing some martin houses. D. adding more shelter for frogs.