Which of the following kinds of organisms are best adapted to habitats that are frequently subject to unpredictable and severe environmental fluctuations?
(A) organisms with very specific diets
(B) ectothermic organisms
(C) top predators
(D) keystone species
(E) r-selected organisms
Of the following, which is an example of a mutualistic relationship?
(A) the protozoan Trichonympha digesting wood in the gut of a termite
(B) the sporozoan Plasmodium reproducing in human blood cells and liberating toxins into the human body
(C) two species of Paramecium deriving food from a common laboratory culture
(D) rabbits being eaten by foxes
(E) humans inadvertently providing food for cockroaches
Deposits of coal in Greenland and the Antarctic indicate that
(A) these regions once contained numerous mollusks that deposited carbohydrates in their shells
(B) the Earth’s crust in these regions contains vast amounts of limestone
(C) these regions were once thickly vegetated
(D) there is a rich store of dissolved carbon dioxide in the seas surrounding these regions
(E) a geologic uplift of coral rock and ocean bed has recently occurred in these regions
If poorly drained soils encourage the growth of bacteria that convert nitrate to nitrogen, the effect on higher plants will be to
(A) increase lipid production
(B) decrease protein production
(C) increase carbohydrate production
(D) produce unusually large fruits
(E) stimulate chlorophyll production
Which of the following statements best describes the movement of energy in an ecosystem?
(A) radiant energy is converted into chemical energy in plant photosynthesis and then released as heat energy during cellular respiration
(B) energy cycles within an ecosystem
(C) plants get energy from the nutrients in the soil
(D) the animals in an ecosystem absorb the radiant energy of the sun and use it to make organic molecules such as proteins
(E) some chemoautotrophic bacteria release energy that can then be used by soil animals to make food
Mistletoe is attached to the branches of trees such as sweet gum, from which it obtains water and some nutrients.
Due to this association, tree growth may be diminished. Which of the following terms describes the relationship between the two plants?
(A) commensalism
(B) competition
(C) mutualism
(D) parasitism
(E) predation
Which of the following best explains why a pictorial presentation of the biomass at each trophic level of an ecosystem is a pyramid?
(A) the loss of iron from an ecosystem
(B) the amount of energy passed from one trophic level to the next
(C) the number of predators in the ecosystem
(D) the chemical compounds in an ecosystem are recycled
(E) the average size of the individuals in each species
A katydid is an insect. Its leaf-like appearance is an example of
(A) cryptic coloration
(B) aposematic coloration
(C) Müllerian mimicry
(D) agonistic behavior
(E) Batesian mimicry
Which of the following biomes typically has the greatest annual precipitation?
(A) temperate deciduous forest
(B) taiga
(C) savanna
(D) tropical rain forest
(E) prairie
Plants that live in the tundra are likely to have which of the following adaptations?
(A) tall, single shoots
(B) broad, light-colored leaves
(C) cones that are fire adapted
(D) an association with epiphytes
(E) shallow root systems
A species of malaria-carrying mosquito lives in a forest in which two species of monkeys, A and B, coexist. Species A is immune to malaria, but species B is not. The malaria-carrying mosquito is the chief food for a particular kind of bird in the forest. If all of these birds are eliminated suddenly, which of the following would be the immediate observable consequence?
(A) increased mortality in monkey species A
(B) increased mortality in monkey species B
(C) increased mortality in the malaria-carrying mosquitoes
(D) emergence of malaria-resistant strains in monkey species B
(E) emergence of malaria-sensitive strains in monkey species A
The most probable explanation for the relative masses of the first- and second-order consumers is that (pic31)
(A) each link in the food chain of an ecosystem has less available energy than the previous link has
(B) only a small fraction of sunlight that reaches the Earth is transformed into chemical energy by photosynthesis
(C) the total energy of the decomposers is greater than that of the rest of the organisms put together
(D) seasonal fluctuations in weather limit the number of consumers
(E) second-order consumers require more total energy than first-order consumers do
If the lake is assumed to be a typical ecosystem, the percent of radiant energy from the Sun reaching the lake that is trapped in photosynthesis is about (pic32)
(A) 100%
(B) 10%
(C) 1%
(D) 0.1%
(E) 0.01%
A population of crayfish exhibits wide variation in body size, which is a heritable trait. A species of fish that preys on crayfish has been introduced to the population, but the fish can only eat small crayfish. Which of the following is a likely prediction about the population of crayfish in the presence of the predator?
(A) The crayfish will evolve new antipredator behaviors.
(B) The crayfish diet will shift to avoid competition with the fish.
(C) The population will have a smaller average body size owing to stabilizing selection.
(D) The population will have a larger average body size owing to directional selection.
(E) The population will experience disruptive selection, resulting in two distinct size classes of crayfish.
Which of the following are producers in an aquatic food chain?
(A) Crustaceans
(B) Algae
(C) Insects
(D) Fungi
(E) Trout
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