The three basic variables that make up the life history of an organism are

The three basic variables that make up the life history of an organism are

A) life expectancy, birth rate, and death rate.
B) number of reproductive females in the population, age structure of the population, and life expectancy.
C) age when reproduction begins, how often reproduction occurs, and how many offspring are produced per reproductive episode.
D) how often reproduction occurs, life expectancy of females in the population, and number of offspring per reproductive episode.
E) the number of reproductive females in the population, how often reproduction occurs, and death rate.



Answer: C

Natural selection involves energetic trade-offs between

Natural selection involves energetic trade-offs between

A) choosing how many offspring to produce over the course of a lifetime and how long to live.
B) producing large numbers of gametes when employing internal fertilization versus fewer numbers of gametes when employing external fertilization.
C) the emigration of individuals when they are no longer reproductively capable or committing suicide.
D) increasing the number of individuals produced during each reproductive episode with a corresponding decrease in parental care.
E) high survival rates of offspring and the cost of parental care.



Answer: E

Which of the following can contribute to density-dependent regulation of populations?

Which of the following can contribute to density-dependent regulation of populations?

A) the removal of toxic waste by decomposers
B) intraspecific competition for nutrients
C) earthquakes
D) floods
E) weather catastrophes



Answer: B

Which of the following is an example of Batesian mimicry?

Which of the following is an example of Batesian mimicry?

A) an insect that resembles a twig
B) a butterfly that resembles a leaf
C) a nonvenomous snake that looks like a venomous snake
D) a fawn with fur coloring that camouflages it in the forest environment
E) a snapping turtle that uses its tongue to mimic a worm, thus attracting fish



Answer: C

Which of the following is an example of aposematic coloration?

Which of the following is an example of aposematic coloration?

A) stripes of a skunk
B) eye color in humans
C) green color of a plant
D) colors of an insect-pollinated flower
E) a katydid whose wings look like a dead leaf



Answer: A

Which of the following best describes resource partitioning?

Which of the following best describes resource partitioning? 

A) competitive exclusion that results in the success of the superior species
B) slight variations in niche that allow similar species to coexist
C) two species that can coevolve to share identical niches
D) differential resource utilization that results in a decrease in community species diversity
E) a climax community that is reached when no new niches are available



Answer: B

Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation?

Two barnacles, Balanus and Chthamalus, can both survive on the lower rocks just above the low-tide line on the Scottish coast, but only Balanus actually does so, with Chthamalus adopting a higher zone. Which of the following best accounts for this niche separation? 

A) competitive exclusion
B) predation of Chthamalus by Balanus
C) cooperative displacement
D) primary succession
E) mutualism



Answer: A

The lionfish is a venomous fish found primarily in the Red Sea and the Indian Ocean. In the 1990's, lionfish were accidentally released into the Atlantic Ocean, where they found abundant resources and favorable environmental condition. Which of the following scenarios is most likely to result in the lionfish having a major impact on the community into which they were introduced?

The lionfish is a venomous fish found primarily in the Red Sea and the Indian Ocean. In the 1990's, lionfish were accidentally released into the Atlantic Ocean, where they found abundant resources and favorable environmental condition. Which of the following scenarios is most likely to result in the lionfish having a major impact on the community into which they were introduced? 

(A) With no natural predators, the lionfish population will become very large.
(B) Some native species of invertebrates will develop a resistance to lionfish venom.
(C) Random mating will allow the lionfish population to reach Hardy-Weinberg equilibrium.
(D)A virus that specifically infects lionfish will become more prevalent.


Answer: A

Which of the following is the most accepted hypothesis as to why invasive species take over communities into which they have been introduced?

Which of the following is the most accepted hypothesis as to why invasive species take over communities into which they have been introduced? 

A) Invasive species are more aggressive than native species in competing for the limited resources of the environment. 

B) Invasive species are not held in check by the predators and agents of disease that have always been in place for the native species. 

C) Humans carefully select which species will outcompete nuisance native species. 

D) Invasive species have a higher reproductive potential than native species. 

E) Invasive species come from geographically isolated regions, so when they are introduced to regions where there is more competition, they thrive.

Answer: B

During the course of the formation of a parasite/host relationship, a critical first step in this evolution would be

During the course of the formation of a parasite/host relationship, a critical first step in this evolution would be 

A) changing the behavior of the host or intermediate host.
B) developing asexual reproduction.
C) deriving nourishment without killing the host.
D) starting as an ectoparasite and then later becoming an endoparasite.
E) utilizing heterotropic nutrition during infection and autotrophic nutrition during dormancy.



Answer: C

Based on the experimental results, which of the following is the best evolutionary explanation for the occurrence of ARD in C. elegans?

Based on the experimental results, which of the following is the best evolutionary explanation for the occurrence of ARD in C. elegans?

a. The ability to enter ARD provides a strong selective advantage because reproduction can occur despite periods of food scarcity

b. acquiring the genes for ARD gives individuals a selective advantage because they produce more offspring than do individuals who cannot enter ARD

c. Individuals who can enter ARD are selected for in the population because they live longer than do individuals who cannot enter ARD

d. individuals who can enter ARD have high fitness because they can reproduce even when food is scarce



Answer: A

Which of the following conclusions is most consistent with the data shown in Figure 2?

Which of the following conclusions is most consistent with the data shown in Figure 2?

a. animals that spend 3-5 days in ARD are more likely to survive periods of food scarcity than are animals that spend 13-15 days in ARD

b. animals that spend 30 days in ARD live significantly longer after reintroduction of food than animals that spend only 3 days in ARD

c. The number of days an animal spends in ARD does not significantly affect its time of survival after reintroduction of food

d. The large standard errors of the means make conclusions from the data impossible



Answer: C

The average brood size per mated individual upon reintroduction of food following 30 days of ARD is closest to which of the following?

The average brood size per mated individual upon reintroduction of food following 30 days of ARD is closest to which of the following?

a. 10

b. 50

c. 250

d. 400



Answer: B

Which of the following best describes the reproductive ability of C. elegans following the ARD induced in the first experiment?

Which of the following best describes the reproductive ability of C. elegans following the ARD induced in the first experiment?

a. mating with a well-fed male consistently produced more offspring than did reproduction via self-fertilization

b. the numbers of progeny produced by self-ferilization and by mating with well-fed males were not statistically different

c. C. elegans stopped reproducing after 20 days without food

d. there was no relationship between days without food and average brood size


Answer: A

A scientist is evaluating a proposal for raising large numbers of fish in ocean pens for human consumption. As part of the evaluation, the scientist is designing a plan for investigating how fish in the ocean pens might affect nearby ecosystems. Which of the following is the most appropriate factor to use as the dependent variable in the experimental investigation?

A scientist is evaluating a proposal for raising large numbers of fish in ocean pens for human consumption. As part of the evaluation, the scientist is designing a plan for investigating how fish in the ocean pens might affect nearby ecosystems. Which of the following is the most appropriate factor to use as the dependent variable in the experimental investigation?

a. the amount of metabolic wastes in the water where the fish are being raised

b. the water temperature in the natural habitat of the fish being studied

c. the types of fish that are preferentially consumed by humans



Answer: A

If a dam is built downstream and prevents salmon migration to the test sites, which of the following most accurately predicts the impact on nitrogen influx?

If a dam is built downstream and prevents salmon migration to the test sites, which of the following most accurately predicts the impact on nitrogen influx?

a. nitrogen influx will increase because the bears will no longer store nitrogen from the salmon

b. nitrogen influx will decrease because there will be less bear-salmon interaction

c. nitrogen influx will remain stable because organisms other than bears and salmon will mobilize nitrogen in the environment

d. nitrogen influx will increase because bears will longer lose nitrogen to the salmon



Answer: B

Which of the following pieces of additional data would help further investigate the relationship between bears, salmon, and influx of nitrogen into the local environment?

Which of the following pieces of additional data would help further investigate the relationship between bears, salmon, and influx of nitrogen into the local environment?

a. the experimenters should remove the remains of salmon carcasses immediately after the salmon are eaten by the bears and determine the nitrogen content of the carcasses

b. the experimenters should increase the number of bears in the area and measure the amount of nitrogen available for uptake by plants

c. the experimenters should set up a net to catch salmon before they enter the area and then measure nitrogen influx

d. the experimenters should clear cut the trees from the area and determine how much nitrogen remains in the streams



Answer: A

Which of the following most likely describes how the interaction between bears and salmon influences nitrogen dynamics in the environment?

Which of the following most likely describes how the interaction between bears and salmon influences nitrogen dynamics in the environment?

a. when bears consume salmon, they leave parts of the carcasses on the ground, which decompose, releasing nitrogen into the environment

b. when salmon swim upstream to spawn, bears migrate to the rivers, and deposit nitrogen from the forest with their excrement

c. bears are a reservoir for nitrogen because they are the top consumer in the environment

d. bears urinate in rivers and streams which provides nitrogen for the salmon



Answer: A

Which of the following statements is best supported by the data?

Which of the following statements is best supported by the data?

a. black bears are a keystone species

b. salmon are a keystone species

c. black bear urine is a significant source of nitrogen in the environment

d. the presence of black bears and salmon correlates with a significant increase in nitrogen influx



Answer: D

In the year 2000, specimens of C.taxifolia, a green algae used in tropical aquariums was found off the coast of California. It is native to the Indian Ocean. It is known for aggressive reproduction and an ability to compete with sea grasses. It is currently on an international list of invasive species. Which of the following best predicts the consequences of the introduction of C. taxifolia to the California coast?

In the year 2000, specimens of C.taxifolia, a green algae used in tropical aquariums was found off the coast of California. It is native to the Indian Ocean. It is known for aggressive reproduction and an ability to compete with sea grasses. It is currently on an international list of invasive species. Which of the following best predicts the consequences of the introduction of C. taxifolia to the California coast?

a. without natural herbivores or competitors, C. taxifolia will grow rapidly and crowd out native species of producers

b. C. taxifolia will have a hard time establishing itself because it will have to compete against native species of sea grasses, which are better adapted to the environment.

c. C. taxifolia will grow rapidly, leading to an increase in the diversity of producers



Answer: A