Question

section: how species interact with each other
matching
write the letter of the term or phrase that best matches the description.

1. species a benefits and species b is killed. a. competition
2. species a and b negatively affect each other. b. predation
3. species a and b both benefit. c. parasitism
4. species a benefits and species b is unaffected. d. mutualism
5. species a benefits and species b is harmed e. commensalism

but not killed.
multiple choice
in the space provided, write the letter of the term or phrase that best completes
each statement or best answers each question.

1. which of the following statements is correct?

a. an organisms niche is only the part of its habitat that it eats.
b. an organisms habitat is a location.
c. habitat and niche are the same thing.
d. an organisms niche is outside its habitat.

1. which of the following is part of an american bisons niche?

a. grasslands c. water
b. gray wolf d. all of the above

1. when two species in an area eat the same type of food but eat at dif-

ferent times of the day, their niches
a. are the same.
b. are examples of commensalism.
c. overlap.
d. eliminate competition.

1. if exponential growth occurs in the population of a species of preda-

tor, the population of its prey will most likely
a. decrease quickly. c. stay the same.
b. increase slowly. d. experience exponential growth.

1. if two species coevolve, they may develop adaptations that

a. reduce the harm of the relationship.
b. increase the benefit of the relationship.
c. prevent any relationships.
d. both (a) and (b)

Explanation:

• Question 6:
• An organism's niche is its role in the ecosystem (how it eats, interacts, etc.), not just the part of the habitat it eats (so a is wrong).
• Habitat is a location (where an organism lives), so b is correct.
• Habitat (location) and niche (role) are different (so c is wrong).
• Niche is within the habitat (so d is wrong).
• Question 7:
• American bison's niche includes grasslands (where it feeds), gray wolf (a predator it interacts with), and water (a resource it needs). So all of the above (d) is correct.
• Question 8:
• If two species eat the same food but at different times, their niches overlap (as there is some similarity in resource use). It's not the same niche (a is wrong), not commensalism (b is wrong as commensalism is one - species - benefits - and - the - other - is - unaffected), and it doesn't eliminate competition completely (d is wrong as there is still some overlap in food resource).
• Question 9:
• If a predator's population has exponential growth, it will consume more prey, so the prey population will most likely decrease quickly (a). It won't increase (b) or stay the same (c), and prey won't have exponential growth (d) as they are being eaten.
• Question 10:
• Coevolution can lead to adaptations that reduce harm (e.g., in a predator - prey coevolution, prey may develop better escape mechanisms reducing harm from predators) and/or increase benefit (e.g., in a mutualistic coevolution like between flowers and pollinators, both may develop better adaptations for the relationship). So both (a) and (b) (d) is correct. It doesn't prevent relationships (c is wrong).

Answer:

1. b. An organism's habitat is a location.
2. d. all of the above
3. c. overlap.
4. a. decrease quickly.
5. d. Both (a) and (b)