Question

c. commensalism
d. predation

1. in a mutualistic relationship:

a. one species benefits, the other is harmed
b. both species benefit
c. one species benefits, the other is unaffected
d. both species are harmed

1. the relationship between a barnacle (that attaches to a whale) and the whale is an example of:

a. mutualism
b. parasitism
c. commensalism
d. competition

1. a hawk feeding on a mouse represents:

a. competition
b. parasitism
c. herbivory
d. predation

1. which term describes the role an organism plays in its environment, including its habitat and interactions?

a. community
b. niche
c. trophic level
d. biome

1. a keystone species is important because:

a. it has the largest population in the community
b. it provides food for every species
c. it has a disproportionately large effect on community structure
d. it is the top predator in every ecosystem
part ii: short answer

1. explain how genetic variation is important for natural selection.
2. describe the difference between sympatric and allopatric speciation.
3. give one real - world example of coevolution, and explain how the two species affect each other’s evolution.

Explanation:

• Question 6: Mutualism is a symbiotic relationship where both species benefit. For example, bees and flowers: bees get nectar (food), and flowers get pollinated (reproduction aid).
• Question 7: Commensalism is when one species benefits and the other is unaffected. Barnacles attach to whales. Barnacles get a place to live and access to food (plankton in moving water), while whales are generally not harmed or helped significantly.
• Question 8: Predation is when one organism (predator) kills and eats another (prey). A hawk (predator) feeding on a mouse (prey) is a classic example.
• Question 9: A niche describes an organism's role in its environment, including its habitat and interactions. For instance, a beaver's niche involves building dams (modifying habitat) and being a herbivore (interaction with plants).
• Question 10: A keystone species has a disproportionately large effect on community structure relative to its abundance. For example, sea otters (by controlling sea urchin populations, which would over - graze kelp forests if not controlled).

Answer:

1. B. Both species benefit
2. C. Commensalism
3. D. Predation
4. B. Niche
5. C. It has a disproportionately large effect on community structure