Question

study the food web below.
tundra food web
all animals are decomposed after death

1. what would be the effect(s) of the muskrat population getting a disease?

a. the polar bear would have less to eat.
b. the grizzly bear, the arctic fox and the snowy owl would have less to eat.
c. the grasses and lichens would increase.
d. both b and c are correct.

1. in this same food web, which species is the least likely to be affected by food shortages?

a. polar bear
b. arctic hare
c. grizzly bear
d. caribou

Explanation:

33.

• Option a: Polar bear doesn't eat muskrat, so this is wrong.
• Option b: Grizzly bear, Arctic fox and snowy owl eat muskrat. If muskrat population decreases due to disease, they have less food.
• Option c: Muskrats eat grasses and lichens. If muskrat population decreases, grasses and lichens would have less herbivory pressure and may increase.
• Option d: Since both b (predators of muskrat have less food) and c (prey of muskrat - grasses and lichens increase) are correct.

• Option a: Polar bear has limited food sources (mainly from a few top - level connections in the food web).
• Option b: Arctic hare mainly depends on moss.
• Option c: Grizzly bear has multiple food sources (muskrat, arctic hare etc.), so it is less likely to be affected by food shortages as it can switch to other available foods.
• Option d: Caribou has relatively fewer food options compared to grizzly bear.

Answer:

d. Both b and c are correct.

34.