Question

Cattle depend on microorganisms in their digestive tract to digest the cellulose in their diets. The cattle and the microorganisms are?

A. carnivores.
B. mutualistic symbionts.
C. herbivores.
D. parasitic symbionts.

Answer 1

I think it is b

Answer 2

They are mutualistic. The cattle cannot digest the cellulose from the plants they eat, and the bacteria (E. Coli) do it form them. The bacteria in turn, receive nutrients from digesting the cellulose, and they both end up benefiting.

Answer 3

In general, more complex animals are

A. More likely to rely on chemical digestion than to rely on mechanical digestion
B. more likely to perform intracellular digestion than extracellular digestion
C. more likely to have one body opening than to have two body openings
D. more likely to have a digestion tract than to have a gastrovascular cavity