a.           Mucor secrets enzymes to digest organic compounds and absorbs the digested nutrients.

It cannot make its own nutrients from simple inorganic substances.

b.          Tapeworm lives inside the body of another animal to obtain nutrients but a dog lives independently.

Tapeworm absorbs nutrients from its host without the need of digestion but a dog needs to digest food substances in its gut/intestine before it can get the nutrients it needs.

c.           Similarity: they both depend on other organisms for the supply of nutrients.

Difference: tapeworm does not need to digest food but Mucor has to secret enzymes to digest organic compounds before of can absorb the nutrients.

d.          All structures except structure A are adaptive features for their nutrients. Both B and E provide large surface areas for the absorption of nutrients. B of Mucor allows it to grow into the organic matter to obtain nutrients. C and D of tapeworm are for attachment to the intestinal wall of the host. They ensure that the tapeworm stays inside the host.