Question

The esophagus, crop, gizzard, and intestine are found in: a. birds and mammals. b. insects and mammals. c. flatworms and birds. d. earthworms and birds. e. sponges and cnidarians.

Short answer

The correct answer is D. Both birds and earthworms have the esophagus, crop, gizzard, and intestine in their digestive systems.

Step-by-step solution

Examining Answer A

Birds contain the mentioned parts while mammals do not have a crop or gizzard. This part helps birds grind their food, a process that mammals perform using their teeth. So, the answer is not A.

Examining Answer B

Mammals don't have a crop or gizzard, while insects have a different digestion system that doesn't include these parts. So, the answer can't be B.

Examining Answer C

Birds have all these parts but flatworms don't. Flatworms have a primitive digestive system usually with one opening. So, the answer can't be C.

Examining Answer D

Both birds and earthworms have these parts in their digestive systems. Earthworms have a crop and gizzard that are used to store and grind food. So, this could be the correct answer.

Examining Answer E

Sponges and cnidarians have vastly different digestion systems and do not have these specific parts. So, the answer is definitely not E.