Which part of the avian digestive system acts as a replacement for teeth by mechanically grinding their food for them?

a. Crop

b. Gall bladder

c. Gizzard

d. Proventriculus

Answer: c. Gizzard

Explanation:

The Gizzard or ventriculus is the part of the digestive system of the aves, which acts as a mechanical stomach. It is composed of two sets of muscles that act as a avian teeth. It also posses the thick lining that protects those muscles. The gizzard facilitates the mechanical break down of the food as may be caused by the teeth.