Question

How do birds digest their food in the absence of teeth?

a) By using acidic secretions in their crop
b) By mechanical breakdown using gizzard stones
c) By fermentation in their crop
d) By regurgitating food for further chewing

Answer 1

Birds have a unique digestive system that allows them to process food without teeth. They use a two-chambered stomach, with the proventriculus producing gastric juices and the gizzard mechanically grinding the food with swallowed stones. Most chemical digestion and absorption of nutrients occur in the intestine.

Step-by-step explanation:

Birds have a two-chambered stomach consisting of the proventriculus and the gizzard. The proventriculus secretes gastric juices to help digest the food before it enters the stomach, while the gizzard stores, soaks, and mechanically grinds the food using swallowed stones. The undigested material forms food pellets that are sometimes regurgitated. Most of the chemical digestion and absorption of nutrients happens in the intestine.