Refer to the figure showing the digestive systems of three organisms. Based on the figure, which of these animals has a gut that is best adapted for grinding up the food they ingest prior to chemical digestion, and what is the structure that allows this?

Question

Refer to the figure showing the digestive systems of three organisms.  Based on the figure, which of these animals has a gut that is best adapted for grinding up the food they ingest prior to chemical digestion, and what is the structure that allows this?

Quizplus · Accepted Answer

Animals 1 and 2 have gizzards, which are muscular structures that grind up food to aid in mechanical digestion before it enters the stomach for chemical digestion. This adaptation is particularly useful for animals that consume tough plant material, such as the insects and seeds that make up the diets of birds and reptiles like those shown in the figure. The presence of a cecum (choice C) would be more indicative of an animal adapted to digesting cellulose or other complex carbohydrates, such as herbivorous mammals. The other choices (A and B) do not provide evidence of adaptations for grinding or mechanical digestion.

Refer to the Figure Showing the Digestive Systems of Three