Cellulose is fermented in which of the following structures in rabbits?
a. Small intestine
b. Cecum
c. Abomasum
d. Rumen

Verified step by step guidance

1. Understand the digestive system of rabbits: Rabbits are hindgut fermenters, which means they have a specialized part of their digestive system where fermentation of plant material occurs.
2. Identify the role of the cecum: In hindgut fermenters like rabbits, the cecum is a large pouch located at the junction of the small and large intestines. It plays a crucial role in the fermentation of fibrous plant materials such as cellulose.
3. Compare the options: a. Small intestine - primarily involved in nutrient absorption, not fermentation. b. Cecum - the site of fermentation in rabbits. c. Abomasum - part of the stomach in ruminants, not present in rabbits. d. Rumen - part of the stomach in ruminants, not present in rabbits.
4. Eliminate incorrect options: Since rabbits are not ruminants, options c (abomasum) and d (rumen) can be eliminated. The small intestine (option a) is not the primary site for fermentation.
5. Conclude with the correct structure: Based on the understanding of rabbit digestion, the cecum (option b) is the structure where cellulose is fermented in rabbits.

Key Concepts

Cellulose Fermentation

Cellulose fermentation is a process where microorganisms break down cellulose into simpler compounds, typically in the digestive system of herbivores. This process is crucial for animals that consume plant material, as cellulose is a major component of plant cell walls and is not digestible by mammalian enzymes alone.

Cecum

The cecum is a pouch-like structure in the digestive tract of many animals, including rabbits, where fermentation of fibrous plant material occurs. It houses a large population of bacteria that aid in breaking down cellulose, allowing the animal to extract nutrients from plant-based diets effectively.

Herbivore Digestive Adaptations

Herbivores have evolved specialized digestive systems to process plant material efficiently. These adaptations include structures like the cecum, rumen, and others, which facilitate microbial fermentation of cellulose, enabling the extraction of energy and nutrients from fibrous plant tissues.