Herbivorous animals can digest celulose because

Options

A. their molar and premolar teeth can crush and grind the food
B. Bacteria present in their caecum help in digestion of cellulose
C. Gastric juice has a digstive enzyme fòr cellulose digestion
D. Alimentary canal is very long

Answer

### Step-by-Step Solution:

1. **Understanding Herbivores**: Herbivorous animals primarily consume plant material, which is rich in cellulose. Cellulose is a complex carbohydrate that is difficult to digest.

2. **Role of Teeth**: Herbivores possess specialized molar and premolar teeth that are adapted to crush and grind plant materials. This mechanical breakdown is the first step in the digestion process.

3. **Microbial Fermentation**: The key to cellulose digestion in herbivores lies in the presence of symbiotic bacteria in their digestive system. These bacteria help break down cellulose through a process called microbial fermentation.

4. **Location of Bacteria**: In many herbivores, such as ruminants (e.g., cows, sheep), these bacteria are primarily located in the rumen, which is one of the four chambers of their stomach. In non-ruminants, such as rabbits, similar bacteria are found in the cecum.

5. **Digestive Process**: The fermentation process carried out by these bacteria produces enzymes that can break down cellulose into simpler sugars, which the herbivores can then absorb and utilize for energy.

6. **Conclusion**: Given the importance of the symbiotic bacteria in the digestion of cellulose, the correct answer to the question is option B: "Bacteria present in the cecum helps in digestion of cellulose."