Question

For the digestion of cellulose, an enzyme called cellulase is required. Some mammals lodge cellulase producing bacteria in their digestive system by offering them food and shelter. These mammals are mostly ____________.
A. Herbivores
B. Carnivores
C. Omnivores
D. Sanguivores

Answer 1

Hint: Digestion of cellulose takes place in ruminants. The first compartment is the rumen, where food containing cellulose ingested is stored temporarily and later on regurgitated to chew their cud. Ruminants are able to digest cellulose because of the presence of bacteria and enzymes in their rumen where the process of anaerobic bacterial digestion occurs. Methane is a by-product of this type of digestion.

Complete answer:
Option A. Herbivores: Animals that get its energy from eating plants, and only plants are known as herbivores. Most herbivores have a special type of digestive system which allows them to digest all kinds of plants, including grasses. Herbivores digest cellulose by the process of microbial fermentation. They have cellulase producing bacteria in their digestive system which helps them for the digestion of cellulose.
Hence option A is the correct answer.
Option B. Carnivores: An organism that mostly eats meat, or the flesh of animals are known as carnivores. Carnivores sometimes are called predators. There are many carnivores that eat herbivores. Some eat omnivores, while others devour other carnivores. They do not have cellulose digesting bacteria in their digestive system.
Hence option B is not correct.
Option C. Omnivores: Animals that have the ability to eat and survive on both plant and animal matter are known as omnivores. These animals obtain energy and nutrients from plant and animal matter by digesting carbohydrates, protein, fat, and fiber, and metabolizing the nutrients and energy of the absorbed sources. They do not have cellulose digesting bacteria in their digestive system.
Hence option C is not correct.
Option D. Sanguivores: The animals which suck blood and feed on them are called sanguivores. Leech, vampire bat and female mosquito are examples of sanguivores. They do not have the ability to digest cellulose.
Hence option D is incorrect.

So, Option A. Herbivores is the correct answer.

Note:
Herbivores are primary consumers which means that they feed on autotrophs. Herbivory is limited usually to those animals that eat plants. Plant pathogens are those which feed on living plants such as fungi, bacteria and protists, while fungi and microbes which feed on dead plants are called saprotrophs. Parasitic plants are those flowering plants that obtain nutrition from other living plants.