Tag: biology

The ruminants bring back swallowed grass into their mouth and chew it for sometime. Grass has cellulose. It is the carbohydrate which can only be digested by ruminants because they have rumen. When they eat grass, it is sent to the rumen where enzymes acts on it and softens it. Softened cellulose is called cud. It is sent back to the mouth where ruminants chew it for sometime.

Methanogens are a group of archaebacteria that occur in marshy areas where they convert formic acid and carbon dioxide into methane. Some of the methanogen archaebacteria live as symbionts (Eg. Methanobacterium) inside the rumen or first chamber in the stomach of herbivorous animals that chew their cud (ruminants). These archaebacteria are helpful to the ruminants in the fermentation of cellulose. 

Cud is a portion of food that returns from a ruminant's stomach to the mouth to be chewed for the second time. Cows spend nearly eight hours out of every day chewing their cud. Hence, option A is correct.

The ruminant stomach is composed of 4 separate compartments. Food passes first into the 'rumen', then 'reticulum', 'omasum' and finally into the 'abomasum'. The first three compartments helps in digestion of complex carbohydrates with the aid of microorganisms, which produce volatile fatty acids. The abomasum functions similarly to the carnivore stomach as it is glandular and digests food chemically, rather than mechanically or by fermentation like the other 3 chambers of the ruminant stomach. Hence, option A is correct.

• The animals which partially digest food have a four-chambered stomach and the process of digestion is as follows: The food is chewed and swallowed quickly and passed into the first stomach called Rumen.
•  Then the microorganisms help in breaking down the food and this partially digested food is called cud. Hence, the rumen is the stomach part in which herbivores secretes the grass which is swallowed quickly.

• The animals which partially digest food have four chambered stomach and the process of digestion is as follows: The food is chewed and swallowed quickly and passed into the first stomach called Rumen.
•  So, the animals are referred to as ruminants. Then the microorganisms help in breaking down the food and this partially digested food is called cud. Hence, Partially digested food in ruminants is cud.

Ruminant animals such as cattle, buffalo, sheep, goat and camel have a compound stomach, which consists of four chamber, viz, rumen, reticulum, omasum and abomasum. Rumen is the first and the largest of the four chambers. Rumen and reticulum harbour numerous bacteria and protozoa, which carry out extensive fermentation of cellulose. So, these two chambers function as sites for cellulose digestion in ruminants. The gastric juice containing enzymes and HCl is secreted only by the fourth chamber i.e., Abomasum.