NCERT 7th Class (CBSE) Science: Nutrition in Animals

Question: What happens to food in the Stomach and small intestine.

Answer: Stomach – The stomach is a thick walled, muscular bag like organ. The food that enters the stomach is digested with the help of digestive juices secreted by the walls of stomach. The digestive juices contains pepsin and hydrochloric acid. Pepsin digests the proteins present in food into simpler substances. Hydrochloric acid provides an acidic medium for the pepsin to act. In addition, it also kills the bacteria that could have entered with the food.

Small Intestine: The small intestine is the longest part of the alimentary canal. It is coiled and packed into the space below the stomach. It is nearly 7 m long.

Question: What is digestion?

Answer: The process by which food is broken down into simpler forms, which is absorbed by the body is called digestion.

Question: Define ingestion?

Answer: The process by which organisms take in the food is called ingestion.

Question: Where does the digestion start?

Answer: The digestion starts from the mouth and is completed in the small intestine.

Question: What is rumination?

Answer: Plant-eating animals quickly swallow their food after chewing it once. The swallowed food goes to a chamber called rumen. They bring back the food later into the mouth and chew it again. This process is called rumination.

Question: What are ruminants?

Answer: Animals that can bring the swallowed food back into their mouth where it is chewed again are called ruminants.

Question: Where is the caecum located in the body of the ruminant?

Answer: Ruminants have a large sac – like structure called caecum between small intestine and large intestine.

Question: What is absorption?

Answer: The process by which nutrients from the digested food are absorbed by the body is called absorption.

Question: What is assimilation?

Answer: The process by which the absorbed nutrients are utilized by the body for providing energy is called assimilation.

Question: What is egestion?

Answer: The process by which the undigested food is thrown out of  the body is called agestion.