RBSE Class 7 Science Notes Chapter 2 Nutrition in Animals

These comprehensive RBSE Class 7 Science Notes Chapter 2 Nutrition in Animals will give a brief overview of all the concepts.

RBSE Class 7 Science Chapter 2 Notes Nutrition in Animals

→ Animal nutrition includes nutrient requirement, mode of intake of food and its utilization in the body.

→ The steps of taking nutrition in animals are - Ingestion, Digestion, Absorption, Assimilation (utilizing the absorbed nutrient to get energy) and Egestion (excreting the waste material).

→ The mode of taking food into the body varies in different organisms.

→ The alimentary canal can be divided into various compartments :

• The buccal cavity,
• food pipe or oesophagus,
• stomach,
• small intestine,
• large intestine ending in rectum, and
• the anus.

→ The digestive tract and the associated glands together constitute the digestive system.

→ Our teeth vary in appearance and perform different functions. For teasing, cutting and chewing food, there are four types of teeth : incisors, canines, premolars and molars.

→ Our mouth has the salivary glands which secrete saliva. The saliva breaks down the starch into sugars.

→ The inner lining of the stomach secretes mucus, hydrochloric add and digestive juices.

→ The small intestine is highly coiled and is about 7.5 metre long. It receives secretions from the liver and the pancreas.

→ The villi increase the surface area for absorption of the digested food.

→ In the cells, glucose breaks down with the help of oxygen into carbon dioxide and water, and energy is released.

→ The large intestine is about 1.5 metre in length. Its function is to absorb water and some salts from the undigested food material.

→ The grazing animals like cows, buffaloes and deer are known as ruminants. They quickly ingest, swallow their leafy food and store it in the rumen. Later, the food returns to the mouth and the animal chews it peacefully.

→ When amoeba senses food, it pushes out pseudopodia around the food particle and engulfs it. The food becomes trapped in a food vacuole.