Long Answered Questions: 

Ques:- What is assimilation?
Ans:- The absorbed substances are transported via the blood vessels to different organs of the body where they are used to build complex substances such as the proteins required by the body. This process is called assimilation.

Ques:- What is tooth decay?
Ans:- If we don’t clean our mouth properly after eating it results in growth of harmful bacteria, which break down the sugars present from leftover food and release acids. These acids damage the teeth. This is called tooth decay.

Ques:- Write the functions of saliva.
Ans:- The functions of saliva;
(i) It makes the chewed food soft for swallowing.
(ii) It breaks down the starch into sugars.

Ques:- Write the functions of tongue.
Ans:- The functions of tongue;
(i) We use our tongue for taking.
(ii) It mixes saliva with the food.
(iii) It helps in swallowing food.
(iv) We taste food with our tongue.

Ques:- Name the processes which define the nutrition in human beings.

    Or

Ques:- Name the complex processes by which nutrition is completed.
Ans:- There are five complex processes which define the nutrition in human beings.
(i) ingestion
(ii) digestion
(iii) absorption
(iv) assimilation
(v) egestion

Ques:- What are villi? Write its function.
Ans:- Many small finger-like outgrowths are situated in the inner walls of small intestine, these are called villi.
The villi increase the surface area for absorption of the digestive food.

Ques:- Why can we not digest the cellulose like the cattle?
Ans:- The cattle have a large sac-like structure called caecum between the small intestine and large intestine. The cellulose of the food is digested here by the action of the certain bacteria which are not present in humans.

Ques:- Name the structure in amoeba which helps it to capture the food.
Ans:- Pseudopodia

Ques:- How does amoeba take food?
Ans:- When amoeba senses food it pushes out pseudopodia around the food particle and engulfs it. The food becomes trapped in a food vacuole. Digestive juices are secreted into the food vacuole. They act on the food and break it down into simpler substances. Gradually the digested food is absorbed.

Ques:- Draw a label diagram of amoeba.
Ans:-