Lesson: Nutrition in Animals

# Question: 1

Which animals chew the food bolus?

Ruminants

# Question: 2

Where in the alimentary canal does the food get completely digested?

Small intestine

# Question: 3

Which part of the digestive organ does the rumen belong to?

Stomach

# Question: 4

## Solution:

(a) Contractile vacuole

(b) Food vacuole

# Question: 5

## Solution:

A patient of diarrhoea should be given at regular intervals the oral rehydration solution (ORS).

Incisors

Canines

# Question: 1

What is the mode of nutrition in starfish?

Solution:

Starfish eats animals that have a hard shell on their bodies.  Once the shell is opened and the soft animals inside it exposed, the starfish brings out its stomach through its mouth and eats it. After eating, the stomach goes back inside the body, and digestion takes place slowly.

# Question: 2

What is the function of teeth in digestion?

Solution:

# Question: 3

Name all the parts that make up the human alimentary canal.

Solution:

The digestive tract can be categorized into various parts:

(1) Mouth or the buccal cavity,

(2) Food canal or Oesophagus,

(3) Stomach

(4) The small intestine,

(5) The large intestine with rectum, and

(6) The anus.

# Question: 4

What is the function of salivary glands in our mouth?

Solution:

# Question: 5

Why do we understand the taste even if we do not see the food that we are eating?

Solution:

# Question: 6

Why does tooth decay occur?

Solution:

# Question: 7

What is absorption and assimilation in the process of digestion?

Solution:

# Question: 1

Explain digestion.

Solution:

The human digestive system is made up of the alimentary canal and digestive glands. The different parts of the digestive system are the (i) buccal cavity, (ii) oesophagus, (iii) stomach, (iv) small intestine, (v) large intestine ending in rectum and (vi) anus. The main digestive glands secreting digestive juices are (i)the salivary glands, (ii)the liver and (iii)the pancreas (iv)The stomach and small intestinal walls.

Digestion is a complex process that involves ingestion, digestion, absorption, assimilation and egestion. Digestion of carbohydrates (starch) begins in the mouth or buccal cavity, while the digestion of protein starts in the stomach. The bile juice from the liver, the pancreatic juice secreted by the pancreas, and the digestive juice from the intestinal wall help in the completion of digestion of all food components in the small intestine, from where the digested food is absorbed by the villi and transported by the blood vessels to various parts of the body. The large intestine absorbs water and some salts, and finally the undigested and unabsorbed waste faecal matter is expelled out of the body through the anus.

# Question: 2

Give a labelled diagram of the digestive system in humans.

Solution:

Question: 3

Discuss the four types of teeth in humans.

Solution:

Teeth help to cut, grind and chew food, making digestion easier. Each type of tooth with its different shape has a different job to perform. Types of teeth include:

(a)  Incisors:  The eight teeth in the front (four on upper part and four down) are the incisors. These help you to take bite your food.

(b)  Canines: The next four teeth (two on each jaw) are the canines. They are sharp and used for tearing food.

(c)   Premolars: The next four teeth (two on each jaw) are the premolars and are used for chewing and grinding food.

(d)  Molars: The next three pairs of teeth (three pairs in each jaw) are the molars and are used for chewing and grinding food.

Question: 4

Draw and label the different taste buds in human tongue.

Solution:

Question: 5

How does amoeba get its nutrition?

Solution:

Amoeba eats microscopic organisms, which it captures by engulfing the food particle with its pseudopodia. The food is trapped in a food vacuole and digestive juices are then secreted in the food vacuole. These juices break down the food into simpler substances, which is then are absorbed. The absorbed substance is then utilized for growth, maintenance of the body activities, and reproduction; while the undigested food is expelled from the body by the vacuole.