A. Fill in the blanks
- Living organisms need food to grow and work.
- Vitamins A, D, E and K are soluble in fat, whereas Vitamin B and C are water soluble.
- The deficiency of Vitamin B1, in the diet, causes a disease called Beri-Beri.
- Vitamin K helps in clotting of blood.
- The dietary fibres constitute roughage.
B. Write True or False for the following statements
- Vitamins and minerals are body building foods. — False
- Our skin makes Vitamin E in the presence of sunlight. — False
- Deficiency of phosphorous can lead to anaemia. — False
- We should eat food that has all its essential components in the right proportions. — True
- Kwashiorkor occurs due to the deficiency of fat in the diet. — False
C. Tick (✓) the correct option
- When iodine solution turns blue-black on potato, it indicates the presence of — starch
- The deficiency of Vitamin A causes — night blindness
- 4. A child, who has bow legs, is suffering from a deficiency disease known as —
✔ rickets
5. The deficiency of proteins in the diet of children can cause a disease known as —
✔ kwashiorkor
D. Answer the following questions in brief
1. Name the important sources of our food.
The main sources of our food are plants and animals.
Plants give us food items such as fruits, vegetables, cereals, pulses, sugar, and oils.
Animals provide us milk, eggs, meat, fish, and honey.
Thus, both plants and animals are important sources of our food.
2. State the importance of carbohydrates in our diet.
Carbohydrates are called energy-giving foods because they provide energy to our body.
This energy helps us to do all kinds of work such as walking, running, playing, studying, and other daily activities.
Foods like rice, wheat, potatoes, and sugar are rich in carbohydrates.
3. Name the vitamin whose deficiency causes the disease of—
(a) Night blindness is caused due to the deficiency of Vitamin A.
This vitamin is necessary for good eyesight.
(b) Beri-beri is caused due to the deficiency of Vitamin B₁.
It affects the nerves and muscles.
(c) Scurvy is caused due to the deficiency of Vitamin C.
It causes bleeding gums and weakness.
(d) Rickets is caused due to the deficiency of Vitamin D.
It makes bones weak and soft.
4. Name any three of the minerals needed by our body.
Three important minerals needed by our body are:
Calcium – for strong bones and teeth
Iron – for making blood
Iodine – for proper functioning of the thyroid gland
These minerals are essential for proper growth and good health.
5. State the role of calcium in our body.
Calcium helps in the formation of strong bones and teeth.
It also helps in the proper working of muscles and nerves.
A lack of calcium can make bones weak.
6. Write the full forms of the terms PEM and PCM.
PEM stands for Protein Energy Malnutrition.
It is caused due to lack of proteins and energy-giving food in the diet.
PCM stands for Protein Calorie Malnutrition.
It occurs when the body does not get enough proteins and calories.
Answer the following questions
1. Write the importance of the following in our diet:
(a) Carbohydrates
Carbohydrates are the main source of energy for our body.
They help us to do daily activities such as walking, running, studying, and playing.
(b) Proteins
Proteins are body-building foods.
They help in the growth and repair of body tissues and make our muscles strong.
(c) Fats
Fats give us energy and help keep the body warm.
They also store energy for future use.
(d) Roughage
Roughage helps in the easy movement of food through the digestive system.
It prevents constipation and keeps the digestive system healthy.
(e) Vitamin A
Vitamin A helps in maintaining good eyesight.
It keeps our skin healthy and protects us from night blindness.
(f) Vitamin C
Vitamin C helps to keep our gums and teeth healthy.
It also protects us from scurvy and improves body resistance.
2. Describe one test each for detecting the presence of the following in food:
(a) Proteins
Take a little food sample and add a few drops of copper sulphate solution and caustic soda solution.
If the food turns violet, it shows the presence of proteins.
(b) Starch
Add a few drops of iodine solution to the food sample.
If the food turns blue-black, starch is present.
(c) Fats
Rub the food item on a piece of paper.
If the paper shows a greasy translucent spot, fats are present.
3. Why do we need proteins and how do they affect our health?
Proteins are needed for the growth and repair of the body.
They help in building muscles, skin, blood, and other tissues.
Proteins keep the body strong and healthy.
Lack of proteins in the diet can cause diseases like kwashiorkor and marasmus, especially in children.
This may lead to weakness, poor growth, swelling of the body, and thin muscles.
4. A mineral ‘X’ is essential for the formation of a component ‘Y’, in the blood of a person. The function of component Y is to transport oxygen in the body. The deficiency of mineral ‘X’, in the diet of a person, causes a disease Z. Identify X, Y and Z. Also mention the symptoms of disease Z.
The mineral X is iron.
The component Y is haemoglobin.
The disease Z is anaemia.
Iron is needed for the formation of haemoglobin in the blood.
Haemoglobin carries oxygen to all parts of the body.
If a person does not get enough iron, he may suffer from anaemia.
The symptoms of anaemia are:
- Weakness
- Tiredness
- Pale skin
- Lack of energy
5. Deficiency of iodine is more common in mountainous regions. Why?
In mountainous regions, the soil and water contain less iodine because iodine gets washed away by rain.
As a result, the food grown there also contains less iodine.
People living in these areas may suffer from iodine deficiency, which can cause goitre, a disease in which the neck swells due to enlargement of the thyroid gland.
6. What is a balanced diet? Why should we take a balanced diet?
A balanced diet is a diet that contains all the nutrients such as carbohydrates, proteins, fats, vitamins, minerals, roughage, and water in the right amounts.
We should take a balanced diet because:
- It provides energy to the body.
- It helps in growth and repair of tissues.
- It keeps us healthy and strong.
- It protects us from deficiency diseases.
- It helps the body function properly.
Thus, a balanced diet is essential for good health.
Also read: DAV Class 8 SST Chapter 6 – Natural Resources, Minerals & Energy | DAVSolutions