Class 6 Science Chapter 1 Practice Question Answers - Components of Food

Q1: Why does our body need nutritious food?
Ans:

• Food provides nutrients for the proper growth and functioning of the body.
• It gives protection against diseases.
• It provides energy to carry out physical activities.
• Nutrients are the fuel we need to enable the body to break down food and then put this to use in the body to repair and build cells and tissue.
• Nutrients are the components of food the body needs in adequate amounts for growth, reproduction, and leading a normal healthy life.
• The components of nutritious foods are carbohydrates, proteins, fats, vitamins, and minerals.

Q2: What are the roles of
(a) carbohydrates?
(b) fats?
(c) vitamins?
(d) minerals?
Ans: (a) Role of carbohydrates: Carbohydrates provide us with energy.
(b) Role of fats: Fats provide us with energy.
(c) Role of vitamins: Vitamins keep us healthy and protect us from many diseases. They are needed for the proper functioning of body parts. They help the body metabolise proteins and carbohydrates.
(d) Role of minerals: Minerals help to strengthen our bones and teeth. It maintains healthy skin, hair, and nails. It balances water levels. They also help to prepare blood.

Q3: Boojho was having difficulty watching things in dim light. The doctor tested his eyesight, and he prescribed a particular vitamin supplement. He advised him to include a few food items in his diet regularly.
(a)  Which deficiency disease is he suffering from?
(b) Which component of food is he lacking in his diet?
(c) Suggest some (any four) food items that he should include in his diet,
Ans: (a) He is suffering from night blindness. Night blindness is the inability to see objects in dim light.
(b) Vitamin A may be lacking in his diet. This is because the deficiency of vitamin A causes night blindness.
(c) Carrot, mango, papaya, green leafy vegetables, fish oil milk, etc., are food items rich in vitamin A. Therefore, Boojho should include these food items in his diet.

Q4: Paheli and Boojho peeled some potatoes and cut them into small pieces. They washed and boiled the potatoes in water. Then they threw away the excess water and fried the potatoes in oil, adding spices and salt. Although the potato dish tasted very good, it had fewer nutrients. Suggest a cooking method for potatoes that will not lower their nutrients.
Ans: Potatoes are very nutritious vegetables that provide carbohydrates, vitamins (especially vitamin C), minerals and dietary fibre. The skin of the potatoes provides extra nutrients and dietary fibre.
Methods of cooking potatoes which will not lower their nutrient values are:

• Wash the potatoes 
• Cut them into thin slices. 
• Cook the potatoes in a little amount of oil and some water.
• Add salt and spices to it. 
• While cooking, cover the cooking pot with a lid.

This method helps to preserve the nutrients of potatoes.

Q5: ‘Water does not provide nutrients, but it is an essential component of food’. Explain.
Ans: Water is a vital component of our food because
(i) It helps our body to absorb nutrients from food.
(ii) It maintains the temperature of our body.
(iii) Water transports nutrients throughout the body.
(iv) Water helps in removing wastes in the form of urine and sweat.

Q6: Given below are the steps to identify the presence of proteins in a food.
(i)  Next take a small quantity of the food sample in a test tube, add ten drops of water and shake it.
(ii)  First make a paste of food or powder of food to be tested.
(iii)  Finally add ten drops of caustic soda solution to the test tube and shake well.
(iv) Then add two drops of copper sulphate solution.
Which of the following is the sequence of the correct steps?
(a) i, iv, ii, iii
(b) ii, i, iv, iii
(c) ii, iii, iv, i
(d) iv, ii, i, iii
Ans: (b)
To identify the presence of proteins in a portion of food, first, make a paste of food or powder of food to be tested (ii).
Next, take a small quantity of the food in a test tube, add 10 drops of water and shake it (i).
Then add 2 drops of copper sulphate solution to it (iv).
Finally, add 10 drops of caustic soda solution to the test tube and shake well (iii).
Keep the test tube stand for a few minutes and observe the colour of the solution in the test tube. The appearance of violet colour indicates the presence of proteins in the food item.

Q7: What are the major functions of protein in our body?
Ans: The main functions of protein in our body are:

• It supplies materials needed to make new cells by the body and repair the damaged cells.
• Protein is important for growth and development in children, teens, and pregnant women.
• They are important to the body’s structure, function, and regulation.

Q8: What is a balanced diet?
Ans:

• A diet which contains all the essential components in the right proportion is called a balanced diet.
• The essential components include carbohydrates, vitamins, minerals, proteins, fats, fibres, and water.

Q9: ‘Vitamins and minerals are essential in very small quantities by our body compared to other components, but still, they are an important part of our balanced diet. Explain the statement.
Ans: Vitamins and minerals are needed in very small quantities but are essential for the normal functioning of our body. It is because
(i) They are protective foods and help protect our bodies against diseases.
(ii) They help in maintaining good health.
(iii) They help in the normal growth of our body.

Q10: Name the food materials which contain fat.
Ans: The food materials which contain fat are: 

• Ghee
• Butter
• Cheese
• Egg 
• Meat
• Milk

Q11: While using iodine in the lab, a few iodine drops fell on Paheli’s socks, and a few fell on her teacher’s saree. The iodine drops on the saree turned blue-black, while their colour did not change on the socks. What can be the possible reason?
Ans: The Paheli’s teachers’ saree might have been starched. We know that starch turns blue-black with iodine solution. So the saree also turned blue-black. But Paheli’s socks did not have starch and thus did not show any change of colour.

Q12: List some common sources of carbohydrates.
Ans: Some common sources of carbohydrates are: 

• Sweet potatoes
• Wheat
• Sugar
• Honey
• Rice
• Maize
• Millet

Q13: Name the major nutrients in our food.
Ans: Major Nutrients in our food are

• Carbohydrates
• Proteins
• Lipids
• Vitamins
• Minerals and 
• Dietary fibres.

Q14: List the various types of vitamins.
Ans: The various types of vitamins are:

• Vitamin A
• Vitamin B
• Vitamin C
• Vitamin D
• Vitamin E and
• Vitamin K.

Q15: Name the vitamin present in orange and lemon.
Ans: The vitamin present in oranges and lemons is Vitamin C.

Q16: How will you test for starch in a food sample?
Ans:

• Take a small quantity of food samples.
• Then add 2-3 drops of iodine solution to it. 
• The appearance of a blue-black colour indicates that the food sample contains starch.

Q17: Name the different food groups.
Ans: Food can be broadly subdivided into the following three groups

• Energy-giving foods
• Bodybuilding foods
• Protective foods

Q18: Name the deficiency disease caused by iron deficiency.
Ans: The deficiency of disease caused by iron deficiency is anaemia.

Q19: (a) List all those components of food which provide nutrients.
(b) Mention two components of food which do not provide nutrients.
Ans: (a) Components of food which provide nutrients are carbohydrates, proteins, fats, vitamins and minerals.
(b) Components of food which do not provide nutrients are roughage and water.

Q20: Which minerals are required to build our bones and teeth?
Ans: Minerals are needed to build our bones, and teeth are

• Calcium 
• Phosphorus.