You Must Know
1. Living organisms need food to grow and survive.
2. The sources of our food are plants and animals.
3. Carbohydrates, proteins, fats, minerals, vitamins, water and roughage are the
important components of our food.
4. Carbohydrates and fats mainly provide energy to our body.
5. Proteins and minerals are needed for the growth and maintenance of our body.
6. Vitamins help in protecting our body against diseases.
7. Deficiency of vitamins and minerals, in our diet, may result in deficiency diseases.
8. A diet which contains all the essential components of food, in right proportions, is called a balanced diet.
9. The lack of some of the essential nutrients in the diet is known as malnutrition.
10. Eating, more than the requirement of one’s body, can make the person obese.
Something To Know
A. Fill in the blanks.
1. Living organisms need food to grow and survive.
2. Vitamins A, D, E and K are soluble in fat and whereas Vitamin B and C are water soluble.
3. The deficiency of Vitamins B in the diet, causes a disease called Beri-Beri.
4. Vitamin K helps in clotting of blood.
5. The dietary fibres constitute roughage.
B. Write True or False for the following statements.
1. Vitamins and minerals are body building foods. False
2. Our skin makes Vitamin E in the presence of sunlight. False
3. Deficiency of phosphorous can lead to anaemia. False
4. We should eat food that has all its essential components in the right proportions. True
5. Kwashiorkor occurs due to the deficiency of fat in the diet. False
C. Tick (✔) the correct option.
1. When a drop of iodine solution was put on the cut surface of a potato, it turned blue-black in colour. This indicates the presence of-
vitamin
protein
fat
starch (✔)
Answer – starch (✔)
2. The deficiency of Vitamin A, in the diet, causes a disease known as-
scurvy
rickets
nightblindness. (✔)
beri-beri
Answer – nightblindness. (✔)
3. Iron is essential for-
growth of teeth and bones
formation of haemoglobin (✔)
functioning of the thyroid gland
making muscles strong
Answer – formation of haemoglobin (✔)
4. A child, who has bow legs, is suffering from a deficiency disease, known as-
scurvy
goitre
rickets (✔)
anaemia
Answer – rickets(✔)
5. The deficiency of proteins, in the diet of children, can cause a disease known as-
marasmus
kwashiorkor (✔)
rickets
anaemia
Answer – kwashiorkor (✔)
D. Answer the following questions in brief.
1. Name the important sources of our food.
Answer – Important sources of our food are:
- Plants – fruits, green leafy vegetables, oils, spices, cereals, pulses.
- Animals – milk, eggs, meat, honey.
2. State the importance of carbohydrates in our diet.
Answer – Carbohydrates in our diet are a source of energy. They provide energy to do various works and also for proper functioning of all the organs.
3. Name the vitamin whose deficiency causes the disease of-
(a) nightblindness.
Answer – Vitamin A
(b) beri-beri
Answer – Vitamin B
(c) scurvy
Answer – Vitamin C
(d) rickets
Answer – Vitamin D
4. Name any three of the minerals needed by our body.
Answer – Three minerals needed by our body are calcium, phosphorus and iron.
5. State the role of calcium in our body.
Answer – The role of calcium in our body is to build healthy bones and teeth.
6. Write the full forms of the terms PEM and PCM.
Answer – PEM – Protein Energy Malnutrition
PCM – Protein Calorie Malnutrition
E. Answer the following questions.
1. Name two sources of each of the following:
(a) Carbohydrates
Answer – Rice, wheat
(b) Proteins
Answer – Pulses, eggs
(c) Fats
Answer – Butter, vegetable oils
(d) Roughage
Answer – Fruits, green vegetables
(e) Vitamin A
Answer – Fruits, yellow vegetables
(f) Vitamin C
Answer – Lemon, orange
2. Name two sources of each of the following:
Describe one test each for detecting the presence of the following in food:
(a) proteins
Answer – Materials Required: Mortar and pestle, test tube, dropper, concentrated nitric acid.
Procedure: Some bean seeds are crushed in a mortar and pestle. A suspension is made using water. A little of the suspension is taken in a test tube very carefully. A drop of concentrated nitric acid is added to it. If the colour of the suspension changes to yellow it indicates the presence of proteins.
(b) starch
Answer – starch- Materials Required: iodine solution, test tube, dropper.
Procedure: The material which is to be tested is taken. Iodine solution is added with the help of a dropper. If it turns blue black, it indicates the presence of starch.
(c) fats
Answer – fats – Materials Required: Paper
Procedure: The given food item is taken and rubbed on a dry paper. If fat is present in it, it will leave a translucent mark on the paper.
3. Why do we need proteins and how do they affect our health?
Answer – We need proteins because they help in building up the developing tissues of a growing child and help in wear and tear of the body tissues at all ages.
Deficiency of proteins lead to diseases like kwashiorkor and marasmus in young children and loss of muscles thus loss of strength in adults.
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.
Answer – X is iron, Y is haemoglobin and Z is anaemia. Iron is required for the formation of haemoglobin and deficiency of iron leads to a disease called anaemia.
5. Deficiency of iodine is more common in mountainous regions. Why?
Answer – Deficiency of iodine is common in mountainous regions because the soil and water are poor in iodine. Whereas people of coastal areas don’t get this problem as they get iodine from sea food they eat.
6. What is a balanced diet? Why should we take a balanced diet?
Answer – A balanced diet is a diet that contains all the nutrients in correct proportion. As it contains all the nutrient so it is important for the proper growth and development of the body.
Value Based Question
Rohini had to go to a remote village for one of her photographic assignments. She observed that a large number of the villagers there had swelling in their neck regions. She advised the villagers to use iodised salt and to include fruits and vegetables in their diet, whenever possible. On her way back, she contacted the relevant authorities and ensured that the villagers get a regular supply of iodised salt.
1. State the values displayed by Rohini.
Answer – Helping, responsible, good advisor, sincere.
2. Iodine is needed for the synthesis of a harmone. Name this harmone and the gland that produces it.
Answer – Iodine is needed for the synthesis of a hormone called thyroxine and the gland that produces it is the thyroid gland.
3. Ask the elders in the family, or the seniors in the school/locality, of any incident in which a person has helped a large number of people in solving, or minimising, general problem. Share your findings with your classmates.
Answer – Write on your own.
Something To Do
List examples of food items, belonging to the different food groups, listed in the following table.
Carbohydrate Rich Food Items – Rice, Potato, Sugar
Protein Rich Food Items – Dal, Beans, Mutton, Fish
Food Items Rich in Fats – Butter, Ghee, Mutton
Dairy Products – Milk, Cued, Cheese, Ghee
Food Items that provide Minerals and Vitamins – Spinach, Orange, Cabbage, Radish, Fish
2. Prepare your own meal plan, by choosing the food items from the above table, so that they form a balanced diet for you.
Breakfast Meal – Chapatti and curry
Lunch Meal – Rice, Dal, Curry, Salad
Dinner Meal – Chapatti and curry Salad
3. Perform a test to find out if there is any starch in the sweets prepared from milk/milk products like curd, etc.
Answer – Perform the iodine test on milk or milk products. Remember that presence of starch in a food is indicated by black-blue colour when iodine tincture is added to food items.