ICSE Class 7 Biology Important Questions Chapter 5 Nutrition in Animals and Plants

Biology ICSE Class 7 Important Questions Chapter 5 Nutrition in Animals and Plants

Extra Questions

Question 1.
Name the water soluble and fat soluble vitamins.
Answer:
Water-soluble vitamins are Vitamin B and C. Fat soluble vitamins are Vitamin A, D, E and K.

Question 2.
Define food additives.
Answer:
The substances that are added to food to make them more attractive or to increase their weight or to give colour or flavour to food are called food additives.

Question 3.
How is starch different from simple sugar molecules.
Answer:
Starch is made up of many molecules of simple sugar. It cannot be easily absorbed by the body. A simple sugar can be absorbed easily by the body. For example glucose, a simple sugar is given directly to sports person and patients to provide them quick eneigy. Starch has first to be broken down in to simple sugar to provide energy. Starch is a complex molecule of made up of many molecules of simple sugar. So it cannot be used as quick source of eneigy.

Question 4.
How do you test the presence of fats in a food item ?
Answer:
We will take a strip of brown paper. Now we will mb the given food items on it. We will leave it to dry for some time. Now hold the paper against a light source. A translucent spot indicates that the food item contains fats. Fats leave a translucent spot on the brown paper. This shows that the food item contains fats.

Question 5.
Why it is important for young children to have protein in their diet ?
Answer:
Proteins are the nutrients that provide the body with materials for cell growth and repair. These are the main , building material of the cells. Young, growing children consume more energy than babies and old people. Proteins make new cell for the growth of body. Young children grow faster so they need more proteins for their growth. Proteins helps in the growth of their body. For the proper growth of their body, diet containing high proteins is very important.

Question 6.
How is the presence of proteins tested in a food item?
Answer:
Put a small quantity of egg white in a test tube. Now add a few drops of dilute HN03 (nitric acid) to it. Heat the tube gently on the flame. We will bee that the egg white turns yellow. Pour out the acid and let the egg white remain in the test tube. Now we added a few drops of ammonium hydroxide and noted the change in colour. We will see that it turns reddish. This shows that egg white contains proteins.

Question 7.
How is water important for the body ? Give three ways.
Answer:
About 70 percent of the human body is made up of water. It is essential for most of the functions of our body.

• Water act as medium for the chemical changes that occur inside our body.
• It also helps in eliminating waste from the body.
• It regulates the body temperature.
• We should drink. 8-10 glasses of water every day.

Question 8.
Why is it necessary to consume a variety of food items in our diet ?
Answer:
It is necessary to consume a variety of food items in our diet because our body needs different nutrients for growth. Different foods provides different nutrients. By eating different food items we get the nutrients required for our proper growth and functioning of body. If we keep on eating only one type of food items we will get only the nutrient which is provided by that food item. Our body will not get all other nutrients required for proper growth.

It will cause deficiency disease, e.g. Carbohydrates are provided us by rice, wheat etc. which give us energy. Proteins are body building foods, provided by pulses, meat of the cells.etc. Fruits and vegetables provide us vitamins and minerals needed for proper functioning of different organs. So if we lack one or other nutrient in our diet, our body will not work properly. Deficiency diseases are caused due to this. So to avoid deficiency diseases we should take a balanced diet. (The diet which supplies all the nutrients required by our body in right amount.)

Question 9.
Is the balanced diet for a labourer and a child same ? Justify your answer by giving reasons.
Answer:
The balanced diet for a labourer and a child is not exactly same. Both require more energy as labourer has to do more physical work and a child is also growing. The growing children also need proteins at the same time. As their body is growing and proteins are the building materials. Proteins also help in repairing the worn out tissues. The labourer has to do more physical work. For doing the work he needs carbohydrates, which provide them energy.

They don’t need high protein as their body is not growing up. Proteins are needed only to maintain the body tissues. So the protein requirement for the labourer and a child is not same. A labourer needs more calories (2500-4000 per day) and a child needs 2000 calories per day.

Question 10.
What will happen if you consume more calories than your body needs ?
Answer:
When we consume more calories than our body needs, than we will gain weight. If we consume same number of calories that are used up, our weight will remain the same. If we consume more calories we will become obese. Obesity is a condition in which a person’s weight is at least ten percent more than the normal for his or her weight. Such people have a higher risk of meeting with heart attack. So we should consume the calories required by us i.e. according to our needs.

Question 11.
What are insectivorous plants ? How are they different from other green plants ?
Answer:
Insectivorous plants are green and can manufacture their own food but they partially depend on insects for their nitrogen need as they grow in nitrogen deficient soil. Their leaves are modified to trap insects. For example in pitcher plant, the leaf is modified in to a pitcher with a lid. Once an insect enters the pitcher the lid closes and the trapped insects gets digested by juices released from the inner surface. In bladderwort, die leaf segments get modified to form tiny bladder-like structures which trap minute aquatic organisms.

picther plant an insectivorous plant

Other green plants manufacture their own food without depending on insects.

Question 12.
What are symbiotic plants ? Give example.
Answer:
Plants show some special relationships where two plants lie together as if they are parts of the same plants and are of mutual help to each other. These plants are called symbionts. This type of relationship is called symbiosis.
For example : A lichen is made up of a fungus and an alga living together. An alga is a simple green plant with no roots, stems or leaves. Alga can makes its own food and share it with the fungus but is not able to absorb nutrients from soil. The fungus in turn absorbs water and minerals from the surroundings and also protects the alga.

Question 13.
Define nutrition.
Answer:
The process by which an organism obtains food and utilizes the nutrients present in it is called nutrition.

Question 14.
Classify food on the basis of the function it performs in the body.
Answer:

• Body – building food – These are protein rich food. For examples, pulses, nuts, eggs, fish, meat, oilseeds, soyabean, etc.
• Energy-giving food – These are rich in carbohydrates and fats. For example, cereals such as wheat & rice, sugar, oil, ghee, butter, etc.
• Protective food – These are rich in vitamins minerals and water. For example : vegetables and fruits.

Question 15.
Name few examples of sugars or simple carbohydrate and complex carbohydrate.
Answer:
Glucose, fructose, lactose and sucrose are sugars. Cellulose and starch are complex carbohydrates.

Question 16.
Name few proteins present in our body and food.
Answer:
(a) Actin and Myosin are proteins that contract and relax the muscles to produce movement.
(b) Keratin is the main component of our skin and is a protein.
(c) Haemoglobin in blood is also a protein.
(d) Milk contains a protein called casein.

Question 17.
What are essential amino acids ? Why do we need to consume them daily ?
Answer:
Our body can manufacture only 10 out of the 20 amino acids required for producing proteins. The amino acids which the body cannot manufacture and need to be included in our food are called essential amino acids. While fats and carbohydrates can be stored, the body cannot store essential amino acids, which need to be consumed daily.

Question 18.
Name deficiency disease caused by –

1. Vitamin A
2. Vitamin B
3. Vitamin B
4. Vitamin C
5. Vitamin K
6. Calcium
7. Iron

Answer:

1. Night Blindness
2. Beriberi
3. Anaemia
4. Scurvy
5. Haemorrhage
6. Rickets
7. Anaemia

Question 19.
Mention few uses of vitamins and minerals.
Answer:
Uses of vitamines :

• They ensure growth and proper functioning of the body.
• They are required for the body’s metabolism.
• They help in blood clotting, increase immunity, increase formation of blood cells, prevent from cold, help to make bones and teeth stronger, etc.

Uses of minerals :

• They are needed for the proper growth and normal functioning of the body.
• They are needed for the formation of red blood cells and coagulation of blood.
• They are also important for the proper functioning of the nervous system and circulatory system.

Question 20.
List few good food habits.
Answer:
Good food habits : Eat a balanced diet comprising the optimum amounts from all the food groups. Drink adequate amount of water. Eat clean and hygienically cooked food, avoid junk food. Do not overeat or maintain strict dietary control. Eat at regular hours. Wash your hands before eating, rinse your mouth after eating.

Question 21.
Define calorific value of food.
Answer:
The calorific value of food is the amount of energy released during its combustion or oxidation. It indicates how much energy the body can extract from that particular food item.

Question 22.
What factors do the food/energy intake of a body depend on ?
Answer:

• Age – Teenagers and growing children need to eat more protein rich food than babies and old people.
• Work – A person doing more physical work than person with desk job needs more energy.
• Gender – Males need more energy than females of the same age even if workload is same.

Question 23.
Name few food additives.
Answer:
Flavouring agents like edible food colours, fruit essences. Preservatives like vinegar, aCetic acid and malic acid. Fortifiers or enrichers like salt, iodine, sugar, grains and milk.

Question 24.
Name different categories of heterotrophs in animals.
Answer:
Herbivores, carnivores, omnivores, scavengers, decomposers.

Question 25.
Name different categories of heterotrophs in plants.
Answer:
Saprophytes, parasites, insectivorous plants and symbiotic plants.

Question 26.
Give examples of –

• Saprophytic plants
• Parasitic plants
• Insectivorous plants..

Answer:

• Yeast, mushroom, Monotropa, Neotia (an orchid)
• Cuscuta (Dodder), Rafflesia
• Pitcher plant, Venus flytrap, bladderivorL

Question 27.
Name few macronutrients and micronutrients needed by plants.
Answer:
Macronutrients are nutrients needed by plants in large quantities, for example, nitrogen, phosphorous, potassium ami calcium. Micronutrients are nutrients utilized by plants in small quantities, for example, iron, magnesium and zinc.

Question 28.
Fill in the blanks.
(i) Plants store carbohydrates only in the form of …………..
Answer:
Plants store carbohydrates only in the form of starch.

(ii) ………….. is the only form of carbohydrate which can be absorbed in blood after digestion.
Answer:
Glucose is the only form of carbohydrate which can be I absorbed in blood after digestion.

(iii) Fats release …………… the energy given by carbohydrates and act as reserve source of energy.
Answer:
Fats release double the energy given by carbohydrates and act as reserve source of energy.

(iv) Fats belong to a group of substances called ……………..
Answer:
Fats belong to a group of substances called lipids,

(v) Proteins are made up of chains of smaller molecules called ………….
Answer:
Proteins are made up of chains of smaller molecules called amino acids.

(vi) …………… adds bulk to the food and helps in proper bowel movement and prevents constipation.
Answer:
Roughage adds bulk to the food and helps in proper bowel movement and prevents constipation.

(vii) Groups of foods that have similar nutritional properties are referred to as …………..
Answer:
Groups of foods that have similar nutritional properties are referred to as food groups.

(viii) Most food additives have …………. nutritive value.
Answer:
Most food addetives have little or no nutritive value.

(ix) Microorganisms that consume mostly dead remains of plants and animals are called ……………..
Answer:
Microorganisms that consume mostly dead remains of plants and animals are called decomposers.

(x) Phloem transports …………. (and not starch) made in leaves to other plant parts.
Answer:
Phloem transports glucose (and not starch) made in leaves to other plant parts.

(xi) The stem of Cuscuta (dodder plant) develops sucking roots called …………. which absorb nutrition from the
host plant.
Answer:
The stem of cuscuta (dodder plant) develops sucking roots called haustoria which absorb nutrition from the host plant.

ICSE Class 7 Biology Important Questions