Living Science Biology Class 7 ICSE Solutions Chapter 5 Nutrition in Animals and Plants

ICSE Living Science Biology for Class 7 Solutions Chapter 5 Nutrition in Animals and Plants

Check Your Progress

State if the following statements are true or false. Correct the statement if it is false.

Question 1.
Hemoglobin in our blood is a protein.
Answer:
True

Question 2.
Vitamins A, D, E and K are water-soluble.
Answer:
False. Vitamins A, D, E and K are Fat-soluble.

Question 3.
The deficiency of iodine in the body cause anaemia.
Answer:
False. Deficiency of iodine in the body cause goitre.

Question 4.
About 70 per cent of the human body is made up of water.
Answer:
True

Question 5.
Roughage can be easily digested by the body.
Answer:
False. Roughage cannot be easily digested by the body.

Question 6.
The deficiency of vitamin C causes rickets.
Answer:
False. The deficiency of vitamin D causes rickets.

Practice Question 1.
Glucose is the only form of carbohydrates that can be absorbed by the blood after digestion.
Answer:
True

Check Your Progress

Answer the questions.

Question 1.
What are the substances that a body needs to live and grow called ?
Answer:
Nutrients

Question 2.
Name the diet that includes all types of nutrients in the right quantities.
Answer:
Balanced diet

Question 3.
What is added to food stuffs to eliminate deficiency disorders among populations ?
Answer:
Fortifiers or enrichers

Question 4.
What are animals that feed on dead animals called ?
Answer:
Scavengers

Question 5.
What is a food chain ?
Answer;
A series of organisms which are linked with each other through a process of eating and being eaten form a food chain.

Check Your Progress

Fill in the blanks.

Question 1.
Factors that affect photosynthesis are ………… and …………
Answer:
Factors that affect photosynthesis are light, water and carbon-dioxide.

Question 2.
Each stomata has two bean-shaped cells called ………… cells.
Answer:
Each stomata has two bean-shaped cells called guard cells.

Question 3.
All plants have a transport system called the ………….. system.
Answer:
All plants have a transport system called the vascular system.

Question 4.
Yeast, mushroom and certain bacteria are ………………
Answer:
Yeast, mushroom and certain bacteria are saprophytes.

Question 5.
…………… is made up a fungus and an alga living together.
Answer:
A lichen is made up a fungus and an alga living together.

A. Tick the most appropriate answer.

Question 1.
Sugar and starch are
a. proteins
b. fats
c. carbohydrates
d. vitamins
Answer:
c. carbohydrates

Question 2.
Starch is made by combination of many molecules of –
a. fatty acids
b. glycerol
c. amino acids
d. sugar
Answer:
d. sugar

Question 3.
In which category of food will you put pulses, legumes ……….. and milk.
a. protective
b. adulterated
c. energy-giving
d. body-building
Answer:
d. body-building

Question 4.
Calcium and phosphorus are required for
a. healthy teeth and bones
b. long and black hair
c. forming haemoglobin
d. healthy nerves and muscles
Answer:
a. healthy teeth and bones

Question 5.
Iodine is found in
a. seafood
b. milk
c. banana
d. spinach
Answer:
a. seafood

Question 6.
Each stoma has two bean-shaped cells called
a. palisade
b. guard cells
c. epidermis
d. phloem
Answer:
b. guard cells

Question 7.
Transport of water in plants takes place through
a. epidermis
b. xylem
c. phloem
d. stomata
Answer:
b. xylem

Question 8.
If iodine turns blue-black when added to a food item, it shows the presence of
a. glucose
b. proteins
c. starch
d. vitamins
Answer:
c. starch

Question 9.
Plants that depend on dead, decaying organic matter are known as
a. carnivores
b. saprophytes
c. parasites
d. scavengers
Answer:
b. saprophytes

Question 10.
Which of the following is an insectivorous plants ?
a. Mistletoe
b. Lotus
c. Pitcher plant
d. Dodder
Answer:
c. Pitcher plant

B. Match the following.

Column A (Nutrients)	Column B (Food sources)
1. carbohydrates	a. fish
2. fats	b. iodized salt
3. proteins	c. green vegetables
4. vitamins	d. ghce
5. mineraIs	e. noodles

Answer:

Column A (Nutrients)	Column B (Food sources)
1. carbohydrates	e. noodles
2. fats	d. ghce
3. proteins	a. fish
4. vitamins	c. green vegetables
5. mineraIs	b. iodized salt

C. Find the odd one out. Give reasons.

Question 1.
proteins, carbohydrates, fats, vitamins, amino acids
Answer:
Amino acids : Amino acids are the smaller molecules that join to form proteins. All other are the complex nutrients of our food.

Question 2.
rice, wheat, soyabean, noodles, bread
Answer:
Soyabean : It is a protein rich food and all other are carbohydrate rich foods.

Question 3.
meat, egg, beans, spinach, milk
Answer:
Spinach. It is iron rich food and all other are phosphorous rich.

Question 4.
butter, cucumber, oil, ghee, almonds
Answer:
Cucumber : All are fatty foods, it is a roughage.

Question 5.
iron, sodium, potassium, iodine, vitamin A
Answer:
Vitamin A : All are minerals except vitamin A.

Question 6.
milk, ghee, vegetable soup, fruit-juice
Answer:
Ghee : It is an energy giving food while rest are protective foods. –

D. Differentiate between

Question 1.
carbohydrates and fats.
Answer:
Carbohydrates :

• These are quick source of energy.
• Provides less energy than fats.

Fats :

• These are richest source of energy but not quick source of energy.
• Provides more energy than carbohydrates.

2. proteins and vitamins.
Answer:
Proteins :

• They are required in large quantity.
• They are body building material of the cells
• Proteins are the main structural components of animal and plant cells.

Vitamins :

• hey are required in small quantity.
• They are protective foods.
• Vitamins keep the body
• healthy and help in the proper growth of the body.

3. autotrophs and heterotrophs
Answer:
Autotrophs :

• Organisms which make their own food are called autotrophs
• All green plants are autotrophs.
• They have chlorophyll.

Heterotrophs :

• Organisms which obtain their food directly or indirectly from plants are called heterotrophs.
• Non-green plants and animals including human beings are heterotrophs.
• They lack chlorophyll.

4. parasites and saprophytes
Answer:
Parasites

• These plants feed on food made by other green plants.
• They have haustoria (sucking roots)
• Example : Cascuta, Rafflesia

Saprophytes :

• They feed on dead and decaying organic matter.
• They do not have haustoria (sucking roots)
• Example : Yeast, mushroom ,

5. parasites and symbionts
Answer:
Parasites :

• Parasites feed on food made by other green plants.
• Parasites obtain nutrition from host plant which is in loss.
• example – Cascuta, Rafflesia

Symbionts :

• These plants show special relationships of mutual benefits.
• Symbionts live together as if they are parts of the same plant and are of mutual help to each other.
• Lichen is symbiont made up of a fungus and an alga living together.

Question 6.
macronutrients and micronutrients
Answer:
Macronutrients

• Nutrients required in large quantities are called macronutrients.
• For examples – Nitrogen phosphorus and potassium

Micronutrients:

• Nutrients required in small quantities are called microniitrients.
• For example – iron and copper.

E. Answer the following in short.

Question 1.
What are nutrients ? Why does our body require nutrients ?
Answer:
The substances that a body needs to live and grow are called nutrients. Nutrients provide us energy, material for the repair of tissues. They keep us healthy. Our body require nutrients to cany out all functions like running, jumping, walking and swimming. Nutrients also help in repairing of tom out tissues and also keep us healthy.

Question 2.
What is holozoic mode of nutrition ?
Answer:
The method of obtaining food directly or indirectly from plants is called holozoic mode of nutrition or heterotrophic nutrition. Nongreen plants and animals including human beings are heterotrophs.

Question 3.
List the five main nutrients which our body needs.
Answer:
The five main nutrients which are body needs are :
(a) carbohydrates
(b) fats
(c) proteins
(d) vitamins
(e) minerals.

Question 4.
List five food items that are rich in protein.
Answer:
Food items that are rich in proteins are :
(a) Egg white
(b) peanuts
(c) meat
(d) Mi
(e) peas
(f) pulses
(g) chicken

Question 5.
Define deficiency disease.
Answer:
The diseases caused due to deficiency of sufficient amount of certain nutrients in the diet, are called deficiency diseases.

Question 6.
What is roughage ?
Answer:
Fruits and most vegetables which adds bulk to the food and cannot be digested by our digestive system, are called roughage.

Question 7.
List four food items which belong to the pulses and meat group.
Answer:
The food items that contain proteins belongs to pulse and meats group. These are chicken, fish, egg, peas, nuts.

Question 8.
What is a balanced diet ?
Answer:
The diet which supplies all the nutrients in the right quantity according to the requirement of the body, is called a balanced diet.

Question 9.
Define obesity.
Answer:
The condition in which person’s weight is at least ten percent more than the normal for his or her height is called obesity.

Question 10.
What are food fads ? Give an example.
Answer:
Sometimes people llels that costlier and hard to get food is more nutritious This is called a food-fad. Lack of knowledge leads to wrong beliefs about certain foods. If we compare the nutritive value of two food items like grapes and spinach, spinach has more proteins, fats, minerals, vitamins than grapes. Yet people prefer to have the more expensive grapes though spinach is more nutritions than grapes.
Some misconceptions about a few foods are as :

1. White eggs are better than brown ones
No – Both types of eggs have the same amount of nutrients.

2. Fish is brain food. It makes you intelligent.
No- Fish is just a protein rich food. It has got nothing to do with intelligence.

3. Eating ladies finger makes you good in mathematics.
No- There is no relationship between eating ladies finger and being good in mathematics.

Question 13.
Define food additives.
Answer:
The substances that are added to food to make them more attractive or to increase their Weight, to give colour or flavour to food are called food additives.

Practice Question 1.
Define food chain.
Answer:
A series of organisms which are linked with each other through a process of eating and being eaten form a food chain.

F. Answer the following in detail.

Question 1.
List the main functions of carbohydrates, fats and proteins.
Answer:
The main functions of carbohydrates are :
1. These are a quick source of energy for the body.
2. These act as reserve source of energy as excess of carbohydrates are stored in the body as glycogen and fats.

The main functions of fats :
1. These are the richest source of energy.
2. They help in the absorption of vitamins A, D, E and K which are fat soluble vitamins.
3. They provide padding around vital organs in our body.
4. Fats in skin provide protection against cold.

The main functions of proteins are :
1. They are essential for building and maintaining body tissues.
2. These are found in many enzymes and hormones.
3. These are the main structural components of plant and animal cells.

Question 2.
How would you test the presence of starch in green leaves ?
Answer:
Take a green leaf from a healthy plant. First we will bleach it to remove the green colour of the leaf by boiling it first in water and then in alcohol. Wash it with cold water. Now add a few drops of iodine to it. We will see that the leaf turns blue-black in colour. This is because of the presence of starch in it.

Question 3.
How many serving of each food group should be eaten to make sure that one eats a balanced diet ?
Answer:
Groups of food that have similar nutritional properties are referred to as food groups. There are six basic groups based on their nutritional properties.

These are :
(a) milk and cheese group
(b) Pulses and meat-group
(c) vegetable group
(d) fruit group
(e) fats and oil group
(f) grain group.
A balanced diet of each days includes a minimum number of servings from each group. They are as follows :

• Three servings from the milk and cheese group
• Two servings from the pulses and meat group.
• Three to four serving from vegetable group.
• two servings from the fruit group
• four servings from the grain groups.

Question 4.
How do plants obtain their food ? What are the raw materials required by green plants to make food ?
Answer:
Plants are autotrophs as they make their own food by the process of photosynthesis. Photo means light and synthesis means building up. This method is called autotrophic nutrition.
Raw materials :
Raw materials for photosynthesis are :
(a) Carbondioxide
(b) Water
(c) Sunlight – as the source of eneigy.

Chlorophyll (green pigment) in the cells of a leaf is capable of absorbing sunlight and using this energy.
CO₂ is taken in from the air by the leaf through stomata and water is absorbed by roots is converted to glucose. Oxygen is released as the by product.

Question 5.
Explain the functioning of stomata with the help of a labelled diagram.
Answer:
Stomata are present on the lower surface of the leaves and green stems of plants. Stomata are the small openings (singular-stoma) through which the gases are exchanged. Each stomata has two kidney-shaped (bean shaped) cells called guard cells. The inner walls of the guard cells are thicker than the outer walls. When the guard cells are full of water, they swell and bulge outwards and the stomata open. When the guard cells lose water, they lose their turgidity and the stomata close.

Stomata remain open during day and closes at night

G. Answer the following questions.

Question 1.
Take some boiled potatoes, french fries, baked ‘ potatoes and potato chips. Rub a small amount of each of these on a brown paper. Write the name of \ each item below the spot you rubbed. Wait for five minutes for the spot to dry. Hold the paper towards light and record your observation. Which type of potatoes contain fat ? If you are on a low fat diet, which type of potatoes would you eat ? Why?
Answer:
French fries and potato chips contain fat. On a low fat diet, we would eat boiled or baked potato as they do not have any fat like oil, ghee or butter in them.

Question 2.
Pick up a wrapper or a packet of wafers, chips, or any other instant food. Read the label showing its nutrition facts. Compare it with the label on a packet ; of biscuits or a cereal like oats. Which should you eat more often ?
Answer:
We should eat cereal like oats and biscuits more as it is healthy as compared to other junk items.

H. Mayank made some mistakes while making the food web. Correct them.

Answer:

Living Science Biology Class 7 ICSE Solutions