Class 4 Science Chapter 1 Food Preparation in Plants

 Class 4 Science Chapter 1 Food Preparation in Plants

1. Tick (✓) the right answer
2. The broad flat part of the leaf is called ____________.

Answer: (b) stalk

2. Which of the following living organisms make their own food?

Answer: (c) Green plants

3. The chlorophyll in leaves gives them ____________ colour.

Answer: (b) green

4. Food made by plants is in the form of ____________.

Answer: (c) glucose

5. Plants get light from the ____________ for preparing food.

Answer: (d) Sun

1. Fill in the blanks with appropriate words
2. Extra food is stored in the form of ____________ in plants.

Answer: starch

2. ____________ transport food, water and minerals to and from the leaf.

Answer: Veins

3. Roots absorb water and minerals from the ____________.

Answer: soil

4. ____________ help the plant to breathe.

Answer: Stomata

1. Unscramble the letters
2. STHESITOPHOYN

Answer: PHOTOSYNTHESIS

2. AMTOSTA

Answer: STOMATA

3. LROPHYLCOHL

Answer: CHLOROPHYLL

4. CHARTS

Answer: STARCH

1. Match the following

Column A	Answer	Column B
1. Leaves	→	(d) Food factory of a plant
2. Chlorophyll	→	(e) Green colour
3. Roots	→	(a) Absorb water and minerals
4. Stomata	→	(c) Tiny holes in leaves
5. Photosynthesis	→	(b) Sunlight, water and carbon dioxide

1. Short answer questions
2. Define photosynthesis.

Answer:
Photosynthesis is the process by which green plants make their own food in the presence of sunlight, water, carbon dioxide and chlorophyll.

2. What is the role of stomata in photosynthesis?

Answer:
Stomata are tiny pores in leaves. They help in exchange of gases. During photosynthesis, carbon dioxide enters the leaf through stomata and oxygen is released through them.

3. What is chlorophyll?

Answer:
Chlorophyll is a green substance present in leaves. It helps the plant absorb sunlight for making food.

4. What is a food chain?

Answer:
A food chain is a chain of living organisms in which each organism depends on another organism for food.

Example: Grass → Deer → Lion

1. Long answer questions
2. Draw a well-labelled diagram of a leaf and write about parts of a leaf.

Answer:
A leaf has the following parts:

• Stalk / Petiole – It attaches the leaf to the stem.
• Leaf blade / Lamina – The broad flat green part of the leaf.
• Main vein / Midrib – Runs along the middle of the leaf.
• Side veins – Branch out from the main vein and carry water, minerals and food.
• Stomata – Tiny pores on the underside of the leaf that help in breathing and gas exchange.

2. What are the raw materials needed by a plant to make food? How does plant obtain these raw materials?

Answer:
The raw materials needed by a plant to make food are:

• Water
• Carbon dioxide
• Sunlight
• Chlorophyll

How plants obtain them:

• Water and minerals are absorbed from the soil by the roots.
• Carbon dioxide is taken in from the air through stomata.
• Sunlight comes from the Sun.
• Chlorophyll is present in the green leaves.

3. Write about the process of photosynthesis.

Answer:
Photosynthesis is the process by which green plants make their own food.

Process of photosynthesis:

1. Chlorophyll present in leaves absorbs sunlight.
2. Carbon dioxide from the air enters the leaves through stomata.
3. Roots absorb water and minerals from the soil.
4. Water and minerals reach the leaves through the stem.
5. In the presence of sunlight and chlorophyll, the leaves prepare food.
6. Oxygen is released through stomata.

The food prepared is glucose, and extra food is stored as starch.

4. How do plants use their food?

Answer:
Plants use their food in the following ways:

1. To get energy.
2. For growth.
3. To repair damaged cells and tissues.
4. Extra food is stored in the form of starch in roots, stems, leaves, fruits or seeds.

5. How are plants and animals interdependent?

Answer:
Plants and animals depend on each other in many ways:

• Plants make food and provide food to animals.
• Plants release oxygen during photosynthesis, which animals and humans need for breathing.
• Animals breathe out carbon dioxide, which plants use to prepare food.
• Animals also help in maintaining balance in nature.

So, plants and animals are interdependent.

1. HOTS questions
2. What will happen if in the food chain, all the carnivores become herbivores?

(There will be: (a) too many plants (b) too many animals (c) no effect)

Answer: (b) too many animals

Reason:
If carnivores also start eating plants, the number of plant-eating animals will increase. This will disturb the food chain and create imbalance.

2. Why green plants are beneficial for us?

Answer:
Green plants are beneficial for us because:

• they make food,
• they give us oxygen for breathing,
• they provide food directly or indirectly to animals and humans,
• they help maintain the balance of nature.

3. When do you think photosynthesis is carried out in plants: during the day, during the night or during both? Why?

Answer:
Photosynthesis is carried out during the day because sunlight is necessary for plants to make food.

4. What will happen if a green plant is kept in a closed, dark room for a long time?

Answer:
If a green plant is kept in a closed, dark room for a long time, it will not be able to make food because it does not get sunlight. Gradually, the plant will become weak and may die.