Photosynthesis Class 10th Important Questions with Answers Science

Photosynthesis mainly happens in the leaves of the plant, inside parts called chloroplasts.

Inside the leaves, there are tiny structures called chloroplasts, which contain a green pigment called chlorophyll. Chlorophyll captures sunlight and uses its energy to turn carbon dioxide (from the air) and water (from the soil) into glucose (a type of sugar) and oxygen.

Plants need four main things for photosynthesis:

1. Sunlight – It provides the energy needed to drive the chemical reactions.
2. Carbon dioxide (CO₂) – Plants take it from the air through tiny openings in their leaves called stomata.
3. Water (H₂O)– Plants absorb it from the soil through their roots.
4. Chlorophyll – This green pigment, found in chloroplasts, captures the sunlight and helps convert carbon dioxide and water into food.

Photosynthesis is very important for us because it gives us two things we cannot live without:

1. Oxygen – During photosynthesis, plants release oxygen into the air, which we need to breathe and survive.
2. Food – Plants make their own food through photosynthesis, and they are the base of the food chain. We eat plants directly or eat animals that eat plants.

Without photosynthesis, there would be no oxygen to breathe and no food to eat. It also helps keep the balance of carbon dioxide in the air.

The raw materials for photosynthesis are:

1. Carbon dioxide (CO₂)– Taken from the air through small pores in leaves called stomata.
2. Water (H₂O) – Absorbed from the soil by the plant's roots.
3. Sunlight – Provides the energy needed for the process.
4. Chlorophyll – The green pigment in leaves that captures sunlight (not a material taken from outside, but necessary for the process).

Stomata open during the day and close at night because:

During the day, plants need sunlight for photosynthesis. When stomata open, they allow carbon dioxide (CO₂) to enter the leaf, which is needed for making food.

At night, there is no sunlight, so photosynthesis cannot happen. To save water and prevent water loss through evaporation, the stomata close.

In simple words:
In day time stomata open for carbon dioxide and photosynthesis.
In night stomata close to save water.