What do plants need to grow?

Plants need light to grow well. This is because plants need light to make food in a process called photosynthesis.

During photosynthesis, plants use light energy and the raw materials carbon dioxide and water to make food.

The carbon dioxide is obtained from the air while water is absorbed through the roots of the plants from the soil or surroundings. The food produced is in the form of sugar. A gas called oxygen is given out in the process.

Most leaves are green because they contain a green pigment called chlorophyll which is able to trap sunlight. The light energy trapped by the chlorophyll is used to make food during photosynthesis.

Qs. The water which plants need to make food is absorbed by the roots of the plants from the surroundings. How does the carbon dioxide which plants need for photosynthesis get into the plants?

stoma

There are many tiny openings called stomata (singular: stoma) which allow gases to enter or leave through the underside of a leaf. That is why you see gas bubbles coming out from the underside of the leaf when you soak the leaf is warm water.

Carbon dioxide from the air enters the leaf through the stomata. The carbon dioxide is used for photosynthesis. The oxygen produced during photosynthesis is used for an essential life process called respiration.

Excess oxygen leaves through the stomata. Plants lose water in the form of water vapour to the surroundings through the stomata too.

The food produced by plants during photosynthesis becomes the energy source for animals which feed on the plants directly or indirectly.

Plants themselves make use of the light energy from the Sun to make food. Thus, the energy stored in plants and animals is derived from the Sun.