Horrible Science: Dr Big Brain and plants

What do plants need to grow?

Image of Dr Big Brain's mum sitting in front of some plants pointing forward. She is wearing glasses, a light blue coat and purple tights and shoes.

Plants need several things to stay alive and grow. These include light, water, air and nutrients from the soil. They also need enough space to grow.

Plants use energy from sunlight to make their own food in a process called photosynthesis. This food helps plants grow strong stems, leaves, flowers and fruit.

Without the right conditions, plants may grow slowly, become weak or stop growing altogether.

Watch: Dr Big Brain's Mum

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Explore how plants use sunlight to grow when Dr Big Brain’s Mum comes to visit his evil lair.

How does photosynthesis help plants survive?

Photosynthesis is the process plants use to make food. It happens mainly in the leaves.

During photosynthesis:

sunlight provides energy
carbon dioxide is taken in from the air
water is absorbed through the roots

These are used to make sugars, which give the plant energy to grow. Oxygen is released back into the air as a result of the process.

Photosynthesis is essential for life on Earth because it supports plant growth and provides oxygen for animals to breathe.

How do some plants reproduce without seeds?

Some plants can reproduce asexually, without the need for seeds. This means new plants grow from parts of the parent plant, such as cuttings, bulbs or runners.

Plants grown this way are clones of the parent plant. A clone is a copy of the parent plant. It has the same genetic information inside it, so it will grow to look and behave like the parent plant.

Many familiar fruits, including apples, are grown using this method so the new plants grow in the same way as the parent plant. This type of reproduction helps people grow reliably good crops of the same size, shape and taste.