In this lesson we are going to learn about the growth of a seed into a young plant which is called germination. Learn the lesson and try the ‘Seed Germination Quiz’ at the end to check your knowledge.
Structure of a seed
First of all, let’s learn the three main parts in a seed.
- Food Store (Stored food)
- Seed coat
Embryo – This is a tiny plant inside a seed.
Food store – These are food stored by the parent plant. Also, known as stored food.
Seed coat – This is the hard cover around the embryo and also, the food store.
Example of the structure of a seed
The embryo rests inside the seed until the conditions are right for it to start to grow.
E.g. – Similarly, some seeds can stay in this resting state for hundreds of years.
What is germination?
The growth of a seed into a young plant or a seedling is called germination.
Examples of the conditions (factors) that plants need to germinate
- Air (oxygen)
Steps of Germination
- When conditions are right the seed starts to take in water.
- As water is taken in, the seed swells bigger and bigger until the coat splits apart.
- Air can then get to the seed. So, the oxygen in the air helps the baby plant burn the food packed inside the seed.
- Burning the food produces energy. As a result, the baby plant uses the energy to grow.
- A tiny root grows downwards whereas a shoot begins to grow upwards.
- The shoot develops and reaches toward the light while the root system develops deep in the soil.
- The cotyledon later become the first leaves of the seedling when the seed germinates.
- Tiny leaves sprout at the end of the shoot letting Photosynthesis to take place. These are called foliage leaves. They give the baby plant energy, until it gets its own green leaves to photosynthesise.
- The primary root grows longer and thicker together with the secondary roots. The leaves grow larger.
- Finally, More and more leaves grow and the stem becomes thicker and stronger.
Example of the steps of germination