In this lesson we are going to learn about the growth of a seed into a young plant which is called germination.
Structure of a seed
There are three main parts in a seed.
- Food Store (Stored food)
- Seed coat
Embryo – This is a tiny plant inside a seed.
Foodstore – These are food stored by the parent plant.
Seed coat – This is the hard cover around the embryo and foodstore.
The embryo rests inside the seed until the conditions are right for it to start to grow.
E.g. – Likewise some seeds can stay in this resting state for hundreds of years.
Starting to grow
What is ‘germination’?
The growth of a seed into a young plant or a seedling is called germination.
What are 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. The oxygen in the air helps the baby plant burn the food packed inside the seed.
- Burning the food produces energy. The baby plant uses the energy to grow.
- A tiny root grows downwards and a shoot begins to grow upwards.
- The shoot develops and reaches toward the light while the root system develops deep in the soil.
- Tiny leaves sprout at the end of the shoot letting Photosynthesis to take place.
- The primary root grows longer and thicker together with the secondary roots. The leaves grow larger.
- More and more leaves grow and the stem becomes thicker and stronger.
January 8, 2015