Seeds & Germination

This lesson covers:

  1. The structure of a seed
  2. What 'germination' means
  3. The conditions required for a seed to germinate 

Structure of a seed

Diagram showing the structure of a seed with labels for embryo root and shoot, food store, and seed coat.

1Embryo root and embryo shoot – the young root and shoot that will become the adult plant. You may see this called 'embryo root and shoot'.

2Food store – a store of lipids and starch for the young plant to use until it is able to carry out photosynthesis.

3Seed coat – a tough protective outer covering.

Illustration showing the process of seed germination from seed to young plant.

Germination is a process, controlled by enzymes, in which the seed begins to develop into a new young plant.


Three main factors are needed for successful germination:

Illustration of a seed with a water droplet symbolising the role of water in germination.

Water - causes the seed to swell, and activates the enzymes required for growth.

Illustration of oxygen molecules, essential for aerobic respiration during germination.

Oxygen - required for aerobic respiration, which provides the energy needed for the plant to grow.

Illustration of a seed and a thermometer indicating the importance of temperature in germination.

Warmth - increases the rate of enzyme activity, which in turn increases the rate of growth. However, very high temperatures can denature enzymes and so may slow or stop its growth.

What are the 3 main factors needed for successful germination? 

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What substance do seeds require in order to swell and activate their enzymes?

Water

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Why do seeds require oxygen in order to germinate? 

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Will plants germinate at very high temperatures (e.g. 60°)? Why?

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