Seeds and fruit

A pollen grain starts to grow if it lands on the stigma of a flower of the correct species. A pollen tube grows through the tissues of the flower until it reaches an ovule inside the ovary. The nucleus of the pollen grain (the male gamete) then passes along the pollen tube and joins with the nucleus of the ovule (the female gamete). This process is called fertilisation.

The slideshow explains what happens:

Plant reproduction: a pollen tube comes out of the ovary. Pollen grains are above the pollen tube.

A pollen grain is transferred from one flower to another. A pollen tube grows from the stigma to the ovary.

After fertilisation, the female parts of the flower develop into a fruit:

  • the ovules become seeds
  • the ovary wall becomes the rest of the fruit

Seeds

A seed has three main parts:

  • embryo – the young root and shoot that will become the adult plant
  • food store – starch for the young plant to use until it is able to carry out photosynthesis
  • seed coat – a tough protective outer covering
Component parts of fertilised ovule as it turns into seed.  Seed coat around outside, large food store in the middle.  Embryo of new plant beginning to grow within seed coat.A cross-section through a seed