Home learning focus
Flowers are important in plant reproduction. They produce male sex cells and female sex cells. These must meet for reproduction to begin, a process called pollination. Learn about plant reproduction.
This lesson includes:
- two videos to help you learn about plant reproduction
- two practise activities to help reinforce learning
Plants produce flowers to make seeds. To make a seed, a flower must first be pollinated. Watch this film to learn how plants produce seeds. Be sure to make some notes while you watch the film.
Parts of a flower
The flower is the reproductive organ of many plants.
- Petals may be brightly coloured to attract insects
- Anthers produce male sex cells (pollen grains)
- Stamens are the male parts of the flower (each consists of an anther held up on a filament)
- Stigma are the top of the female part of the flower which collects pollen grains
- Ovary produces the female sex cells (contained in the ovules)
- Nectary produce a sugary solution called nectar, which attracts insects
- Sepals protect the unopened flower
During plant reproduction, pollen grains need to move from the anther of one flower to the stigma of another flower. This is called pollination.
Insects can pollinate flowers, and so can the wind. Insect-pollinated flowers are different in structure from wind-pollinated flowers.
This table describes some differences:
|Petals||Large and brightly coloured - to attract insects||Small and often dull green or brown - no need to attract insects|
|Scent and nectar||Usually scented and with nectar - to attract insects||No scent or nectar - no need to attract insects|
|Number of pollen grains||Moderate - insects transfer pollen grains effeciently||Large amounts - most pollen grains are not transferred to another flower|
|Pollen grains||Sticky or spiky - sticks to insects well||Smooth and light - easily carried by the wind without clumping together|
|Anthers||Inside flower, stiff and firmly attached - to brush against insects||Outside flower, loose on long filaments - to release pollen grains easily|
|Stigma||Inside flower, sticky - pollen grains stick to it when an insect brushes past||Outside flower, feathery - form a network to catch drifitng pollen grains|
We depend upon pollination by insects (including the honey bee) for many of our crops. Without them, the security of our food production would be threatened.
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 below explains what happens:
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
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
Plants compete with each other for factors such as:
- minerals in the soil
Seeds must be dispersed or spread away from each other and from the parent plant. This is to reduce competition between the parent plant and the new plants.
The table describes the most common methods of seed dispersal:
|Wind||Seeds have lightweight parts, wings or parachutes||Dandelion, sycamore|
|Animals (inside)||Brightly coloured and tasty fruits contain seeds with indigestible coats, so that the seeds pass through the animal’s digestive system undamaged||Tomato, plum, raspberry, grape|
|Animals (outside)||Fruits have hooks that attach them to the fur of passing animals||Goose grass, burdock|
|Self-propelled||Have a pod that bursts open when ripe, throwing the seeds away from the plant||Pea pod|
Try the activities below to test your knowledge.
Plant reproduction quiz
Test how much you know about plant reproduction in this quiz.
There's more to learn
Have a look at these other resources around the BBC and the web.