Plant reproduction

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

Learn

Plant reproduction

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.

Introduction to plants and reproduction

Flower structure

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

Pollination

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:

 Feature Insect-pollinated Wind-pollinated
Petals  Large and brightly coloured - to attract insects Small and often dull green or brown - no need to attract insects  
Scent and nectarUsually scented and with nectar - to attract insectsNo scent or nectar - no need to attract insects
Number of pollen grainsModerate - insects transfer pollen grains effecientlyLarge amounts - most pollen grains are not transferred to another flower
Pollen grainsSticky or spiky - sticks to insects wellSmooth and light - easily carried by the wind without clumping together
AnthersInside flower, stiff and firmly attached - to brush against insectsOutside flower, loose on long filaments - to release pollen grains easily
StigmaInside flower, sticky - pollen grains stick to it when an insect brushes pastOutside 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:

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

1 of 3

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

Dispersal

Plants compete with each other for factors such as:

  • light
  • water
  • space
  • 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.

There are a number of different ways plant seeds can be dispersed

The table describes the most common methods of seed dispersal:

 Method Detail Examples
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 undamagedTomato, plum, raspberry, grape
Animals (outside)Fruits have hooks that attach them to the fur of passing animalsGoose grass, burdock
Self-propelledHave a pod that bursts open when ripe, throwing the seeds away from the plantPea pod

Practise

Try the activities below to test your knowledge.

Activity 1

Plant reproduction quiz

Test how much you know about plant reproduction in this quiz.

Activity 2

Plant reproduction activity

Try structure and function of a flower activity from Beyond. You can use a paper and pen if you don't have a printer.

Structure an function of a flower

There's more to learn

Have a look at these other resources around the BBC and the web.

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