Plant

• What is plant asexual reproduction?

  New offspring are produced by a single parent organism without the production of seeds or spores

  The offspring are genetically identical to the parent plant and to each other.
• Plant sexual reproduction

  The part of the plant that reproduces is the flower.

  Involves a process called pollination to enable fertilisation, requires a male and female gamete.

  The male gamete is contained in pollen, produced by the anther which is held up by the filament. These are parts of the stamen.

  The female gamete is the ovum contained in the ovule inside the ovary. These are parts of the carpel.
• Carpel(female organ)

  Contains stigma, style and ovary
• Stigma

  Sticky for pollen to attach
• Style

  Holds up the stigma
• Ovary

  Contains the ovules
• Ovule

  Contains the ovum(egg), the female gamete
• Stamen(male organ)

  Made up of the anther and filament
• Filament

  Holds the anther up
• Anther

  Produces pollen, the male gamete
• Petal

  Brightly coloured and sweet smelling to attract insects
• Sepal

  Protects the flower in bud
• Receptacle

  The flower stalk where the parts of the flower are attached
• For pollination to occur

  the pollen grains need to move from the anther to the stigma
• Self-pollination

  When the pollen lands on the stigma of the same flower or different flower of the same plant
• Cross-pollination

  Pollen from the anthers of a flower lands on the stigma of another flower on a different plant of the same species.

  Results in more genetic variation
• Ways pollen can be spread

  Carried by wind

  Animals

  Insects such as bees and butterflies or small birds as they collect nectar
• After pollination

  A pollen tube grows out of the pollen grain and grows down the style

  The pollen nucleus then moves down the tube

  The pollen nucleus fuses with the ovum(fertilisation)

  A zygote is produced which develops into an embryo which is stored in a coat , the seed

  The ovule becomes a seed and the ovary and the rest of the carpel becomes fruit
• Why are seeds dispersed

  So they can grow without too much competition
• Plants compete for

  Light

  Water

  Minerals

  Space to grow
• Ways that seeds are dispersed

  Blown by wind

  Exploding out of pods

  Some have hooks that enable them to be carried away

  If fruits are eaten by animals the seed may be egested in faeces and may germinate in fertile soil

  If buoyant will float away in water