Plant Reproduction

Sexual Reproduction Sexual reproduction involves 2 sex cells called gametes. Involves 2 parents. Offspring are genetically different to parents.

Parts of the Flower

The Sepal The sepal protects the flower when it is a bud.

The Petal The petal protects the internal parts of the flower. Petals are often brightly coloured to attract insects to the flower.

Stamen and Carpel

The Carpel The Carpel is the female part of the flower. The carpel produces an egg cell. The nucleus of the egg cell is the female gamete. Some flowers have more than 1 carpel.

The Stamen The Stamen is the male part of the flower. The stamen produces pollen grains. The nucleus of pollen is the male gamete. Most flowers have a number of stamen.

Parts of The Carpel The Stigma – Where pollen lands. The Style – Connects the stigma to the ovary. The Ovary – Produces the female egg

Parts of The Stamen Anther – Produces Pollen. Filament – Supports the anther

Reproduction in Flowering Plants 5 Stages: Pollination Fertilisation Seed and Fruit Formation Seed Dispersal Germination

Pollination Pollination is the transfer of pollen from the anther of one plant to the stigma of another. Pollination occurs by 2 ways: Insect pollination Wind Pollination

Pollination Petals Stamens Pollen Grains Stigmas Nectaries Flower Part Insect Pollination Wind Pollination Petals Large, Coloured, Scented Small, often green Stamens Inside flower Outside flower Pollen Grains Large, Sticky, Fewer in Number Small, Huge numbers Stigmas Small ,inside flower Feathery, Hang outside flower Nectaries Present, produce nectar Absent, not needed

Pollination by Insect

Pollination by Wind

Fertilisation Fertilisation is the fusion of a male gamete nucleus with a female gamete nucleus to form a zygote.

Seed Formation After fertilisation the fertilised ovule/egg forms a seed. The ovary swells to form a fruit. The fruit protects the seed and allows the seed to be carried away.

Seed Dispersal Seeds are dispersed to avoid competition. (Sunlight, water, minerals, space) Seeds are dispersed by animals, wind, self dispersal and by water.

Wind Dispersal Seeds are carried away by the wind. i.e. Dandelion, Sycamore.

Animal Dispersal Many fruits are eaten by animals these fruits contain seeds. The seeds are passed out through the animals digestive system unharmed.

Self Dispersal Some plants have pods that explode to disperse their seeds. i.e. Pea

Water Dispersal Some plant have seeds that float and are carried down stream. i.e water lily

Germination Germination is the growth of a seed into a new plant. Seed germination is necessary for the formation of a new plant. Germination requires Moisture, Oxygen and Suitable Temperature.

Germination

The Seed The Seed consists of: Testa – Seed coat Food Supply – Provides energy The Plumule – Young Shoot The Radicle – Young Root

Conditions Necessary for Germination

Asexual Reproduction Only 1 Parent. No Gametes involved. Offspring are genetically the same as the parent. Examples Geranium – Cuttings Strawberries – Runners Daffodil – Modified Bulbs