Reproduction in Plants

The flower — an angiosperm's reproductive structure

In angiosperms (flowering plants), the flower is the organ of sexual reproduction. It contains male parts (the stamen: anther + filament) that produce pollen, and female parts (the carpel: stigma + style + ovary) that produce ovules.

Pollination

Pollination is the transfer of pollen from an anther to a stigma. This can happen in two ways:

Self-pollination — pollen transfers within the same flower or plant.
Cross-pollination — pollen transfers between flowers on different plants, usually carried by wind or by pollinators such as insects, birds, or bats.

Fertilisation, seeds, and fruit

After pollination, a pollen grain grows a tube down the style to reach an ovule in the ovary — fertilisation occurs when the male and female sex cells fuse. The fertilised ovule develops into a seed, and the ovary develops into a fruit, which protects the seed(s) and often aids in dispersal.

Seed dispersal — moving seeds away from the parent plant — reduces competition for resources and helps the species colonise new areas. Dispersal methods include wind (light, winged seeds), animals (fleshy fruit that's eaten, or hooked seeds that stick to fur), and water.

Asexual (vegetative) reproduction

Many plants can also reproduce asexually, producing offspring that are genetically identical to the parent, without pollination or fertilisation. This happens through structures such as runners, bulbs, tubers, or rhizomes growing into new, independent plants.

	Sexual reproduction	Asexual (vegetative) reproduction
Involves	Pollination + fertilisation of sex cells	A single parent, no fertilisation
Offspring	Genetically varied	Genetically identical to parent
Example structure	Flower → seed	Runner, bulb, tuber, rhizome

Answer in your exercise book.

Question 1 · (4 marks)

Name the male and female parts of a flower, including their sub-parts.

Question 2 · (2 marks)

Distinguish between self-pollination and cross-pollination.

Question 3 · (3 marks)

Describe what happens during fertilisation in a flowering plant, and what the ovule and ovary each develop into.

Question 4 · (3 marks)

Name THREE methods of seed dispersal, with an example adaptation for each.

Question 5 · (3 marks)

Explain the difference between sexual and asexual (vegetative) reproduction in plants, in terms of genetic variation in the offspring.

Question 6 · (6 marks)

A researcher sowed 100 seeds from the same tree species at each of four distances from a parent tree, and recorded how many seedlings survived after one month:

Distance from parent tree (m)	Seeds sown	Seedlings survived
0.5	100	8
2	100	35
5	100	62
10	100	68

(a) Calculate the percentage seedling survival at each of the four distances. Show your working. (3 marks)
(b) Describe the trend shown by the data as distance from the parent tree increases. (1 mark)
(c) Suggest a reason, in terms of competition for resources, why seedling survival is much lower close to the parent tree. (2 marks)

The flower — an angiosperm's reproductive structure

Pollination

Fertilisation, seeds, and fruit

Asexual (vegetative) reproduction

Flower Structure Explorer