Cycles: Plant Reproduction explained

01 The parts of a flower

Each part has one job, and questions ask for the job rather than the name.

A flower cut in half, with four parts labelled.

Anther (Q) — makes and holds the pollen. It is the male part.
Stigma (P) — the sticky top of the female part, where pollen must land.
Ovary (R) — holds the ovules. After fertilisation the ovules become seeds and the ovary becomes the fruit.
Petal (S) — usually large, bright and scented, to attract insects. Wind-pollinated flowers have small dull petals or none, because they do not need to attract anything.

02 Pollination is not fertilisation

This is the distinction the topic is built on, and getting the two words the wrong way round loses marks in every year.

Pollination is pollen being carried from an anther to a stigma. It is transport, and nothing has joined yet.

Fertilisation is the pollen joining the ovule inside the ovary. Only now does a seed begin.

So pollination happens first, and fertilisation only if the pollen reaches the right place. Pollination without fertilisation produces no seed at all.

Four stages in a fixed order. Stop stage 1 and nothing after it happens.

03 How pollen travels

It cannot move by itself, so something carries it — and the flower's features tell you which.

Insects — large bright scented petals, sticky pollen, nectar to attract them. The insect brushes pollen off one flower and onto the next.

Wind — small dull petals or none, feathery stigmas to catch pollen from the air, anthers hanging outside, and large amounts of light pollen.

Self-pollination is pollen reaching a stigma on the same plant; cross-pollination is reaching a different plant of the same kind. Cross-pollination gives more varied offspring.

04 After the seed forms

The ovule becomes the seed and the ovary becomes the fruit around it. Every fruit is a former ovary, which is why fruits have seeds inside.

The fruit then helps with dispersal — fleshy and sweet so an animal eats it, or dry and winged so the wind takes it — which is where this topic hands over to seed dispersal.

So the full ring is: flower → pollination → fertilisation → seed → dispersal → germination → new plant → flower.

05 How to say them

These are words most children have never said out loud, and a word you cannot say is a word you avoid using. Capitals mark the syllable you lean on. Tap the speaker to hear it.

pollinationsaypol-i-NAY-shuhn
Pollen being carried from an anther to a stigma. Transport, not joining.
fertilisationsayfur-ti-ly-ZAY-shuhn
Pollen joining an ovule inside the ovary, which starts a seed.
anthersayAN-thuhmore than oneanthers
The part that makes pollen.
stigmasaySTIG-muhmore than onestigmas
The sticky top of the female part, where pollen must land.
ovarysayOH-vuh-reemore than oneovaries
The part holding the ovules. It becomes the fruit.
ovulesayOV-yoolmore than oneovules
The part that becomes a seed after fertilisation.
nectarsayNEK-tuh
The sweet liquid a flower makes to attract insects.

06 What each level is tested on

The same topic, asked differently as it goes up. The percentage is the share of papers at that level in which it appears.

P5
The parts of a flower and their jobs, pollination and how pollen travels.
Practise P5 Cycles: Plant Reproduction — 10 questions →
55% of P5 papers
P6
Fertilisation, seed and fruit formation, and the whole cycle from flower to new plant.
Practise P6 Cycles: Plant Reproduction — 9 questions →
65% of P6 papers

07 Mistakes worth knowing about

Each of these is wrong. Decide why before you open it.

“Pollination and fertilisation are the same thing.”
Pollination is pollen being carried to the stigma; fertilisation is it joining the ovule. Pollination comes first and may not lead to fertilisation.
“The flower makes the seed.”
The ovule becomes the seed, after fertilisation. The ovary around it becomes the fruit.
“Wind-pollinated flowers have big bright petals.”
Small, dull or absent. Bright scented petals attract insects, and wind needs no attracting.
“Pollen lands on the anther.”
It is made by the anther and must land on the stigma. The two are easy to swap and are marked separately.
“A fruit is not part of reproduction.”
It is the ovary after fertilisation, and it exists to help the seeds disperse.

Now try it

19 questions across 2 levels, marked as you go with the working shown.

P510 questions P69 questions