Last reviewed: 10 November 2026
Updated November 2026. These Grade 9 fertilisation, fruit formation and seed dispersal notes explain what happens after pollination in a flowering plant, how fruits and seeds form, and how fruits and seeds are dispersed by animals, wind, water and self-dispersal (explosive mechanism). After a pollen grain lands on the stigma, a pollen tube grows down to the ovule, fertilisation takes place, the ovule becomes a seed and the ovary becomes a fruit.
The questions are original practice for Kenyan junior school learners, not an official paper. For other Grade 9 science topics, see the Grade 9 Integrated Science revision guide and the Grade 9 notes hub. Flower parts and pollination are covered in our parts of a flower and pollination notes.
On this page
What the Grade 9 Curriculum Covers
Reproduction in plants is a sub-strand under Living Things and the Environment in the Kenya Institute of Curriculum Development’s Grade 9 Integrated Science design. It covers functions of flower parts, pollination and adaptations to wind and insect pollination, fertilisation, seed and fruit formation, and fruit and seed dispersal. The design notes that factors promoting or hindering self-pollination are not required. It is listed on the KICD Grade Nine curriculum designs page. This page covers fertilisation, fruit formation and dispersal.
Fertilisation in Flowering Plants
- A pollen grain lands on a stigma of the same species during pollination.
- A pollen tube grows from the pollen grain down through the style towards the ovary.
- The tube enters the ovule, and a male nucleus fuses with the egg cell. This fusion is fertilisation and forms a zygote.
The sequence follows OpenStax Biology’s section on pollination and fertilization, which also describes double fertilisation in flowering plants. At Grade 9 level, the key idea is that a male nucleus from pollen joins the female egg cell in the ovule.
Seed and Fruit Formation
| Flower part | Becomes |
|---|---|
| Zygote | Embryo of the seed |
| Ovule | Seed |
| Integuments (ovule coverings) | Seed coat (testa) |
| Ovary | Fruit |
| Ovary wall | Fruit wall (pericarp) |
Petals, stamens and often the style and stigma usually wither and fall off. A fruit has two scars: one where it was attached to the plant (stalk) and one where the style was. A seed has one scar, the hilum, where it was attached to the fruit wall. This is the simplest way to tell a fruit from a seed: a bean pod is a fruit, while each bean inside is a seed.
Why Dispersal Matters
Dispersal carries seeds away from the parent plant. This reduces competition for light, water and nutrients, helps plants colonise new areas, and lowers the chance that disease or pests wipe out all the young plants together.
Modes of Fruit and Seed Dispersal
| Agent | Adaptations | Examples |
|---|---|---|
| Animals | Fleshy, brightly coloured, sweet fruits eaten with seeds that pass through the gut; or hooks that stick to fur and clothes | Mango, guava, tomato; Blackjack (Bidens) seeds with hooks |
| Wind | Light, small seeds; hairs or wing-like extensions | Jacaranda (winged seeds); sodom apple and cotton (hairy seeds) |
| Water | Fibrous or spongy coats with air spaces so the fruit floats | Coconut |
| Self (explosive) | Pods dry unevenly and split open suddenly, throwing seeds out | Beans, peas, castor oil plant |
Activity
Collect five fruits or seeds from the school compound or home. For each, record its features (size, mass, hooks, wings, hairs, fleshiness) and predict its dispersal agent. Compare your predictions with classmates. Wash your hands afterwards, and do not taste unknown fruits; some, like castor seeds, are poisonous.
Original Practice Questions With Worked Answers
- What does the ovary become after fertilisation? The fruit.
- What does the ovule become? The seed.
- How can you tell a fruit from a seed? A fruit has two scars; a seed has one (the hilum).
- Name the dispersal agent for a seed with a wing. Wind.
- Give one reason why seed dispersal is important. It reduces competition between the young plants and the parent plant.
Cover the answers and attempt each question first. For timed practice, use the Grade 9 revision papers or the Grade 9 CBC Challenge. These notes are free; full revision access is available with the KSh 20 Day Pass or the KSh 500 Monthly Pass.
Frequently Asked Questions
What happens during fertilisation in flowering plants?
A pollen tube carries a male nucleus to the ovule, where it fuses with the egg cell to form a zygote.
What are the four agents of seed dispersal?
Animals, wind, water and the plant itself (explosive or self-dispersal).
Why are some fruits brightly coloured and sweet?
To attract animals that eat them and later drop the seeds away from the parent plant.
Is a bean pod a fruit or a seed?
The pod is a fruit because it develops from the ovary; the beans inside are seeds.