Page 146 - Knowledge Organiser Yr7 24-25

7. Pollination
State five features common to insect-pollinated flowers
1. Brightly coloured and sweet-smelling petals
2. Small amounts of pollen production 3. Sticky or spiky pollen
4. Sticky stigma
5. Nectar-secreting cells
What is nectar?
A sugar-rich liquid which insects use as food
State four features common to wind-pollinate flowers
1. Small petals, often brown or dull green 2. Large amounts of pollen production
3. Pollen which has a low mass
4. No nectar-secreting cells
How does insect pollination occur?
1. An insect visits a flower and pollen sticks to it
2. The insect moves to the flower of another plant (or same plant)
3. The pollen rubs off on to the stigma
How does wind pollination occur?
The pollen from the flower of one plant is blown by the wind and lands on the stigma of another plant’s flower
9. Seeds and Fruits
7.5 9.1
What happens to the ovary of a flower following fertilisation?
9.2 What is a fruit? 9.3
9.4
9.5
A developed ovary containing seeds
It develops into a fruit
What are the three main structures found in a seed?
A seed coat, an embryo, a food store
What is function of each structure fond in the seed?
• Seed coat – for protection
• Embryo – to contain the young root and shoot
• Food store – for the young plant to use
• before it can photosynthesise
What are the names of the structures labelled in this diagram?
7.6 7.7
7.8
7.9
8.1 8.2
9.6 What is germination? 9.7
When a seed starts to grow
Name three factors required for germination
Water, oxygen, warmth
8. Fertilisation in Flowering Plants
What occurs for fertilisation to take place in flowering plants?
The nucleus of a pollen joins with the nucleus of an egg to make a seed
What are the main steps involved in fertilisation?
1. A pollen grain is transferred to the stigma 2. A pollen tube grows from the stigma to the
ovary through the style
3. The nucleus of the pollen grain passes
through the pollen tube
4. It then joins with the egg cell inside an
ovule of the ovary
5. The fertilised egg will develop into a seed
10. Seed Dispersal
10.1
What is seed dispersal?
The movement of seeds away from the parent plant
10.2
What is the purpose of seed dispersal?
To allow a seed to germinate away from other plants to reduce competition for water and sunlight
10.3
What are the four main methods of seed dispersal?
Wind, animal, water, explosive
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Knowledge Base: Science 7.11 Reproduction Year 7