Pollination, Pollination, fertilisation and fertilisation and germination germination Life Cycle of a Flowering PlantLife Cycle of a Flowering Plant

Parts of a flowerParts of a flower

Lest we forgetLest we forget

There are sex cells inThere are sex cells in pollen grains (male cells)pollen grains (male cells) ovules (female cells)ovules (female cells)

Lest we forgetLest we forget

For fruits and seeds to form, male and For fruits and seeds to form, male and female sex cells must female sex cells must meetmeet and and fusefuse..

Since male and female sex cells are Since male and female sex cells are involved, this is called “involved, this is called “sexual sexual reproductionreproduction”.”.

Lesson objectivesLesson objectives

By the end of the lesson, pupils will be able By the end of the lesson, pupils will be able

toto learn about pollination and fertilisation.learn about pollination and fertilisation. list the agents of pollination.list the agents of pollination. learn about germination.learn about germination.

PollinationPollination

Definition:Definition:

The transfer of pollen grains from the The transfer of pollen grains from the anther to the stigma of a flower.anther to the stigma of a flower.

PollinationPollination

Two types of pollinationTwo types of pollination Self-pollinationSelf-pollination Cross-pollinationCross-pollination

PollinationPollination

Self-pollinationSelf-pollination

Transfer of pollen grains within one flower:Transfer of pollen grains within one flower: One flower.One flower. Pollen grains from the anther are Pollen grains from the anther are

transferred onto the stigma.transferred onto the stigma.

PollinationPollination

Cross-pollinationCross-pollination

Transfer of pollen grains from one flower to Transfer of pollen grains from one flower to

another:another: Two similar flowers.Two similar flowers. Pollen grains from the anther of one Pollen grains from the anther of one

flower are transferred onto the stigma of flower are transferred onto the stigma of the other flower.the other flower.

PollenPollen

Pollen of different plants have different Pollen of different plants have different shapes and sizes.shapes and sizes.

Pollen are small and light so that they Pollen are small and light so that they can be carried by the can be carried by the agents of agents of pollination.pollination.

PollenPollen

Agents of pollinationAgents of pollination

Plants generally do not transfer the Plants generally do not transfer the pollen from one flower to another by pollen from one flower to another by themselves.themselves.

Although a few plants do have self-Although a few plants do have self-pollination – pollen from flower’s anther pollination – pollen from flower’s anther pollinating its own stigma.pollinating its own stigma.

These plants need These plants need agents of agents of pollinationpollination to help them. to help them.

Agents of pollinationAgents of pollination

Insects (bees)Insects (bees) Other animals (birds and bats) Other animals (birds and bats) Wind Wind

Agents of pollinationAgents of pollinationInsects Insects pollen will stick to parts of insects’ bodies, e.g. pollen “bags” situated pollen will stick to parts of insects’ bodies, e.g. pollen “bags” situated

on the legs of bees.on the legs of bees.

Agents of pollinationAgents of pollinationOther animals (birds) Other animals (birds) these animals are usually nectar-drinking animals like sunbirds.these animals are usually nectar-drinking animals like sunbirds.

Agents of pollinationAgents of pollinationOther animals (bats) Other animals (bats) these animals are usually nectar-drinking animals like nectar-feeding these animals are usually nectar-drinking animals like nectar-feeding

bats.bats.

Agents of pollinationAgents of pollinationWind Wind pollen tend to be smaller and lighter in order to be carried by the pollen tend to be smaller and lighter in order to be carried by the

wind.wind.

FertilisationFertilisation

When the male sex cells fuse with the When the male sex cells fuse with the female sex cells within the ovule.female sex cells within the ovule.

The resulting embryo then develops The resulting embryo then develops into a seed.into a seed.

Unfertilised ovules cannot become Unfertilised ovules cannot become seeds.seeds.

Individual activityIndividual activity

Complete Complete Worksheet 18Worksheet 18 of of

Science Process Skills for Primary 5.Science Process Skills for Primary 5.

GerminationGermination

Definition:Definition:

The growth of the root through the seed The growth of the root through the seed

coat.coat.

GerminationGermination

When a seed lands on a place with When a seed lands on a place with sufficient sufficient warmth, waterwarmth, water andand airair, it starts to germinate., it starts to germinate.

Sunlight is not necessary for germination.Sunlight is not necessary for germination. First, the root of the baby plant grows out of the First, the root of the baby plant grows out of the

seed to form a seedling.seed to form a seedling. During this stage, the seedling cannot make its During this stage, the seedling cannot make its

own food.own food. It gets its energy from the food stored in its It gets its energy from the food stored in its

seed leaves.seed leaves.

GerminationGermination

Seed leaves are the parts of a seed that Seed leaves are the parts of a seed that protect the baby plant.protect the baby plant.

Next, the shoot appears and breaks through Next, the shoot appears and breaks through the soil and the first leaves unfold.the soil and the first leaves unfold.

The young plant is now able to make its own The young plant is now able to make its own food as the green leaves makes food in the food as the green leaves makes food in the sunlight (photosynthesis).sunlight (photosynthesis).

Note: seed leaves are the parts of a seed that Note: seed leaves are the parts of a seed that protect the baby plant, leaves are the part of protect the baby plant, leaves are the part of the plant that manufactures food. the plant that manufactures food.

Individual activityIndividual activity

Complete Complete Worksheet 19Worksheet 19 of Science of Science Process Skills for Primary 5.Process Skills for Primary 5.

Pupils to complete Pupils to complete Activity 14Activity 14 of of Activity Book.Activity Book.

SummarySummary

PollinationPollination - the transfer of pollen grains from the - the transfer of pollen grains from the anther to the stigma of a flower.anther to the stigma of a flower. Agents of pollinationAgents of pollination - animals that help plants transfer the - animals that help plants transfer the pollen from one flower to anotherpollen from one flower to another FertilisationFertilisation - when the male sex cells fuse with the female - when the male sex cells fuse with the female sex cells within the ovule.sex cells within the ovule. GerminationGermination - the growth of the root through the seed - the growth of the root through the seed coat.coat.

The endThe end