Science Form 3

Chapter 4 : Reproduction4.9 Pollination

Group members : Nadia Binti Zulkifli(leader)Fatin Syahindah Binti Daud

Siti Mardiana Binti Mohd Saini Siva Letchumi a/p Tamil Selvan

Nur Hazirah Binti NordinNur Shafika Binti Aripin

Pollination

4.9 Pollination Pollination is the process of transferring ripe pollen

from the anther to stigma. There are two type of pollination : 1) Self-pollination – take place when the pollen

from the anther of a flower is transferred to the stigma of the same flower or another flower on the same plant.

Polen transferred to stigma of same flower

stigma

Pollen transferred to another flower of same plant

anther

stigma

anther

2) Cross-pollination- the transfer of pollen of a flower to the stigma of another flower on different plant of the same species.

anther

pollen

stigma

Table 4.9.1 Comparison between sel-pollination and cross pollination

Self-pollination Cross-pollination

Involves only one plant Involves two plants of the same species

Requires one or two flowers from the same plant

Requires two flowers from the different plant of the same species

If it involves one flower, both the anther and stigma must mature at the same time. If it involves two flowers, the anther and stigma can mature at different times

The anther and stigma can mature at different times

Less variety in new plants More variety in new plants

4.9.1 Pollinating agents Agents of pollination include organisms or media that transfer

the pollen grains from the anther to the stigma of a flower. Agents of pollination include humans and animals, wind and

water. The structure of flowers have certain characteristics to

promote pollination.1. Wind

Is a pollinating agent for most monocotyledonous plant, like maize, grass and paddy.

Wind-pollinated flowers usually : white or light in colour, small, have no smell and no

nectar. Have long filaments to expose the pollen to wind. Produce plenty of small, light and smooth pollen. The styles and stigma are long. The stigma is feathery

to trap the pollen carried by the wind.

1. Insects Attracted by big, colourful and scented flowers. When insect lands on the flower to suck nectar for food,

pollen sticks to the hairy legs and body of insect. When insect lands on another flower to collect food, the

pollen may drop off and stick on the stigma of that flower.

Insect-pollinated flowers : Produce small amounts of pollen. Such pollen is big, sticky, heavy and rough. Their style are short and the stigma has sticky surface.

2. Animals Pollinate flower when they suck nectar from the flowers. Such flowers are usually big, colourful, scented, and

produce rough and sticky pollen. The pollen sticks to the beak or body of the animals. When animals such a bird sucks out nectar with its long

and pointed beak, pollen sticks to the beak.

3. Watero Is a pollinating agent for water plants like Elodea

and Hydrilla. o The flower floats on water surface.o The water carries the pollen from the pollen from the

anther to the stigma.

Elodea Hydrilla

Table 4.9.2 Comparison between wind and insect pollinated flowers

Wind-pollinated flower Insect-pollination flower

Small, pale coloured, not scented, no nectar

Big, brightly coloured, scented, nectar present

Long filament with big anther at the end, filament sways in the wind and pollen disperses

Short filament and small anther at the end

Plenty of small, light and smooth pollen

Big, rough, sticky and less amount of pollen

Long style Short style

Long and feathery stigma Short and sticky stigma

The Advantage Of Cross-pollination

New varities of plants Healthier plants which can adapt better to changes in

invironment Healthier seeds New plants that are more resistant to pest and

diseases

Use Of Cross-pollination In Agriculture

Human act as pollinating agent; widely used in the field of agriculture to produce better and higher quality crops.

In Malysia, the various agricultural agencies like the Malayan Agriculture Research and Development Institute (MARDI) and the alaysian Palm Oil Bord (MPOB) are responsible for carrying out research to increase the quantity and qualiti of agricultural products.

Among the new crop plants produce by cross-pollination are oil palm, maize plants and papaya plants.

Thank You!