Question

Differentiate between self pollination and cross pollination.

Answer 1

Pollination is the process by which pollen grains from the anther are transferred to the stigma. Anther and stigma and male and female reproductive organs of a flower.

Complete answer:
Flowers are fertilised when the pollen grains are transferred from the anther to the stigma and this process is known as pollination .The pollen grain fuses with the egg in the stigma and this process is known as fertilization. Fertilization cannot take place until and unless pollination occurs.
There are two types of pollination,
->Cross pollination
->Self pollination

Self pollination	Cross pollination
The process can occur in the same flower	The process occurs in two different flowers
It transfers pollen grains from the anther to stigma within the same flower	It is the transfer of pollen grains from anther of one flower to stigma of another flower
It can cause homogeneous conditions	It can cause heterozygous conditions
It can cause inbreeding	It can cause outbreeding
The flowers produce limited amounts of pollen grains	The flowers produce very high amounts of pollen grains
It reduces gene pool	It maintains the gene pool
There is no need of pollinators for transfer of pollen grains	There is a need for pollinators - animals, wind, etc
It requires only one parent plant	It requires two parent plants
The process can be carried out when the flowers are closed	The process can only be carried out when the flowers are open
It can increase genetic uniformity	It decreases genetic uniformity
Example: Arabidopsis thaliana	Example: Apples, daffodils

Note: The different types of cross pollination are,

Zoophily - In this animals help in the process of pollination
Anemophily - In this wind is involved the process of pollination
Anthropophily - This is an artificial mode of pollination