Question

What are the advantages and disadvantaged of self pollination nad cross pollination?

Answer 1

*pollination is the process of transfer of pollen grains from anther and their deposition on he stigma of the flower. Pollination can be self-pollination or cross pollination.
*Self-pollination is the transfer of pollen grains from anther to the stigma of the same flower whereas cross pollination is the deposition of pollen grains from anther of one flower to stigma of another flower of another plant.
* Self-pollination occurs  even in closed flower whereas cross pollination occurs when the flowers are open.
* Self-pollination does not require external agent whereas cross pollination requires external agent.
* Self-pollination preserves useful characters whereas cross pollination is unable to preserve highly useful characters.
* Self-pollination does not help in producing new varieties and species whereas cross pollination is the mechanism  which aids in producing new varieties and species.
* Self-pollination produces pure lines whereas cross pollination gives rise to variations in offspring.
 
 

Answer 2

hi

here's your answer

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Advantages of cross pollination:-

◆Progeny shows enhanced vigor.
◆Offsprings are more viable and resistant.
◆There is a possibility to get new desirable characters.
◆Yield of crop can be maintained.
◆It helps in evolution.
◆Undesirable characters of the plant can be eliminated.

Disadvantages of cross pollination:-

◆Pollination may fail due to distance barrier.
◆ Flowers have to totally depend on the external agencies for pollination.
◆ More wastage of pollen.
◆It may introduce some undesirable characters.

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Advantages of self- pollination:-

◆In self- pollination, there is no diversity in the genes and therefore the purity of the race is maintained.

◆ The plants do not depend on external factors for pollination and even smaller quantities of pollen grains produce have a good success rate in getting pollinated.

◆ Self- pollination ensures that recessive characters are eliminated.

Disadvantages of self- pollination:-

◆there is no mixing up of genes, there are no new characters or features that are introduced into the lineage of the offsprings.

◆Self- pollination is said to reduce the vigor and vitality of the race as there are no new features introduced.

◆Without new characters introduced, the resultant offspring's immunity to diseases reduces.

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