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प्रश्न
Enlist advantages and disadvantages of cross pollination
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उत्तर
Advantages of cross pollination:
i. Offsprings produced are healthier and are well adapted to the environment.
ii. Seeds are produced in large numbers with higher viability and of better quality.
iii. Possibility of variations results in new desired varieties of plants, hence favours the process
of evolution.
iv. The offsprings show better vigour (hybrid vigour) and vitality.
Disadvantages of cross pollination:
i. The plants have to depend upon various external agencies.
ii. There is expenditure of energy due to the adaptations such as bright colour, nectar, fragrance,
etc. in attracting insects.
iii. There is considerable wastage of pollen grains.
iv. Since cross pollination result in the formation of new genotypes, it may also develop
undesirable characters in the progeny. Some desirable characters may get eliminated.
v. Genetic purity is not maintained.
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संबंधित प्रश्न
What is meant by emasculation?
Name two characteristics of flowers in which pollination occur by wind.
What is meant by pollination?
Fill in the blanks:
The two kinds of pollination are __________ and __________.
Complete the following chart and rewrite.
| Sr.No. | Agencies | type of pollination |
| 1 | Water | .................... |
| 2 | ........................... | Entomophily |
| 3 | Bat | .................... |
| 4 | ....................... | Ornithophily |
(Or)
Explain outbreeding devices in angiospermic plants.
In bisexual flowers, maturation of gynoecium before androecium is known as ______.
Coelacanth was caught in South Africa. State the significance of the discovery of Coelacanth in the evolutionary history of vertebrates.
Very short answer type question:
What is hydrophily?
Insect pollinated flowers are ______.
In the dioecious aquatic plant shown, identify the characteristics of the male flowers that reach the female flowers for pollination:
| Size of the flower | Colour of flower | The characteristic feature of pollen grain | |
| A | small | brightly coloured | Lightweight and non-sticky |
| B | large | colourless | large and sticky |
| C | small | white | small, covered with mucilage |
| D | large | colourless | non-sticky |
