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प्रश्न
Explain water pollination in detail with its types.
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उत्तर
Definition:
Pollination carried out by water is called hydrophily.
Two types of hydrophily:
i. Hypohydrophily:
- In this pollination occurs below the surface of the water.
- Here the pollen grains are heavier than water, thus they sink down and caught by stigmas of female flowers.
- For e.g. In Zostera (sea grass) the pollen grains are long, ribbon-like, and without exine.
ii. Epihydrophily:
- In this pollination occurs on the surface of the water.
- The pollen grains float on the water surface and reach the stigma of the female flower.
- Vallisneria is a submerged dioecious, fresh water aquatic plant. In this, female flowers reach the water surface temporarily to ensure pollination and male flowers float on the surface of the water.
- The specific gravity of these pollen grains is equal to that of water. Due to which they float on the surface of the water.
- Due to water currents, pollen grains are carried to stigma and pollination occurs.
संबंधित प्रश्न
A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds.
Answer the following questions giving reasons :
(a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil?
(b) What would have been the minimum number of ovules present in the ovary?
(c) How many megaspore mother cells were involved?
(d) What is the minimum number of microspore mother cells involved in the above case?
(e) How many male gametes were involved in this case?
What is meant by emasculation?
Name of the part of the ovary which gives rise to:
Fruit ______
When maturation time of reproductive parts in a flower is different.
Give one word/term for the following:
Pollination of flowers by birds.
Mention any two contrivances in flowers which favour cross-pollination.
Type of interaction where an individual sacrifices its own welfare (life) for the benefit of another animal of its own species is ______.
Put a tick mark (✓) against the correct alternative in the following statements
Pollen is produced in the
Write different modes of pollination in detail with suitable examples.
Autogamy can occur in a chasmogamous flower if ______.
