Advertisements
Advertisements
प्रश्न
Give an account of various abiotic agencies used in pollination along with their adaptations for pollination.
उत्तर
Abiotic agencies for pollination include wind and water.
i. Pollination by wind:
- Anemophily:
Pollination carried out by wind is called as anemophily. Important crop plants like wheat, rice, corn, rye, barley, oats, and other plants like palms are wind-pollinated. - Adaptations in anemophilous flowers:
- The flowers are small, inconspicuous, colourless, without nectar and fragrance (odour).
- The pollen grains are light in weight, dry and produced in large numbers to increase chances of pollination considering wastage of pollen grains.
- Stigma is feathery to trap pollens carried by wind currents.
- Stamens are exserted with long filaments and versatile anthers.
- Stamens and stigmas are exposed to air currents.
ii. Pollination by water
- Hydrophily: Pollination carried out by the water is called hydrophily.
- Adaptations in hydrophilous flowers:
- Flowers are small and inconspicuous.
- Perianth and other floral parts are unwettable.
- Pollen grains are long and unwettable due to the presence of mucilage.
- Nectar and fragrance are lacking in flowers.
c. It is found in some 30 genera of aquatic monocots. E.g. Vallisneria, Zostera, Ceratophyllum etc.
APPEARS IN
संबंधित प्रश्न
Geitonogamous flowering plants are genetically autogamous but functionally cross-pollinated. Justify.
A flower of tomato plant following the process of sexual reproduction produces 200 viable seeds.
Answer the following questions giving reasons :
(a) What would have been the minimum number of ovules present in pre-pollinated pistil ?
(b) How many microscope mother cells would minimally be required to produce requisite number of pollen grains ?
(c) How many pollen grains must have minimally pollinated the carple ?
(d) How many male gametes would have used to produce these 200 viable seeds ?
(e) How many megaspore mother cells were required in this process ?
Describe the structure of its microsporangium.
Select and write the most appropriate answer from the given alternatives for the following subquestion:
A versatile anther is an adaptation for _______ type of pollination.
Name of the parts of the ovary which give rise to:
Fruit wall ______
For which of the following attractants and rewards are required?
Triple fusion in Capsella bursa pastoris is fusion of male gamete with ______.
Which of the following floral adapation are adapted by hydrophilous flowers?
Describe any three adaptations in hydrophilous flowers.
When and why does a plant breeder employ the emasculation technique?