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प्रश्न
Can cross-pollination occur in cleistogamous flowers? Give reason for your answer.
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उत्तर
Cross-pollination cannot occur in cleistogamous flowers. Cleistogamous flowers do not open at all. In these flowers, the anthers and stigma are close together; when the anthers dehisce in the flower buds, pollen grains touch the stigma, resulting in pollination. As a result, these flowers are always self-pollinated since they remain closed, and cross pollen cannot land on the stigma. Cleistogamous flowers can pollinate and set seeds without pollinators.
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संबंधित प्रश्न
With the help of a suitable example, explain protandry.
As a senior biology student you have been asked to demonstrate to the students of secondary level in your school, the procedure(s) that shall ensure cross-pollination in a hermaphrodite flower. List the different steps that you would suggest and provide reasons for each one of them.
Explain the post-pollination events leading to seed production in angiosperms.
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 ?
Name the part of the flower which the tassels of the corn- cob represent.
Mention two strategies that evolved to prevent self-pollination in flowers.
Give the floral adaptations for anemophily.
Mention any two contrivances in flowers which favour cross-pollination.
Put a tick mark (✓) against the correct alternative in the following statements
Vegetative propagation is not observed in:
Name the two types of pollination.
Describe pollination. How many types of pollinations are found?
Write different modes of pollination in detail with suitable examples.
At which stage pollen grains are shed from the anther in Angiosperms?
What are the different adaptations shown by bird-pollinated flowers?
Explain water pollination in detail with its types.
Give an account of any two biotic agents for pollination along with their adaptations.
Give an account of various abiotic agencies used in pollination along with their adaptations for pollination.
Cleistogamous flowers are ______.
Pollination by water occurs in ______.
A dioecious flowering plant prevents both ______.
Feathery stigma occurs in ______.
Which of the following is not a water pollinated plant?
Insect pollinated flowers are ______.
In which one of the following pollination is autogamous?
Pollination in water lilies is carried out by ______.
What is hypohydrophily?
Name the following:
Aquatic plants which are anemophilous.
Complete the following table:
| Sr. | Type of pollination | Agent | Kind of flower | Examples |
| (i) | ______ | Wind | ______ | Maize |
| (ii) | Chiropterophily | ______ | Dull colour, with strong fragrance, abundant nectar | Adansonia |
| (iii) | Entamophily | Insects | ______ | Rose/Jasmine |
| (iv) | Ornithophily | ______ | Brightly coloured, large and showy. They secrete profuse, dilute n ectar | ______ |
Briefly discuss any two methods by which plants avoid self-pollination.
