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प्रश्न
What is self-incompatibility?
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उत्तर
Sexual incompatibility occurs when a pistil with functioning female gametes fails to establish seeds after pollination with viable and fertile pollen capable of fertilizing another pistil. Sexual incompatibility can arise between members of different species or within the same species. The condition is also known as self-incompatibility.
APPEARS IN
संबंधित प्रश्न
List the different types of pollination depending upon the source of pollen gain.
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 ?
What are chasmogamous flowers?
What is meant by emasculation?
Add a note on pollination mechanism in Salvia.
Give the floral adaptations for anemophily.
Write two ways in which pollination may occur in plants.
Find the odd-one out, giving reason:
Ovary, style, pollen grain, stigma
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.
Put a tick mark (✓) against the correct alternative in the following statements
Vegetative propagation is not observed in:
Describe the Advantages and Disadvantages of self-pollination to the Plant.
The question has four options. Choose the correct answer:
Pollination by insect is known as
Very short answer type question:
What is hydrophily?
At which stage pollen grains are shed from the anther in Angiosperms?
Cleistogamous flowers are ______.
Anemophily type of pollination is found in ______.
Triple fusion in Capsella bursa pastoris is fusion of male gamete with ______.
The flower which does not open at all are called ______.
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 |
In which one of the following pollination is autogamous?
Correct definition of pollination is ______
Match the Column I with Column II.
| Column I | Column II |
| A. Pea | (i) Xenogamy |
| B. Jawar | (ii) Epihydrophily |
| C. Maize | (iii) Anemophily |
| D. Vallis | (iv) Bisexual |
| E. Cannabis | (v) Geitonogamy |
What is hypohydrophily?
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 | ______ |
Comparatively a large amount of pollen grains are wasted during ______.
Identify the set of correct statements:
- The flowers of Vallisneria are colourful and produce nectar.
- The flowers of waterlily are not pollinated by water.
- In most of water-pollinated species, the pollen grains are protected from wetting.
- Pollen grains of some hydrophytes are long and ribbon like.
- In some hydrophytes, the pollen grains are carried passively inside water.
Choose the correct answer from the options given below:
