Advertisements
Advertisements
प्रश्न
When and why does a plant breeder employ the emasculation technique?
Advertisements
उत्तर
Plant breeders employed this technique to prevent pollination within the same flower or to pollinate stigmas with pollen of the desired variety. To remove the anthers, the flowers are covered with a bag before they open. This ensures that the flower is pollinated by pollen grains obtained from desirable varieties only. Later, the mature, viable, and stored pollen grains are dusted on the bagged stigma by breeders to allow artificial pollination to take place and obtain the desired plant variety.
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 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?
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 ?
Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.
What is meant by pollination?
Mention any two contrivances in flowers which favour cross-pollination.
Can a plant flowering in Mumbai be pollinated by pollen grains of the same species growing in New Delhi? Provide explanations to your answer.
- Nucellus
- Antipodals
- Synergids
- Micropyle
Put a tick mark (✓) against the correct alternative in the following statements
Vegetative propagation is not observed in:
Explain water pollination in detail with its types.
Give an account of any two biotic agents for pollination along with their adaptations.
Choose the correct statement from the following.
From among the situations given below, choose the one that prevents both autogamy and geitonogamy.
Cleistogamous flowers are ______.
A dioecious flowering plant prevents both ______.
Which of the following pair has haploid structures?
Feathery stigma occurs in ______.
Triple fusion in Capsella bursa pastoris is fusion of male gamete with ______.
Heterostyly as a contrivance for cross-pollination is found in ______.
The flower which possesses both androecium and gynoecium is called perfect or ______.
During Hybridization process anther of the bisexual flower is removed before it dehisces is 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 |
Which type of pollination does the figure indicate?
Consider the following statements depicting adaptation of flowers to carryout successful pollination.
- Stigma is long, sticky and unwettable.
- Sepals, petals or perianth (if present) have waxy coating.
- Stamens with long filament and versatile anthers.
- Tubular corolla is seen.
- Flowers are noctumal.
Which of the above statements clearly depict hydrophily?
Mention any one example of the anemophilous flower.
What is epihydrophily?
What are the major abiotic factors that influence habitat?
