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प्रश्न
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.
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उत्तर
1. Water Hydrophily
2. Insect Entomophily
3. Bat Chiropterophily
4. Birds Ornithophily
(Or)
1) Most of the Angiosperms produce bisexual flowers. Cross pollination is preferred by majority of flowering plants and they develop out breeding devices.
2) In many plants self pollination is avoided as stamens and carpels do not mature simultaneously. This
is called dichogamy.
3) In some plants, pollen grains are released much before stigma becomes receptive, this is protandry
e.g. Sunflower and in some plants, stigma becomes receptive first, this is protogyny e.g. Michelia.
4) The third device to avoid self pollination is genetic mechanism and it is called self-incompability or
self sterility, e.g. Orchids.
5) Pollen germination on the stigma of the same flower is inhibited. The fourth device is to produce
unisexual flowers. i.e. unisexuality.
6) In some plants like Castor, male and female flowers are produced on the same plant and such plants
are called monoecious. In dioecious plants like Papaya, male and female flowers are produced on
different plants. This condition prevents autogamy as well as geitonogamy while monoecious condition
prevents only autogamy.
APPEARS IN
संबंधित प्रश्न
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.
Add a note on pollination mechanism in Salvia.
Which one of the following is one of the characteristics of self-pollinated flowers?
Which of the following plant contain unisexual flower?
In which one of the following pollination is autogamous?
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?
Give any four floral adaptations for chiropterophily.
What are the major abiotic factors that influence habitat?
Name the following:
Aquatic plants which are anemophilous.
