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प्रश्न
Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.
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उत्तर
- Dichogamy: Flowers are unisexual, so self-pollination is not possible. The plants may be monoecious, bearing both male and female flowers (e.g. maize), or dioecious, bearing male and female flowers on separate plants (e.g. mulberry, papaya).
- Prepotency: Pollen grains of another flower germinate more rapidly on the stigma than pollen grains of the same flower. Examples of this include apples and grapes.
- Self-sterility (Self-incompatibility): Pollen grains of a flower do not germinate on the stigma of the same flower because of the presence of similar self-sterile genes. Examples of this include tobacco, potatoes, and crucifers.
APPEARS IN
संबंधित प्रश्न
Fill in the blanks with suitable words.
_______ is a water-pollinated flower.
Give one word/term for the following:
When stigma and anthers do not grow up to the same height, which favors only cross-pollination.
Describe the advantages and disadvantages of cross-pollination to the plant.
Type of interaction where an individual sacrifices its own welfare (life) for the benefit of another animal of its own species is ______.
Give four adaptations shown by flowers pollinated by wind.
Answer the following question.
Write the difference in the characteristics of the progeny produced as a result of the two processes.
Put a tick mark (✓) against the correct alternative in the following statements
Pollen is produced in the
Give an account of various abiotic agencies used in pollination along with their adaptations for pollination.
Wind pollination is common in ______.
A particular species of plant produces light, non-sticky pollen in large numbers and its stigmas are long and feathery. These modifications facilitate pollination by ______.
Cleistogamous flowers are ______.
Flowers which have single ovule in the ovary and are packed into inflorescence are usually pollinated by ______.
Chief pollinators of agricultural crops are ______.
Heterostyly as a contrivance for cross-pollination is found in ______.
Which one of these statements is incorrect?
The following statements seem to describe the water-pollinated submerged plants.
A botanist studying Viola (common pansy) noticed that one of the two flower types withered and developed no further due to some unfavorable condition, but the other flower type on the same plant survived and it resulted in an assured seed set. Which of the following will be correct?
In which one of the following pollination is autogamous?
What is self-incompatibility?
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?
Name the following:
One plant each of Hypohydrophily and epihydrophily.
