Advertisements
Advertisements
प्रश्न
Make a list of any three outbreeding devices that flowering plants have developed and explain how they help to encourage cross-pollination.
List any three outbreeding devices that flowering plants have developed for cross-pollination and explain how they help to encourage cross-pollination.
Advertisements
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
Lever mechanism of pollination is observed in
- Salvia
- Jasmine
- Bougainvillea
- Butea
Explain the post-pollination events leading to seed production in angiosperms.
Why angiosperm anthers are called dithecous?
What is self-incompatibility?
Fill in the blank:
Male sex cells in plants are called _________.
Can a unisexual flower be self pollinated?
Select and write the most appropriate answer from the given alternatives for the following subquestion:
A versatile anther is an adaptation for _______ type of pollination.
Name of the parts of the ovary which give rise to:
Fruit wall ______
Give one word/term for the following:
Pollination of flowers by insects.
In bisexual flowers, maturation of gynoecium before androecium is known as ______.
Differentiate Between Cross Pollination and Self Pollination:
Mention various adaptations for wind pollination.
Give an account of any two biotic agents for pollination along with their adaptations.
Even in absence of pollinating agents seed-setting is assured in ______.
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 one of the following may require pollinators, but is genetically similar to autogamy?
Correct definition of pollination is ______
Describe any three adaptations in hydrophilous flowers.
Briefly discuss any two methods by which plants avoid self-pollination.
