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प्रश्न
Describe the structure of its microsporangium.
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उत्तर
A microsporangium is a cylindrical sac which appears circular in the transverse section. It contains the following parts:
(1) Outer wall
(2) Central homogeneous sporogenous tissue
(3) Epidermis
(4) Endothecium
(5) 1–3 middle layers and tapetum
The outer three layers perform the function of protection in the younger anther andthe mechanism of dehiscence in the ripe anther.The endothecial cells develop fibrous thickening of α-cellulose on the inner and radial walls and die. The innermost layer is called the tapetum. It nourishes the developing pollen grain.
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संबंधित प्रश्न
Fill in the blanks with suitable words.
Different timings for the maturation of gynoecium and androecium is called ________.
Give one word/term for the following:
When stigma and anthers do not grow up to the same height, which favors only cross-pollination.
Give one word/term for the following:
Pollination of flowers by insects.
Describe the advantages and disadvantages of cross-pollination to the plant.
Differentiate between geitonogamy and xenogamy (allogamy).
From among the situations given below, choose the one that prevents both autogamy and geitonogamy.
Mention any one example of the anemophilous flower.
Give any four floral adaptations for chiropterophily.
Briefly discuss any two methods by which plants avoid self-pollination.
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:
