MCQ
Self-incompatibility is a device for

$I$. Ensuring cross-pollination

$II$. Preventing self-pollination

$III$. Ensuring self-fertilisation

$IV$. Genetic control for self-fertilisation

Choose the correct statements from those given above

  • A
    $I, II \;and \;III$
  • $I, II \;and \;IV$
  • C
    $I, III \;and\; IV$
  • D
    $I, II, III \;and\; IV$

Answer

Correct option: B.
$I, II \;and \;IV$
b
$I, II, III \;and \;IV$ are correct Flowering plants have developed many devices to discourage self-pollination. In some species, pollen, releases and stigma receptibility is non-syncronised, ie, either the pollen is released before the stigma becomes receptive or stigma becomes receptive much before the release of pollen.In some other species the anther and stigma are placed at the different positions so that the pollen can not come in contact with the stigma of same flower: Both these devices prevent autogamy.

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Mark the given statements True (T) or False (F).
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(x) Sclerenchyma consists of long, narrow cells with thin and lignified cell walls having a few or numerous pits.
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