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Sexual Reproduction in flowering Plants

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Biology

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Biology

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CBSE Gujarat Board Haryana Board

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Class 10 Class 12

Importance of day length in flowering of plants was first shown in 

  • Lemna

  • tobacco

  • Cotton 

  • Petunia


B.

tobacco

The phenomenon of photoperiodism was first discovered by Garner and Allard (1920, a mammoth variety of tobacco could be made to flower only by reducing the light hours with artificial darkening. On the basis of photoperiodic response to flowering, plants (tobacco), long day plant (eg, wheat, hanbane), short - long day plant (eg Campanula), long short day plants, (eg, wild kidney bean) and day neutral plants (eg, cotton).

The phenomenon of photoperiodism was first discovered by Garner and Allard (1920, a mammoth variety of tobacco could be made to flower only by reducing the light hours with artificial darkening. On the basis of photoperiodic response to flowering, plants (tobacco), long day plant (eg, wheat, hanbane), short - long day plant (eg Campanula), long short day plants, (eg, wild kidney bean) and day neutral plants (eg, cotton).


Simultaneous meiotic division of microspore mother cells leads to :
  • tetrahedral tetrad
  • linear tetrad
  •  isobilateral
  • decussate tetrad.

A.

tetrahedral tetrad

In a bisexual flower when the gynaecium matures earlier than anther, it is called as :
  • protandry
  • protogyny
  • herkogyny
  • None of the above.

B.

protogyny

The innermost layer of anther is tapetum whose function is :
  • dehiscence
  • mechanical
  • nutrition
  •  protection.

C.

nutrition

The female gametophyte of a typical dicot at the time of fertilization is:
  •  8-celled
  • 7-celled
  • 6-celled
  • 4-celled

B.

7-celled

The fertilization occurs in the :
  • ovary
  • ovule
  • embryo sac
  • nucellus.

A.

ovary