Multiple Choice Questions

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Assertion : Pollen mother cells (PMCs) are the first male gametophytic cells.

Reason : Each PMC gives rise to two pollens.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


D.

If both assertion and reason are false

Primary sporogenous cell gives rise to microspore mother cells or pollen mother cells (PMCs). They are sporophytic in nature i.e., diploid. These cells undergo meiosis (reduction division) which gives rise to 4 microspores or pollens and this formation of microspores or pollens is called microsporogenesis. Microspores represent the beginning of the gametophytic phase and they are haploid in nature.


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Upon fertilization, what structure develops from carpel?

  • Testa

  • Tegmen

  • Pericarp

  • Perisperm


Assertion: In some species of asteraceae and poaceae seeds are formed without fertilization.

Reason: Formation of fruit without fertilization is called parthenocarpy.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


Even after killing the generative cell with a laser beam, the pollen grain of a flowering plant germinates and produces normal pollen tube because

  • laser beam stimulates pollen germination and pollen tube growth

  • the laser beam does not damage the region from which pollen tube emerges

  • the contents of killed generative cell permits germination and pollen tube growth

  • the vegetative cell has not been damaged


Assertion : Protandry and protogyny ensures cross fertilization.

Reason : Cross fertilization introduces variation in progeny.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false


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Which one of the following pairs of plant structures has haploid number of chromosomes

  • Nucellus and antipodal cells

  • Egg nucleus and secondary nucleus

  • Megaspore mother cell and antipodal cells

  • Egg cell and antipodal cells


Assertion : Emasculation prevents self- pollination in flowers.

Reason : Emasculation is the removal of anthers from a bisexual flower.

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


Assertion: Maize is an albuminous seed. 

Reason: Endosperm is completely absorbed by its growing embryo

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


Apomixis is

  • formation of seeds by fusion of gametes

  • formation of seeds without syngamy and meiosis

  • formation of seeds with syngamy but no meiosis

  • none of the above


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Assertion: Nuclear endosperm is formed by subsequent nuclear division without wall formation.

Reason: Coconut is an example of such endosperm, where the endosperm remains nuclear throughout the development of the fruit

  • If both assertion and reason are true and reason is the correct explanation of assertion

  • If both assertion and reason are true but reason is not the correct explanation of assertion

  • If assertion is true but reason is false

  • If both assertion and reason are false.


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