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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Assertion : Mammalian ova produces hyaluronidase.

Reason : The eggs of mammal are microlecithal and telolecithal.

  • 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 : The primitive atmosphere was reducing one i.e. without oxygen.

Reason : In the primitive atmosphere, oxygen was involved in forming ozone layer.

  • 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 : 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


Assertion : A gamete may carry either of the traits but not both.

Reason : This is Mendel's second law or law of independent assortment.

  • 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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Assertion : Amniocentesis is a process of foetal sex determination.

Reason : Metabolic errors and other diseases can be diagnosed prenatally by this process.

  • 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 : Bursa fabricii lies on the ventral side of the cloaca in birds.

Reason : Bursa fabricii is related with flight adaptation.

  • 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 : 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 : Jave Apeman, Peking man and Heidelberg man are the fossils of Homo erectus.

Reason : Homo erectus evolved from Homo habilis.

  • 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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Assertion : Restriction enzymes cut the strand of DNA to produce sticky ends.

Reason : Stickiness of the ends facilitates the action of the enzyme DNA polymerase.

  • 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