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Multiple Choice Questions

Assertion: Plant growth regulators (PGRs) are very important for plant growth and development.

Reason: Auxins do not induce flowering in gymnosperms

  • 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.


Which of the following genes do not occur naturally in living organisms

  • Bt genes

  • RNAi genes

  • Cry genes

  • Endogeneous cytoplasmic defence genes


Gibberellins can promote seed germination because of their influence on

  • rate of cell division

  • production of hydrolysing enzymes

  • synthesis of abscisic acid

  • absorption of water through hard seed coat.


Assertion: Yeasts are unicellular fungi that are used in bakery and brewery industries.

Reason: Potato spindle tuber disease is caused by viroids

  • 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: No secondary growth takes place in monocots.

Reason: Secondary growth is not related with cambium.

  • 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.


Vernalisation is subjected to plants growing in

  • tropical areas

  • sub tropical areas

  • temperate areas

  • hot areas/arctic region.


Assertion: A correct concentration of auxin and cytokinin is required for the development of root and shoot in a callus.

Reason: When the ratio of kinetin to auxin is high, then only shoots develop. But when the ratio is low then only roots develop.

  • 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.


The phenomenon that operates in the formation of root or shoot in a callus culture is

  • differentiation

  • re-differentiation

  • de-differentiation

  • re-juvenation


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One hormone hastens maturity period in juvenile conifers, a second hormone controls xylem differentiation, while the third hormone increases the tolerance of plants to various stresses. They are respectively

  • Gibberellin, Auxin, Ethylene

  • Auxin, Gibberellin, Cytokinin

  • Gibberellin, Auxin, ABA

  • Auxin, Gibberellin, ABA


DNA and RNA comprise of

  • sugar, phosphate, base

  • sugar, phosphate

  • base, phosphate

  • sugar, base


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