Multiple Choice Questions

Advertisement

Vernalisation is subjected to plants growing in

  • tropical areas

  • sub tropical areas

  • temperate areas

  • hot areas/arctic region.


C.

temperate areas

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually flower.

Many temperate plants have vernalisation requirement and must experience a period of low temperature in winter, to initiate or accelerate flowering process, or in many fruit tree species, to induce dormancy and then break dormancy prior to flowering.


Advertisement

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

  • Bt genes

  • RNAi genes

  • Cry genes

  • Endogeneous cytoplasmic defence genes


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.


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.


DNA and RNA comprise of

  • sugar, phosphate, base

  • sugar, phosphate

  • base, phosphate

  • sugar, base


Advertisement

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.


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.


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.


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


Advertisement
<

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

  • differentiation

  • re-differentiation

  • de-differentiation

  • re-juvenation


Advertisement