Multiple Choice Questions

Advertisement

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.


A.

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

The ratio of cytokinin (kinetin) to auxin (IAA) is important in determining the nature of organogenesis in tissue culture. High level of kinetin results in bud initiation, while high concentration of auxin favours rooting.


Advertisement

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

  • differentiation

  • re-differentiation

  • de-differentiation

  • re-juvenation


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: 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.


Advertisement

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


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

  • Bt genes

  • RNAi genes

  • Cry genes

  • Endogeneous cytoplasmic defence genes


DNA and RNA comprise of

  • sugar, phosphate, base

  • sugar, phosphate

  • base, phosphate

  • sugar, base


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.


Advertisement
<

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.


Advertisement