81.

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.

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

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: 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.

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.

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.

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

• differentiation

• re-differentiation

• de-differentiation

• re-juvenation

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