Assertion: Hb^s Hb^s denotes the homozygous condition for sickle-cell anaemia.

Reason: It occurs due to substitution of glutamic acid by valine at the 6 position of (B-chain of Hb.

• 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.

RNA interference is essential for the

• cell proliferation

• cell defence

• cell differentiation

• micropropagation

Assertion: There are 34 biodiversity hotspots in the world.

Reason: High level of species richness is a criteria for selection of a biodiversity hotspot.

• 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: Inbreeding increases homozygosity, thus exposes harmful recessive genes, which are eliminated by selection.

Reason: Continued inbreeding reduces fertility and productivity.

• 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: Some marine animals find it difficult to live in fresh water and vice versa.

Reason: Some animals can tolerate a narrow salinity range, while others can tolerate a wide salinity range.

• 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: In a terrestrial ecosystem, detritus food chain is the major conduit for energy flow.

Reason: Solar energy is the direct source for energy supply in a detritus food chain.

• 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: Filarial worm is transmitted to humans by Culex mosquito.

Reason: Culex prefers to breed in fresh water.

• 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: AIDS is caused by the HIV, a retro-virus.

Reason: Retroviruses have RNA genome.

• 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 male is found to be lacking facial hair and pubic hair.

Reason: It is a case of hyposecretion of testosterone from Leydig's cells of testes.

• 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: Extra oxygen consumption in human, body is known as oxygen debt.

Reason: The extra oxygen is required by the body to oxidise the accumulated lactic acid produced during strenuous exercise.

• 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.