51.

Assertion : Interferons are a type of antibodies produced by body cells infected by bacteria.

Reason : Interferons stimulate inflammation at the site of injury.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Organ transplantation patients are given immunosuppressive drugs.

Reason : Transplanted tissue has antigens which stimulate the specific immune response of the recipient.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : In humans, the gamete contributed by the male determines whether the child produced will be male or female.

Reason : Sex in humans is a polygenic trait depending upon a cumulative effect of some genes on X chromosome and some on Y-chromosome.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Replication and transcription occur in the nucleus but translation occurs in the cytoplasm.

Reason : mRNA is transferred from the nucleus into the cytoplasm where ribosomes and amino acids are available for protein synthesis.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Human ancestors never used their tails and so the tail expressing gene has disappeared in them.

Reason : Lamarck's theory of evolution is popularly called theory continuity of germ plasm.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Presently, the global atmosphere is warming up.

Reason : The depletion of stratospheric ozone layer has resulted in increase in ultraviolet radiations reaching the earth.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false.

• If both Assertion and Reason are false

Assertion : Comparative biochemistry provides a strong evidence in favour of common ancestry of living beings.

Reason : Genetic code is universal

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Darwin's finches show a variety of beaks suited for eating large seeds, flying insects and cactus seeds.

Reason : Ancestral seed-eating stock of Darwin's finches radiated out from South American mainland to different geographical areas of the Galapagos Islands, where they found competitorfree new habitats.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false.

Assertion : The age-sex structure of human population in countries like France and Germany gives a steep pyramid.

Reason : In countries like Sudan and India the population is increasing at a rapid rate.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false

• If both Assertion and Reason are false

Assertion : Agrobacterium tumefaciens is popular in genetic engineering because this bacterium is associated with the roots of all cereal and pulse crops.

Reason : A gene incorporated in the bacterial chromosomal genome gets automatically transferred to the crop with which the bacterium is associated.

• If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion

• If both Assertion and Reason are true but the Reason is not the correct explanation of the assertion

• If Assertion is true but Reason is false.

• If both Assertion and Reason are false.