An example of gene therapy is

• production of injectable hepatitis B vaccine

• production of vaccines in food crops like potatoes which can be eaten

• introduction of gene for adenosine deaminase in persons suffering from Severe Combined Immuno Deficiency (SCID)

• production of test tube babies by artificial insemination and implantation of fertilised eggs

Apomixis is

• formation of seeds by fusion of gametes

• formation of seeds without syngamy and meiosis

• formation of seeds with syngamy but no meiosis

• none of the above

53.

A small rise in the body temperature of humans is corrected by

(i) sweating
(ii) dilating the skin arteries
(iii) constricting the skin arteries
(iv) increased tension of muscles in the skin

• (i) only

• (ii) only

• (i) and (ii)

• (iii) and (iv)

Assertion: Darwin's finches are a classical example of natural selection.

Reason: Darwin explained that the difference in size and shape of the beaks of the species was a result ofthe adaptation ofthe species to different food habits.

• 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: BOD of a river polluted by sewage is more than 20 ppm.

Reason: Polluted river contains excess of organic matter.

• 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: GM foods are facing widespread resistance by the people.

Reason: GM foods have mutated genes which cause infections and allergies.

• 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 recombinant DNA technology, human genes are often transferred into bacteria (prokaryotes) or yeasts (eukaryotes).

Reason: Both bacteria and yeasts multiply very fast to form huge populations which express the desired gene.

• 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: Mast cells in the human body release excessive amounts of inflammatory chemicals which cause allergic reactions.

Reason: Allergens in the environment on reaching human body stimulate mast cells in certain individuals.

• 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: Parturition is induced by neural signal in maternal pituitary.

Reason: At the end of gestation period, the maternal pituitary releases prolactin which causes uterine contractions.

• 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.