Multiple Choice Questions

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Assertion: Nitrogen is one of the most essential elements of human body.

Reason: All types of prokaryotic organisms are able to fix nitrogen.

  • 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.


C.

If assertion is true but reason is false. 

Nitrogen is one of the most essential elements of human body. It is a constituent of a number of organic compounds like amino acids, proteins, nucleotides, nucleic acids, many vitamins, hormones etc. Biological N2 fixation is a very important natural process which is performed by two types of prokaryotes - bacteria and cyanobacteria. They include both free living and symbiotic forms.


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Assertion: Branchiostoma and Balanoglossus are bilaterally symmetrical and triploblastic animals.

Reason: They are exclusively marine and possess notochord.

  • 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: 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: Blood in cockroach is colourless haemolymph with no respiratory pigment.

Reason: Respiration in cockroach occurs through diffusion in haemolymph.

  • 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 light reaction of photosynthesis, light is required for the functioning of PS I and PS II, and production of NADPH and ATP.

Reason: Dark reaction does not occur in light.

  • 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.


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Assertion: ADH and RAAS work in response to low blood volume and blood pressure.

Reason: ANF works in response to high blood volume and blood pressure.

  • 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: The nymph of a cockroach undergoes moulting several times.

Reason: There is gradual metamorphosis in cockroach.

  • 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: Secondary metabolites are produced in small quantities and their extraction from the plant is difficult and expensive.

Reason: Secondary metabolites can be commercially produced by using tissue culture technique.

  • 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.


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Assertion: Cephalisation is advantageous to an animal.

Reason: It improves the appearance of the animal.

  • 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.