Multiple Choice Questions

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Achondroplasia is a disease related with the defect in the formation of

  • membrane

  • cartilage

  • mucosa

  • none of these


B.

cartilage

Achondroplasia is a disorder inherited as dominant characteristic in which bones of arms and legs fail to grow to normal size due to defect in both cartilage and bone. It results in a type of dwarfism characterised by short limbs, a normal sized head and body and normal intelligence.


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Unidirectional transmission of a nerve impulse through nerve fibre is due to the fact that

  • nerve fibre is insulated by a medullary sheath

  • sodium pump starts operating only at the cyton and then continues into the nerve fibre

  • neurotransmitters are released by dendrites and not by axon endings

  • neurotransmitters are released by the axon endings and not by dendrites.


Pacinian corpuscles occur in the skin of certain parts of body in mammals. These are

  • type of glands

  • pain receptors

  • naked tactile receptors

  • encapsulated pressure receptors.


Wharton's duct is the duct of

  • submandibular salivary gland

  • parotid gland

  • sublingual gland

  • all of these


An artificial pacemaker is implanted subcutaneously and connected to the heart in patients

  • having 90% blockage of the three main coronary arteries

  • having a very high blood pressure

  • with irregularity in the heart rhythm

  • suffering from arteriosclerosis


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C4 plants have better productivity because

  • C4 plants absorb more light

  • C4 plants absorb more CO2

  • C4 plants lack photorespiration

  • all of these


Assertion: Photorespiration is a wasteful process where there is no synthesis of ATP energy.

Reason: RuBisCO is present in mesophyll cells of C4 plants hence they show more 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.


The checkpoint in cell cycle plays important role in

  • repairing DNA damage

  • apoptosis initiation

  • assessing DNA damage

  • none of these


Which part of the nephron is impermeable to water

  • Proximal convoluted tubule

  • Distal convoluted tubule

  • Ascending limb of loop of Henle

  • Descending limb of loop of Henle


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Pick the correct group consisting of all genera exhibiting homospory

  • Lycopodium, Psilotum, Selaginella, Equisetum

  • Equisetum, Pteris, Salvinia, Psilotum

  • Salvinia, Pteris, Lycopodium, Selaginella

  • Equisetum, Psilotum, Lycopodium, Pteris