Multiple Choice Questions

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Carbon monoxide is a pollutant because it

  • Reacts with oxygen

  • Inhibits glycolysis

  • Reacts with haemoglobin

  • Makes nervous system inactive


C.

Reacts with haemoglobin

Carbon monoxide, when inhaled, combines with blood haemoglobin to form carboxyhaemoglobin at a rate 210 times faster than the rate of oxygen forms oxyhaemoglobin. Thus, respiration is impaired.


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A condition of failure of kidney to form urine is called

  • Deamination

  • Entropy

  • Anuria

  • None of these


The canal system is a characteristic feature of

  • Echinoderms

  • Helminths

  • Coelenterates

  • Sponges


The functional unit of the contractile system in striated muscle is

  • Cross Bridge

  • Myofibril

  • Myofibril

  • Z-band


The layer of cells that secrete enamel of the tooth is

  • Dentoblast

  • Ameloblast

  • Osteoblast

  • Odontoblast


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The contraction of gall bladder is due to

  • Gastrin

  • Secretin

  • Cholecystokinin

  • Enterogastrone


Sympathetic nervous system induces

  • Heartbeat

  • Secretion of digestive juice

  • Secretion of saliva

  • All of the above


Solenocytes are the main excretory structures in

  • Annelids

  • Molluscs

  • Echinodermates

  • Platyhelminthes


Calcitonin is a thyroid hormone which

  • Elevates potassium level in the blood

  • Lowers calcium level in a blood

  • Elevates calcium level in the blood

  • Has no effect on calcium


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The exchange of gases in the alveoli of the lungs takes place by

  • Osmosis

  • Simple diffusion

  • Passive transport

  • Active transport