Multiple Choice Questions

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Sympathetic nervous system induces

  • Heartbeat

  • Secretion of digestive juice

  • Secretion of saliva

  • All of the above


A.

Heartbeat

Medulla of brain has two regions affecting heart rate.

(i) Cardiac inhibitory centre.

(ii) Cardiac accelerator centre

Sensory nerves originating from the accelerator centre run parallel to the spinal cord and enter the sino-artial node. Stimulation by these nerves, which are the part of the sympathetic nervous system causes an increase in heartbeat.


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A condition of failure of kidney to form urine is called

  • Deamination

  • Entropy

  • Anuria

  • None of these


Carbon monoxide is a pollutant because it

  • Reacts with oxygen

  • Inhibits glycolysis

  • Reacts with haemoglobin

  • Makes nervous system inactive


The canal system is a characteristic feature of

  • Echinoderms

  • Helminths

  • Coelenterates

  • Sponges


Solenocytes are the main excretory structures in

  • Annelids

  • Molluscs

  • Echinodermates

  • Platyhelminthes


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The contraction of gall bladder is due to

  • Gastrin

  • Secretin

  • Cholecystokinin

  • Enterogastrone


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


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

  • Osmosis

  • Simple diffusion

  • Passive transport

  • Active transport


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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