Competitive Exams: Zoology MCQs (Practice-Test 5 of 112)

  1. Nitric oxide inflates the process leading to dilatation of blood vessels by activating

    1. guanylyl cyclase

    2. ATPase

    3. MOA

    4. AchE

  2. Diuresis is the condition in which the

    1. water balance of blood is disturbed

    2. kidney fails to excrete urine

    3. volume of urine excreted increases

    4. volume of urine excreted decreases

  3. Which one of the following is NOT involved in overcoming the osmoregulatory difficulties in marine teleosts?

    1. Reduction in the osmotic gradient between the body fluids and the environment

    2. Alteration in the body-surface permeability

    3. Active transport of ions into or out of the animal as required

    4. Alteration in the rate of blood circulation

  4. Consider the following statements:

    1. Oxygenases

    2. Oxidases

    3. Dehydrogenases

    4. Peroxidases

    Which of these enzymes are involved in the transfer of electrons of the hydrogen atoms of the substrate to oxygen and removal of hydrogen from the substrate and passing it directly to oxygen?

    1. 1 and 4

    2. 2 and 4

    3. 1 and 3

    4. 2 and 3

  5. Which one of the following groups of amino acids contains sulphur?

    1. Cystine, methionine and cysteine

    2. Arginine, citruline and omithine

    3. Glycine, proline and serine

    4. Leucine, lysine and methionine

  6. The pH of a solution is

    1. log 1 H + ____

    2. log 1--H ± -

    3. log--H ± -

    4. 1 log--H ± -

  7. Which one of the following amino acids lacks an asymmetric alpha-carbon?

    1. Tyrosine

    2. Leucine

    3. Alanine

    4. Glycine

  8. A large meal can make the blood pH alkaline because of

    1. increase in blood sugar

    2. secretion of acid in the stomach

    3. secretion of bicarbonate into blood in exchange of chloride

    4. the alkalinity of the digestion products

  9. If a person has consumed a large amount of meat, his/her urine will eliminate a greater amount of

    1. creatine

    2. urea

    3. glycogen

    4. sodium chloride

  10. Classical gout is the reault of an accumulation of

    1. urea

    2. ammonia

    3. uric acid

    4. alanine

  11. In Krebs cycle, the following reactions are involved in the production of 15 ATP molecules by oxidation of food stuffs:

    1. Oxidation of pyruvic acid to acetyl CoA.

    2. Oxidation of alpha-ketoglutaric acid

    3. Oxidation of isocitrate

    4. Oxidation of malate

    5. Oxidation of succinate

    6. Conversion of succinyl coenzyme A to succinic acid

    The correct sequence of these reactions is

    1. 1, 2, 4, 3, 5, 6

    2. 1, 3, 2, 5, 4, 6

    3. 1, 4, 3, 2, 5, 6

    4. 1, 2, 4, 5, 3, 6

  12. When a person dives deep under water and resurfaces rapidly, which one of the following sequences of events causes decompression sickness?

    1. Increase in pressure-N2 dissolves in blood-Rapid fall in pressure-N2 bubbles in blood

    2. Increase in pressure-Pressure on ear ossicles-Loss of orientation-Imbalance

    3. Fall in pressure-Loss of O2 from blood-Deoxygenation-Fatigue

    4. Increased pressure-Enhanced blood pressure-Headache-Loss of memory

  13. Which one of the following is the correct squence of conduction if impulse of heartbeat?

    1. S-A node-Bundle of His-Purkinje fibres-Heat muscles

    2. S-Anode-Bundle of His-i A-V node-Purkinje fibres-Heart muscles

    3. S-A node-AV node-Purkinje fibres-Bundle of His-i Heart muscles

    4. S-A node-AV node-Bundle of

    His-Purkinje fibres-a Heart muscles

  14. The most active form of Vitamin D which functions as a hormone is

    1. 25-hydroxycholecalciferol

    2. 24, 25-dihydroxycholecalciferol

    3. 21, 25-hydroxycholecalciferol

    4. 1, 25-dihydroxycholecalciferol

  15. During chemical transmission, the following events occur at synaptic junction:

    1. Transmitters cross synaptic cleft and attach to receptors on the post-synaptic neurons

    2. Postsynaptic membranes are depolarized, initiating the impulse

    3. Chemical excitation at the presynaptic terminal and release of neurotransmitters

    4. Immediately after the impulse is triggered, the recovery of pre-and postsynaptic membranes follows and neurotransmitter is destroyed.

    The correct sequence of these events is

    1. 1, 3, 4, 2

    2. 3, 1, 4, 2

    3. 3, 1, 2.4

    4. 1, 3, 2.4