Three forms of dextrans namely neutral, polyanionic and polycationic having different molecular radii were injected separately in three groups of rats. The concentrations dextrans in glomerular filtrate were measured to determine the filterability of the dextrans. The possible outcomes could be as follows:

(A) The dextrans having smaller diameter have greater filterability than large dextrans.

(B) Neutral dextrans were filtered more than polycationic and polyanionic dextrans.

(C) Polycationic dextrans were filtered more than neutral and polyanionic dextrans.

(D) Polyanionic dextrans were filtered more than neutral and polycationic dextrans.

Which one of the following combinations is correct?

• (A) only

• (B) only

• (A) and (C)

• (B) and (D)

The fungus associated with human oral or vaginal infection is

• Fusarium

• Aspergilus

• Candida

• Pneumocytis

53.

A neuron that fires when an individual is eating by hand, also fires when he sees someone else eating with hand. Such neurons are called

• mirror neurons

• mimicry neurons

• motor neurons

• reward neurons

A patient has episodes of painful spontaneous muscle contraction, followed by periods of paralysis of the affected muscles. It was identified as primary hyperkalemic paralysis, an inherited disorder. The possible causes of the paralysis are:

A. The elevation of extracellular K⁺ causes hyperpolarization of skeletal muscle cells.

B. The hyperpolarization of the muscle cell membrane inactivates sodium channels.

C. The elevation of extracellular K⁺ causes depolarization of skeletal muscle cells.

D. Ths sodium channels are voltage inactivated in depolarized state.

Which one of the following is true?

• Only A

• A and B

• Only C

• C and D

Maintaining the salt concentration and volume of plasma are two key parameters for physiological processes achieved by kidney. Which of the following structural and functional combines is the most efficient renal regulatory system in mammals?

• Structural	Functionsl
  Large glomerulus, long proximal and distal tubules, long Henle's loop	Transepithelial potential in proximal tubule countercurrent multiplier, ADH responsiveness of distal tubule

• Small glomerulus, short proximal and distal tubule short Henle's loop

  Transepithelial potential in distal tubule, very high ADH concentration in circulation

• Very large glomerulus, short proximal tubule, very long distal tubule, long Henle's loop

  Very efficient glomerular filtration, prevention of solute loss

• Small glomerulus, long proximal and distal tubules, Henle's loop

  Preventing water and solute filtration, excreting solute, lowering ADH responsiveness.

Which one of the following graphs best represents the hormone profile in a rat right after mating?

One hemoglobin molecule containing four heme groups can bind with four O₂. The reactions of Hb and O₂ are shown below:

Which one of the following reactions is fastest?

• Hb₄ + O₂ $\rightleftharpoons$ Hb₄O₂

• Hb₄O₂ + O₂ $\rightleftharpoons$ Hb₄O₄

• Hb₄O₄ + O₂ $\rightleftharpoons$ Hb₄O₆

• Hb₄O₆ + O₂ $\rightleftharpoons$ Hb₄O₈

Which one of the following is required to anchor the synaptic vesicles to the cytoskeletal proteins in the pre-synaptic nerve terminals?

• Syntaxin

• Synaptobrevin

• Synaptotagmin

• Synapsin

Respiration can be inhibited voluntarily for some time. the point at which respiration cannot be voluntarily inhibited is known as breaking point. Following explanations are offered for the breaking point:

A. J-receptors stimulate respiratory centers.

B. Hering-Breuer reflex operates.

C. The rise of arterial pCO₂ stimulates the respiratory center.

D. The fall of arterial pO₂ stimulates the respiratory center.

Which of the above combination is correct?

• A and B

• B and C

• C and D

• A and D

A mechanical pressure was exerted on a specific location of a peripheral nerve of a mammal. the touch or pain receptors were stimulated from the skin surface innervated by the same nerve. The action potential generates by touch receptor stimulation was blocked beyond the point of mechanical pressure. But the action potential generated by pain receptor stimulation passes through the point of mechanical pressure.

Following explanations were offered for these observations:

A. The large diameter 'A' fibres were affected by mechanical pressure.

B. The small diameter 'C' fibres were not affected by mechanical pressure.

C. The intermediate diameter 'B' fibres were affected by mechanical pressure.

D. The large diameter 'A' fibres were not affected by mechanical pressure.

Which of the above combinations is correct?

• A and B

• B and C

• C and D

• A and D