471.Denaturation of double stranded DNA results in

a.It gets broken down to nucleotides.
b.It becomes single stranded reversibly.
c.Becomes single stranded iireversibly.
d.Becomes double stranded permanently.

Ans-b.It becomes single stranded reversibly.

470.All potentiate digoxin toxicity except

a.Hyperkalemia
b.Hypomagnesia
c.Hypercalcemia
d.Renal failure

Ans-a.Hyperkalemia
 Ref-Katzung pg 54-55   10th ed
Hyperkalemia is a protective factor as in the presence of hyperkalemia,the binding of digoxin becomes less

469.Substance P is released in response to pain in periphery

a.Nerve terminalis
b.Mast cells
c.Endothelium
d.Plasma

Ans-a.Nerve terminalis

Ref -Ganong's review of medical physiology 23 rd ed pg 112