Secretion of aldosterone in birds, man and other mammals is stimulated by
Fall in concentration of $Na^+$ in blood plasma
Rise in concentration of $K^+$ in blood plasma
Both $(a)$ & $(b)$
Fall in $Ca^{++}$ concentration in blood plasma
When a normal heart is injected with physiological concentration of adrenalin, it shows
Which of the following is an emergency hormone
Fightorflight reactions cause activation of
If a human female starts developing male characteristics like beared, degeneration of uterus and ovaries, enlargement of clitoris etc. It may be due to