Correct option is B
Explanation-
Statement A - A thermogenic uncoupling protein, UCP1 helps in the heat production in BAT - CORRECT
UCP1 (uncoupling protein 1), found in the inner mitochondrial membrane of BAT, uncouples oxidative phosphorylation from ATP synthesis, dissipating the proton gradient as heat instead of producing ATP.
Statement B - Norepinephrine secretion from sympathetic nerve endings in BAT is decreased - INCORRECT
In cold conditions, norepinephrine (NE) secretion actually increases, not decreases. NE stimulates β-adrenergic receptors on brown adipocytes, triggering thermogenesis and lipolysis.
Statement C - Lipolysis is increased by low level of norepinephrine in BAT - INCORRECT
This is incorrect on two counts , first of all low levels of NE do not stimulate lipolysis effectively. High levels of NE stimulate β-adrenergic receptors, increasing lipolysis, which provides fatty acids that activate UCP1.
Statement D - A high content of mitochondria in BAT helps in the oxidation of fatty acids - CORRECT
BAT is rich in mitochondria, which oxidize fatty acids to produce heat through UCP1 action.
Statement E - Oxidation produces much heat as ATP synthase activity is low - CORRECT
In BAT, due to UCP1 activity, proton gradient is not used for ATP synthesis, resulting in heat production instead. Hence, ATP synthase activity is low, but oxidation still occurs, leading to thermogenesis.
Correct statements: A, D, and E
So, correct option is Option b (A, D, and E)
