Assertion : Smaller the organism higher is the rate of metabolism per gram weight. Reason : The heart rate of a six month old baby is much lower than that of an old person.

Step-by-step solution

The basal metabolic rate (BMR) is defined as the energy requirement of the human body at rest and reflects the caloric needs of the body. BMR can be determined by total body weight and the amount of muscle mass. BMR is inversely related with the weight or volume of an organism, i.e. smaller the organism, higher is the basal metabolic rate and vice versa. Heart rate of six month old baby is (110-112 ) beats (/ min ). Though it is higher than normal adult person, but it is lower than the old person. At the age of 60