You receive two samples from two different species: one gram of live tissue each. You measure the basal metabolic rate (BMR) of each and sample A has a much higher BMR than sample B. What can you say about the mass of the animals the samples came from

Explanation:

1. Basal metabolic rate (BMR ), At rest, the metabolic rate is known as the basal metabolic rate (BMR). And at rest, the BMR is low compared to when the body is undergoing activities like exercise .

2. During this resting state the body needs to use energy  only  to keep vital organs such as the heart, lungs and brain working properly.

3. The metabolic rate can be measured in many different ways:

i) Oxygen consumption ,  ii) Carbon dioxide production and iii) Heat production.

4. As a general rule for BMR, the greater the mass of an organism the higher that organism’s metabolic rate is. It is the amount of energy cell or organism spends at the resting stage. The more the BMR then more the person becomes weak and lean. So, since sample A has more BMR this means that the person A is lean or thin as compared to person B.

5. So, BMR is higher per unit of body mass in small animals compared to larger animals, because the higher metabolic rate of small animals needs a greater delivery of oxygen to tissues around the body.