The gland that is primarily responsible for regulating metabolism is indicated by

Thyroid gland is a gland that plays a major role in regulation of body metabolism and they are also responsible for the development of brain, nervous system in children and bone growth. They release two main hormones which were T3 (tri-iodothyronine) and T4 (Thyroxine). Thyroid gland also helps to maintain digestion, blood pressure, heart rate etc.

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.

the dark variety, as they are not visible on the dark tree barks

explanation: