Hyposecretion of what hormone could cause the symptoms of low basal metabolic rate, weight gain, fatigue, slowed heart rate, depression, constipation, memory problems, and lethargy along with a decreased ability to adapt to cold stress.

Thyroid hormone

Explanation:

Thyroid hormone whose main function  is to regulate the body metabolism is secreted by the thyroid gland. Insufficient or low secretion (Hyposecretion) of this hormone will lead to decrease in basal metabolic rate

1 digestive system

2 stomach

3 bladder

4 carbon deoxide

5 tiger