Final answer:
The expected symptoms in a hypophysectomized rat are most likely related to hypothyroidism, which include a decreased metabolic rate and lethargy due to the removal of the pituitary gland and the resulting lack of thyroid stimulating hormone.
Step-by-step explanation:
The question pertains to the symptoms that might be expected as a result of missing certain hormones in a hypophysectomized rat, meaning a rat that has had its pituitary gland removed. Given that the pituitary gland plays a vital role in regulating a variety of hormones that affect growth, metabolism, and blood sugar levels, the symptoms that can be seen in such a rat relate to those regulatory activities.
Considering the options provided, the correct answer is C) Decreased metabolic rate and lethargy. This is because after the removal of the pituitary gland (hypophysectomy), there would be a lack of thyroid stimulating hormone (TSH), which would lead to hypothyroidism. Hypothyroidism is characterized by a decreased metabolic rate, weight gain, cold sensitivity, and reduced mental activity among other symptoms.