A peptide hormone binds a membrane receptor and activates a second messenger. This mechanism is needed because peptide hormones:
Correct Answer: A. Usually cannot pass freely through lipid membranes
MCQ Collection
Animal Form and Function-I MCQs
Practice Animal Form and Function-I questions with answers and explanations.
A student asks why hormone levels are measured in blood. The reason is that most vertebrate hormones:
Correct Answer: A. Are transported through the bloodstream
A fish has a two-chambered heart. Blood passes through the heart once per circuit, known as:
Correct Answer: A. Single circulation
A hormone that increases water reabsorption in kidneys helps prevent dehydration. In mammals this function is associated with:
Correct Answer: A. Antidiuretic hormone
A steroid hormone affects transcription slowly. Its effect may last longer because it changes:
Correct Answer: A. Gene expression and protein synthesis
A gland secretes digestive enzymes into a duct. It is not endocrine because its secretion:
Correct Answer: A. Does not enter blood as a hormone directly
A frog has a three-chambered heart. Compared with fish, this supports:
Correct Answer: A. Partial separation of oxygenated and deoxygenated blood
A student connects the hypothalamus and pituitary. The hypothalamus is important because it:
Correct Answer: A. Controls many pituitary hormone secretions
A student compares endocrine and exocrine glands. Sweat glands are exocrine because they:
Correct Answer: A. Secrete through ducts onto a surface
A student studies hormone feedback in thyroid regulation. High thyroxine usually reduces:
Correct Answer: A. TSH release
Birds and mammals maintain high metabolic rates partly because their hearts have:
Correct Answer: A. Four chambers with complete blood separation
A pituitary hormone stimulates the thyroid gland. This hormone is:
Correct Answer: A. TSH