All Free Biology MCQs with Answers
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19844 questions · page 707 of 1985
7061. Regulates blood sugar levels
- A. Pancreas
- B. Thyroid
- C. Anterior pituitary
- D. Posterior pituitary
Explanation: The pancreas is a gland that plays a dual role in the digestive system and endocrine system
Correct answer: Pancreas7062. Bridge between nervous and endocrine systems
- A. Pancreas
- B. Thyroid
- C. Anterior pituitary
- D. Posterior pituitary
- E. Hypothalamus
Explanation: Hypothalamus:The hypothalamus is a region in the brain that acts as a control center for many physiological processes.It serves as a link between the nervous system and the endocrine system.It produces releasing hormones that stimulate the pituitary gland to release other hormones.It also receives signals from the nervous system about things like blood sugar levels and relays that information to the endocrine system.
Correct answer: Hypothalamus7063. A tumor in beta cells would result in all of the following except:
- A. More insulin production
- B. Low blood glucose
- C. Destruction of alpha cells
- D. Low calcium in blood
Explanation: The beta cells regulate blood glucose through insulin secretion. They are not involved in calcium regulation, so a tumor here would not cause low calcium.
Correct answer: Low calcium in blood7064. Destruction of all beta cells in the pancreas would cause:
- A. Glucagon secretion to stop and a decrease in blood glucose
- B. Glucagon secretion to stop and an increase in blood glucose
- C. Insulin secretion to stop and an increase in blood glucose
- D. Insulin secretion to stop and a decrease in blood glucose
Explanation: The beta cells produce insulin, which lowers blood glucose. Without insulin, glucose remains high, leading to hyperglycemia.
Correct answer: Insulin secretion to stop and an increase in blood glucose7065. α-cells of the pancreas secrete a hormone known as:
- A. Glucagon
- B. Gastrin
- C. Insulin
- D. Rennin
Explanation: Alpha cells secrete glucagon, a catabolic hormone that increases blood glucose and fatty acid levels, opposing insulin.
Correct answer: Glucagon7066. Which of the following is not secreted by thyroid gland?
- A. Thyroxine
- B. Triiodothyronine
- C. Calcitonin
- D. Glucagon
Explanation: The thyroid gland secretes T3, T4, and calcitonin. Glucagon is secreted by pancreatic alpha cells.
Correct answer: Glucagon7067. _ hormone is antagonistic to insulin and causes an increase in blood glucose levels.
- A. Glucagon
- B. Calcitonin
- C. Nor-epinephrine
- D. Thyroxine
Explanation: Beta cells of the islets of Langerhans secrete insulin, which lowers blood glucose by increasing uptake and storage in cells.
Correct answer: Glucagon7068. Beta cells of islets of Langerhans produce _ hormone.
- A. Glucagon
- B. Pancreatic juice
- C. Insulin
- D. Parathormone
Explanation: Beta cells of the islets of Langerhans secrete insulin, which lowers blood glucose by increasing uptake and storage in cells.
Correct answer: Insulin7069. Excess glucose is converted in the liver to glycogen in response to the hormone:
- A. Glucagon
- B. Insulin
- C. Bile
- D. Both A and B
Explanation: Insulin promotes glycogenesis in the liver and muscles, storing excess glucose as glycogen when blood sugar levels are high.
Correct answer: Insulin7070. Which of the following acts as a messenger in both chemical and nervous coordination?
- A. Acetylcholine
- B. Nicotine
- C. Dopamine
- D. Epinephrine
Explanation: Epinephrine (adrenaline) acts as both a neurotransmitter and a hormone, mediating nervous and endocrine responses in "fight or flight."
Correct answer: Epinephrine