All Free Biology MCQs with Answers

• A. Uterine contraction
• B. Growth of the body
• C. Blood pressure
• D. Production of thyroid hormone

Explanation: STH (Somatotrophic Hormone) also known as the growth hormone is secreted by the anterior pituitary gland has a direct effect on the growth of the body. It also controls metabolism. The production of thyroid hormone is controlled by Thyroid Stimulating Hormone (TSH) secreted by the anterior pituitary gland. Uterine contractions are a result of the secretion of oxytocin by the posterior lobe of the pituitary gland. Blood pressure is controlled by various factors, however, vasopressin also plays a role in blood pressure control.

• A. Calcium
• B. Carbondioxide
• C. Oxygen
• D. Vitamin D

Explanation: Parathormone acts on kidneys and releases the active form of vitamin D. When it acts on bones, it release calcium. Another function of parathormone is to increase the phosphate excretion or decrease the reabsorption of it through acting on the kidneys.

• A. Glucagon
• B. Estrogen
• C. Insulin
• D. Progesterone

Explanation: Glucagon is a hormone produced by the pancreas that increases blood glucose levels by promoting the breakdown of Glycogen (stored glucose) in the liver and the production of Glucose from amino acids in the liver. Cortisol increases the function of glucagon to convert glycogen into glucose, increasing blood glucose levels.

• A. Carbohydrates
• B. Proteins
• C. Lipids
• D. Nucleic Acids

Explanation: Insulin and glucagon are both peptide (protein) hormones secreted by the beta and alpha cells of pancreas respectively.

• A. Release factor
• B. Inhibitor
• C. Accelerator
• D. Tropic or trophic hormones

Explanation: Hormones secreted by the anterior pituitary that control the secretion of hormones from other endocrine glands are known as tropic or trophic hormones. These hormones include thyroid-stimulating hormone (TSH), adrenocorticotropic hormone (ACTH), follicle-timulating hormone (FSH), and leutinizing hormone (LH). They stimulate the target glands to produce and release their own hormones, thereby controlling their activity and function.

• A. Glucocorticoid
• B. Insulin
• C. Glucagon
• D. Aldosterone

Explanation: The correct answer is Glucagon. It is a peptide hormone secreted by the alpha cells of the Islets of Langerhans in the pancreas. Glucagon's primary function is to increase blood sugar levels by promoting the breakdown of glycogen to glucose in the liver. This process helps maintain blood glucose homeostasis, especially during fasting states. On the other hand, Glucocorticoids and Aldosterone are hormones produced by the adrenal cortex, unrelated to the Islets of Langerhans. Insulin is secreted by the beta cells of the Islets of Langerhans and works oppositely to glucagon by lowering blood sugar levels.

• A. Grave's disease
• B. Goiter
• C. Hyperglycemia
• D. Dwarfism

Explanation: Hyperglycemia is caused by under production of insulin hormone. Option B is correct as iodine deficiency is the most common cause of goiter. The body needs iodine to produce thyroid hormone. If you do not have enough iodine in your diet, the thyroid gets larger to try and capture all the iodine it can, so it can make the right amount of thyroid hormone.

• A. Parathormone
• B. Adrenaline
• C. Thyroxin
• D. Thiamin
• E. Prolactin

Explanation: Circulating parathyroid hormone targets the distal convoluted tubule and collecting duct, directly increasing calcium reabsorption.

• A. Prolactin
• B. LH (Luteinizing Hormone)
• C. FSH (Follicle-Stimulating Hormone)
• D. Oxytocin

Explanation: Oxytocin is the hormone released by the posterior pituitary that stimulates the contraction of uterine(during labor) and mammary gland muscles.

• A. Glucagon
• B. Thyroxine
• C. Epinephrine
• D. Oestrogen

Explanation: Estrogen is a female sex hormone that is steroid in nature.