All Free Biology MCQs with Answers

• A. Pituitary gland
• B. Pancreas
• C. Thyroid gland
• D. Thymus gland
• E. Adrenal gland

Explanation: In humans, prolactin is produced both in the front portion of the pituitary gland (anterior pituitary gland) and in a range of sites elsewhere in the body. Lactotroph cells in the pituitary gland produce prolactin, where it is stored and then released into the bloodstream.

• A. LH hormone
• B. Inhibition hormone
• C. FSH hormone
• D. Testosterone hormone

Explanation: Follicle-stimulating hormone (FSH), the hormone responsible for starting follicle (egg) development, causes the level of estrogen, the primary female hormone, to rise.

• A. Effector
• B. Receptor
• C. Adopter
• D. Stimuli

Explanation: Sensory neurons, also known as afferent neurons, are neurons in the nervous system that convert a specific type of stimulus, via their receptors, into action potentials or graded potentials. This process is called sensory transduction.

• A. Iodopsin glands
• B. Thyroid gland
• C. Rhodopsin glands
• D. Pituitary glands

Explanation: Pituitary gland (also known as hypophysis) is a small, pea-sized gland located at the base of our brain below your hypothalamus. It's a part of our endocrine system and is in charge of making several essential hormones.

• A. fetal adrenal gland
• B. fetal thalamus
• C. fetal hypothalamus
• D. fetal bartholins gland

Explanation: The major corticosteroids aldosterone and cortisol are secreted from the adrenal cortex under the regulation of the renin-angiotensin system and the hypothalamic-pituitary-adrenal axis.

• A. Hypothalamus
• B. Pituitary gland
• C. Thyroid
• D. Thalamus

Explanation: The endocrine system is responsible for producing GnRH. Nerve cells (neurons) in your brain's hypothalamus gland make and release GnRH into your blood vessels. The hormone then travels to your pituitary gland at the base of your brain.

• A. Posterior lobe of pituitary gland
• B. Anterior lobe of pituitary gland
• C. Anterior lobe of thyroid
• D. Exterior lobe of pituitary gland

Explanation: The hypothalamus and the pituitary gland, which are located in the brain, help control the thyroid gland. The hypothalamus releases thyrotropin-releasing hormone (TRH), which stimulates the anterior lobe of the pituitary gland to release thyroid-stimulating hormone (TSH).

• A. Posterior lobe
• B. Both the lobes
• C. None of these
• D. Anterior lobe

Explanation: Thyroid-stimulating hormone is produced and released by the anterior lobe of the pituitary gland.

• A. Grave's disease
• B. Hyperthyroidism
• C. Hypothyroidism
• D. Goitre

Explanation: Undersecretion of thyroxine leads to hypothyroidism, which causes a variety of symptoms such as fatigue, weight gain, and cold intolerance, due to the decreased production of thyroid hormones that regulate metabolism. Grave's disease and hyperthyroidism are associated with excessive hormone production, not undersecretion. Goitre can result from both low and high levels of thyroxine, often related to iodine deficiency or autoimmune conditions, and is not solely indicative of undersecretion.

• A. Increase in Ca levels
• B. Increase in B-12 levels
• C. Decreased Ca levels
• D. Decreased B-12 levels

Explanation: Parathyroid hormone is responsible for maintaining Ca levels in the body. If the parathyroid hormone level is lowered, then so is Ca level. Hence, hypoparathyroidism leads to hypocalcemia.