Tiêu đề Chemical Coordination and integration EX-2 Solution fie.docx.pdf ✅

41 CHEMICAL COORDINATION AND INTEGRATION EXERCISE–2: Previous Year Competition Questions 1. Erythropoietin hormone which stimulates R.B.C. formation is produced by: [NEET 2021] (a) Alpha cells of pancreas (b) The cells of rostral adenohypophysis (c) The cells of bone marrow (d) Juxtaglomerular cells of the kidney Ans. (d) Sol. The juxtaglomerular cells of kidney produce a peptide hormone called erythropoietin which stimulates erythropoiesis (formation of RBC). 2. Match the following columns and select the correct option. [NEET 2020] Column I Column II (a) Pituitary gland (i) Grave’s disease (b) Thyroid gland (ii) Diabetes mellitus (c) Adrenal gland (iii) Diabetes insipidus (d) Pancreas (iv) Addison’s disease (a) a – iii; b – i; c – iv; d – ii (b) a – ii; b – i; c – iv; d – iii (c) a – iv; b – iii; c – i; d – ii (d) a – iii; b – ii; c – i; d – iv Ans. (a) Sol. The antidiuretic hormone released by the pituitary gland stimulates reabsorption of water by the kidneys. The deficiency of this hormone causes increased urine production, a condition called diabetes insipidus. Grave’s disease is an immune system disorder that results in the overproduction of thyroid hormones. Addison's disease is caused by a deficiency of the hormones secreted by the adrenal cortex. Pancreas is a composite gland which acts as both exocrine and endocrine gland. The deficiency of insulin, a hormone secreted by the pancreas, causes a complex disorder called diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies. 3. Select the correct statement. [NEET 2020] (a) Insulin acts on pancreatic cells and adipocytes. (b) Insulin is associated with hyperglycemia. (c) Glucocorticoids stimulate gluconeogenesis. (d) Glucagon is associated with hypoglycemia. Ans. (c) Sol. -Insulin acts mainly on hepatocytes and adipocytes (cells of adipose tissue) and enhances cellular glucose uptake and utilization. -Glucagon acts mainly on the liver cells (hepatocytes) and stimulates glycogenolysis resulting in an increased blood sugar (hyperglycemia). -Glucocorticoids stimulate, gluconeogenesis, lipolysis and proteolysis and inhibit cellular uptake and utilization of amino acids. -Insulin enhances cellular glucose uptake and utilization and as a result, there is a rapid movement of glucose from blood to hepatocytes and adipocytes resulting in decreased blood glucose levels (hypoglycemia). 4. Match the column and select the correct option. [NEET 2020] Column I Column II (a) Pituitary gland (i) Steroid (b) Epinephrine (ii) Neuropeptide (c) Endorphins (iii) Peptide, protein (d) Cortisol (iv) Biogenic amines (a) a-iv, b-i, c-ii, d-iv (b) a-iii, b-iv. c-ii, d-i (c) a-iv, b-iii, c-i, d-ii (d) a-iii, b-iv, c-i, d-ii Ans. (b) Sol. Pituitary glands produce the hormone which are proteins and peptides. Epinephrine is derived from amino acid tyrosine. Endorphins are the peptide hormones that are naturally produced by the brain in conditions of pain and stress. Cortisol is a steroid hormone produced from adrenal cortex. 5. Hormones stored and released by neurohypophysis are [NEET 2020] (a) Thyroid stimulating hormone and oxytocin (b) Oxytocin and vasopressin (c) Follicle stimulating hormone and luteinizing hormone (d) Prolactin and vasopressin Ans. (b) Sol. The posterior pituitary is mainly a collection of axonal projections from the hypothalamus that terminates behind the anterior pituitary. It secretes
42 CHEMICAL COORDINATION AND INTEGRATION the neurohypophysial hormone i.e., oxytocin and vasopressin directly into the blood. 6. How does steroid hormone influence cellular activities? [NEET 2019] (a) Binding to DNA and forming a gene-hormone complex (b) Activating cyclic AMP located on the cell membrane. (c) Using aquaporin channels as second messenger (d) Changing the permeability of the cell membrane. Ans. (a) Sol. Steroid hormones directly enter into the cell and bind with intracellular receptors in nucleus to form hormone receptor complex. Hormone receptor complex interacts with the genome. 7. Match the following hormones with the respective disease. [NEET 2019] (p) Insulin (i) Addison’s disease (q) Thyroxin (ii) Diabetes insipidus (r) Corticoids (iii) Acromegaly (s) Growth Hormones (iv) Goitre (v) Diabetes mellitus Select the correct option. (a) p → (ii); q → (iv); r → (iii); s → (i) (b) p → (v); q → (iv); r → (i); s → (iii) (c) p → (ii); q → (iv); r → (i); s → (iii) (d) p → (v); q → (i); r → (ii); s → (iii) Ans. (b) Sol. -Insulin deficiency leads to diabetes mellitus. -Hypersecretion or hyposecretion of thyroxine can be associated with enlargement of thyroid gland called goiter. -Deficiency of corticoids (Glucocorticoid + mineralocorticoid) leads to Addison's disease. -Growth hormone hypersecretion in adults leads to acromegaly. 8. Which of the following glucose transporters is insulin dependent? [NEET 2019] (a) GLUT I (b) GLUT II (c) GLUT III (d) GLUT IV Ans. (d) Sol. The GLUT family is divided into three classes based on their sequence homology. The physiological roles of class I GLUTs, 1, 2, 3 and 4 have been extensively studied for their contribution to metabolism and development. A) GLUT I facilitate the transport of glucose across the plasma membrane. GLUT I is insulin-independent, and it can meet the basic needs of muscle cells. between liver and blood and it is also insulin- independent. C) GLUT III transports glucose into brain cells at a rate that is independent of plasma level of glucose. It is also insulin- independent. D) GLUT IV is the insulin-regulated glucose transporter found primarily in adipose tissues and striated muscles. 9. Which of the following hormones is responsible for both milk ejection reflex and foetal ejection reflex? [NEET 2019] (a) Estrogen (b) Prolactin (c) Oxytocin (d) Relaxin Ans. (c) Sol. Foetal ejection reflex in human females is induced by the release of oxytocin from the pituitary. The signals for parturition originate from a fully developed foetus and the placenta of the mother, which induces mild uterine contractions called foetal ejection reflex. In foetal ejection reflex, the oxytocin hormone is secreted by the paraventricular nuclei of the hypothalamus. This hormone is also known as a birth hormone or milk ejection hormone. This oxytocin hormone acts on the uterine muscle and causes stronger contractions, which in turn stimulates further secretion of oxytocin. 10. Identify A, B and C in the diagrammatic representation of the mechanism of hormone action. [NEET 2019] Select the correct option from the following. (a) A- steroid hormones, B- Hormone receptor complex, C- Protein
43 CHEMICAL COORDINATION AND INTEGRATION (b) A- Protein hormone, B- Receptor, C- Cyclic AMP (c) A- Steroid hormone, B- Receptor, C- Second messenger (d) A- Protein hormone, B- Cyclic AMP, C- Hormone receptor complex Ans. (b) Sol. A is the protein hormone that binds to the receptor represented as B. This bind of the hormone with its receptor will lead to the production of a secondary messenger called cyclic AMP represented as C. 11. Artificial light, extended work time and reduced sleep time disrupt the activity of [NEET 2019] (a) Thymus gland (b) Adrenal gland (c) Pineal gland (d) Posterior pituitary gland Ans. (c) Sol. Pineal gland produces a hormone called melatonin that maintains the biological clock and sleep wake pattern of the body. This hormone is sensitive to bright artificial light. Its production is also hampered during extended work time and reduced sleep. 12. Which of the following conditions will stimulate parathyroid gland to release parathyroid hormone? [NEET 2019] (a) Fall in active vitamin D levels (b) Fall in blood Ca 2+ levels (c) Fall in bone Ca 2+ levels (d) Rise in blood Ca 2+ levels Ans. (b) Sol. If calcium blood levels are too low, your parathyroid glands will release PTH into the blood. This causes calcium levels to rise. If calcium blood levels are too high, these glands will stop secreting PTH. 13. Which of the following is an amino acid derived hormone? [NEET 2018] (a) Estradiol (b) Ecdysone (c) Epinephrine (d) Estriol Ans. (c) Sol. Epinephrine is an amino acid derivative hormone. It is also known as adrenaline. Epinephrine acts as a neurotransmitter which belongs to a class of compound called catecholamine. It is a hormone secreted by the medulla of adrenal glands. Epinephrine is derived from an amino acid called tyrosine. Other three remaining hormones are steroid hormones. Hence, option (c) is correct. 14. Which of the following hormones can play a significant role in osteoporosis? [NEET 2018] (a) Estrogen and parathyroid hormone (b) Progesterone and aldosterone (c) Aldosterone and prolactin (d) Parathyroid hormone and prolactin Ans. (a) Sol. Estrogen and parathyroid hormones play a significant role in osteoporosis. Estrogen deficiency can cause excessive bone resorption accompanied by inadequate bone formation. In case of parathyroid hormone, when one of the parathyroid glands show overactivity known as hyperparathyroidism, then the parathyroid gland makes too much parathyroid hormone which causes the bone to release calcium constantly into the bloodstream which causes the loss of density and hardness of bones. 15. A temporary endocrine gland in the human body is [NEET 2017] (a) Pineal gland (b) Corpus cardiacum (c) Corpus luteum (d) Corpus allatum Ans. (c) Sol. A temporary endocrine gland in the body is the corpus luteum. The corpus luteum is a transient endocrine gland that differentiates from the ovulatory follicle midway through the menstrual cycle. It is a mass of cells that forms in an ovary and is responsible for the production of the hormone progesterone during early pregnancy. 16. GnRH a hypothalamic hormone, needed in reproduction acts on [NEET 2017] (a) Anterior pituitary gland and stimulates secretion of LH and oxytocin. (b) Anterior pituitary gland and stimulates secretion of LH and FSH. (c) Posterior pituitary gland and stimulates secretion of oxytocin and FSH. (d) Posterior pituitary gland and stimulates secretion of LH and relaxin. Ans. (b) Sol. GnRH, a hypothalamic hormone needed in reproduction, acts on the anterior pituitary gland, and stimulates the secretion of luteinizing hormone and
44 CHEMICAL COORDINATION AND INTEGRATION follicle-stimulating hormone. It is a tropic peptide hormone synthesized and released from the neurons of GnRH within the hypothalamus. It is the key regulator of the reproductive axis. 17. Hypersecretion of growth hormone in adults does not cause further increase in height because [NEET 2017] (a) Growth hormone become inactive in adults (b) Epiphyseal plates close after adolescence. (c) Bones lose their sensitivity to growth hormone in adults. (d) Muscle fibres do not grow in size after birth. Ans. (b) Sol. Hypersecretion of growth hormone in adults does not cause a further increase in height because the epiphyseal plate gets closed after adolescence. The epiphyseal plate also called the growth plate is a hyaline cartilage plate in the metaphysis at each end of a long bone. Growth plates usually get closed near the end of puberty. 18. Which of the following pairs of hormones are not antagonistic (having opposite effects) to each other? [NEET 2016] (a) Parathormone - Calcitonin (b) Insulin - Glucagon (c) Aldosterone - Atrial Natriuretic Factor (d) Relaxin - Inhibin Ans. (d) Sol. The relaxin hormone is not the antagonist of inhibin. Relaxin is a peptide hormone secreted by the placenta. It is responsible for the dilation in the cervix and aids in childbirth. Inhibin is secreted from ovaries, and it inhibits the release of FSH i.e., follicle-stimulating hormone. 19. Changes in GnRH pulse frequency in females is controlled by circulating levels of [NEET 2016] (a) Estrogen and progesterone (b) Estrogen and inhibin (c) Progesterone only (d) Progesterone and inhibin Ans. (a) Sol. Changes in GnRH pulse frequency in females is maintained by circulating levels of estrogen and progesterone. These hormones are female sex hormones, and they are produced mainly by the ovaries i.e., the female gonads. These two hormones are important for normal reproductive development and fertility. 20. The amino acid tryptophan is the precursor for the synthesis of [NEET 2016] (a) Melatonin and Serotonin (b) Thyroxine and Triiodothyronine (c) Estrogen and Progesterone (d) Cortisol and Cortisone Ans. (a) Sol. The amino acid tryptophan is the predecessor for the synthesis of melatonin and serotonin hormone. These two are neurotransmitters. Within the pineal gland, the hormone serotonin is acetylated and then methylated to yield melatonin. Melatonin is a hormone released by the pineal gland that regulates the sleep-wake cycle. Serotonin is called a happy chemical because it contributes to well-being and happiness. 21. Grave’s disease is caused due to [NEET 2016] (a) Hyposecretion of thyroid gland (b) Hypersecretion of thyroid gland (c) Hyposecretion of adrenal gland (d) Hypersecretion of adrenal gland Ans. (b) Sol. Grave’s disease is caused due to hypersecretion of thyroid glands. It is an autoimmune condition where the immune system attacks the thyroid by mistake which causes it to become overactive. Grave’s disease is also known as toxin diffuse goitre. It affects women more than men. 22. Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilization. [NEET 2016] (a) Insulin (b) Glucagon (c) Secretin (d) Gastrin Ans. (a) Sol. Insulin is a peptide hormone that acts mainly on hepatocytes, adipocytes, and enhances cellular glucose uptake and utilization. Insulin maintains the blood glucose levels by signaling the liver, muscle, and fat cells to take in glucose from the blood. Insulin is produced by the beta cells of islets of Langerhans in the pancreas and considered to be the main anabolic hormone of the body.