NEET Previous Year Questions (2016-2024): Chemical Coordination & Integration | Biology Class 11 PDF Download

2024

Q1: Which of the following is not a steroid hormone?      (NEET 2024)
(a) Cortisol
(b) Testosterone
(c) Progesterone
(d) Glucagon
Ans: (d)
Steroid hormones are a class of hormones that are derived from cholesterol and are lipophilic (fat-soluble) in nature. They can easily pass through the cell membranes of target cells to bind with intracellular receptors. Common examples of steroid hormones include cortisol, testosterone, and progesterone, each involved in different regulatory functions in the body.
Cortisol (Option A) is a glucocorticoid hormone produced by the adrenal cortex. It is involved in the regulation of metabolism, immune response, and stress response.
Testosterone (Option B) is an androgen hormone primarily produced in the testes in males and in smaller quantities in the ovaries in females. It plays a key role in developing male reproductive tissues and promoting secondary sexual characteristics such as muscle and bone mass, and the growth of body hair.
Progesterone (Option C) is a hormone released by the ovaries and is important in the regulation of menstruation and maintaining the early stages of pregnancy.
Glucagon (Option D) is fundamentally different from the mentioned hormones. It is a peptide hormone, not a steroid hormone. Glucagon is produced by the alpha cells of the pancreas and works to raise the concentration of glucose in the bloodstream by promoting gluconeogenesis and glycogenolysis in the liver. Unlike steroid hormones, glucagon does not pass through cell membranes but binds to receptors on the cell surface.
Thus, the correct answer to the question is Option D: Glucagon, as it is not a steroid hormone.

Q2: Match List I with List II :           

Choose the correct answer from the options given below :      (NEET 2024)
(a) A-I, B-III, C-II, D-IV
(b) A-IV, B-II, C-I, D-III
(c) A-III, B-IV, C-II, D-I
(d) A-III, B-IV, C-I, D-II
Ans: (d)
To solve the matching question, we need to correctly link each disease (List-I) with their corresponding characteristics (List-II). Here is the breakdown of each disease and its effects:
Exophthalmic goiter: Also known as Graves' disease, this is an autoimmune disorder that involves an overactive thyroid (hyperthyroidism) and is characterized by symptoms such as protruding eyeballs. Therefore, this matches with "Hyper secretion of thyroid hormone & protruding eye balls." - from List II (III).

Acromegaly: This condition is caused by excessive secretion of growth hormone, usually from a benign tumor in the pituitary gland, leading to enlarged features (bones, especially in the hands, feet, and face). Thus, it corresponds with "Excessive secretion of growth hormone." - from List II (IV).
Cushing's syndrome: This syndrome is the result of prolonged exposure to high levels of the hormone cortisol. It features symptoms including obesity majorly centered around the abdomen and upper back, moon face, and hyperglycemia. Therefore, it fits "Excess secretion of cortisol, moon face & hyperglycemia." - from List II (I).
Cretinism: This is a condition arising from the deficiency of thyroid hormone in childhood, which causes impaired neurological function, stunted physical growth, and possibly other symptoms. It matches with "Hypo-secretion of thyroid hormone and stunted growth." - from List II (II).
Now, compare these with the available options:
Therefore, the correct answer is Option D.

Q3: Given below are two statements : one is labelled as Assertion A and the other is labelled as Reason R :      (NEET 2024)
Assertion A : FSH acts upon ovarian follicles in female and Leydig cells in male.
Reason R : Growing ovarian follicles secrete estrogen in female while interstitial cells secrete androgen in male human being.
In the light of the above statements, choose the correct answer from the options given below :
(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true but R is NOT the correct explanation of A
(c) A is true but R is false
(d) A is false but R is true
Ans: (d)
Sol: Statement Assertion A states that "FSH acts upon ovarian follicles in female and Leydig cells in male." To analyze this, we need to examine the role of FSH (Follicle Stimulating Hormone) in both genders.
In females, FSH indeed acts on ovarian follicles. It stimulates the growth and maturation of these follicles, which is critical for oocyte development and estrogen production. Consequently, FSH plays a fundamental role in the menstrual cycle and fertility in females.
In males, however, FSH acts on the Sertoli cells, not the Leydig cells. The function of FSH in males is to promote spermatogenesis by acting on Sertoli cells in the testes, which support the development of sperm. On the other hand, Leydig cells, influenced by Luteinizing Hormone (LH), are responsible for the production of testosterone, a primary male sex hormone.
Moving on to Reason R, which asserts that "Growing ovarian follicles secrete estrogen in female while interstitial cells secrete androgen in male human being." Both parts of this statement are accurate. In females, the growing ovarian follicles indeed secrete estrogen, pivotal in regulating the female reproductive cycle and secondary sexual characteristics. In males, interstitial cells, another term for Leydig cells, produce androgens, like testosterone, vital for male reproductive functions and characteristics.
Given this, Assertion A is false because its statement about FSH acting on Leydig cells in males is incorrect. However, Reason R is true as it accurately describes hormone secretion by ovarian follicles and Leydig cells in females and males, respectively.
Therefore, the correct answer is: Option D: A is false but R is true.

2023

Q1: Which of the following are NOT under the control of thyroid hormone?     (NEET 2023)
A. Maintenance of water and electrolyte balance
B. Regulation of basal metabolic rate
C. Normal rhythm of sleep-wake cycle
D. Development of immune system
E. Support the process of RBCs formation
Choose the correct answer from the options given below:
(a) A and D only
(b) B and C only
(c) C and D only
(d) D and E only
Ans: (c)
Option (C) is the correct answer because thyroid hormones play an important role in the regulation of basal metabolic rate, maintenance of water and electrolyte balance and support the process of RBCs formation, whereas this hormone is not involved in regulating normal rhythm of sleep-wake cycle and development of immune system.

2022

Q1: Which of the following are not the effects of parathyroid hormone?    (NEET 2022 Phase 2)
(A) Stimulates the process of bone resorption.
(B) Decreases Ca²⁺ level in blood.
(C) Reabsorption of Ca²⁺ by renal tubules.
(D) Decreases the absorption of Ca²⁺ from digested food.
(E) Increases metabolism of carbohydrates.
Choose the most appropriate answer from the options given below:
(a) (B), (D) and (E) only
(b) (A) and (E) only
(c) (B) and (C) only
(d) (A) and (C) only
Ans: (a)

• Option (b) is the correct answer because parathyroid hormone is a hypercalcemic hormone, which increases blood calcium levels and the absorption of calcium from digested food. Glucocorticoids regulate carbohydrate metabolism.
• Option (c) is not the answer because parathyroid hormone stimulates the process of bone resorption.
• Option (a) and (d) are not the answers because reabsorption of Ca²⁺ by renal tubules is a function of PTH. 
• Parathyroid hormone (PTH) increases the Ca2+ levels in the blood. PTH acts on bones and stimulates the process of bone resorption (dissolution/ demineralisation). PTH also stimulates reabsorption of Ca2+ by the renal tubules and increases Ca2+ absorption from the digested food. It is, thus, clear that PTH is a hypercalcemic hormone, i.e., it increases the blood Ca2+ levels. Along with TCT, it plays a significant role in calcium balance in the body.
  
  

Q2: Give below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): FSH which interacts with membrane bound receptors does not enter the target cell.
Reason (R): Binding of FSH to its receptors generates second messenger (cyclic AMP) for its biochemical and physiological responses.
In the light of the above statements, choose the most appropriate answer from the options given below
(a) (A) is not correct but (R) is correct
(b) Both (A) and (R) are correct and (R) is the correct explanation of (A)
(c) Both (A) and (R) are correct but (R) is not the correct explanation of (A)
(d) (A) is correct but (R) is not correct   (NEET 2022 Phase 1)
Ans: (c)

• Assertion (A) is correct because FSH, or follicle-stimulating hormone, is a peptide hormone that does not enter the target cell. Instead, it interacts with membrane-bound receptors on the surface of the target cell. This is a common feature of peptide hormones, as they are too large and hydrophilic to pass through the cell membrane.
• Reason (R) is also correct. When FSH binds to its receptor, it triggers a cascade of intracellular events, including the production of second messengers like cyclic AMP (cAMP). The second messengers then go on to activate various biochemical and physiological responses within the target cell, such as cell growth and hormone production. This is a typical process for signal transduction initiated by the binding of a hormone to its cell surface receptor.
• However, (R) is not the correct explanation of (A) because it doesn't directly address why FSH doesn't enter the target cell. The reason FSH does not enter the target cell is that it is a peptide hormone, which cannot cross the cell membrane. Instead, it interacts with cell surface receptors to initiate a signaling cascade. The generation of second messengers, like cAMP, is a part of the signaling process that takes place after FSH binds to its receptor, but it is not the reason why FSH doesn't enter the cell.

2021

Q5: Erythropoietin hormone which stimulates R.B.C. formation is produced by: (NEET 2021)
(a) The cells of bone marrow
(b) Juxtaglomerular cells of the kidney 
(c) Alpha cells of the pancreas
(d) The cells of the rostral adenohypophysis
Ans: (b)

• Option (b) is correct because The juxtaglomerular cells of kidney produce peptide hormone called erythropoietin which stimulates (erythropoiesis). It stimulates the stem cells of the bone marrow to increase red blood cell production.
• Alpha cells of pancreas produce hormone glucagon.
• The cells of rostral adenohypophysis synthesizes hormones of anterior lobe of pituitary.
• The cells of bone marrow are responsible for formation of formed elements.

2020

Q1: Match the following columns and select the correct option.     (NEET 2020)


Ans: (a)
Grave’s disease is due to excess secretion of thyroid hormones (T₃ & T₄). Diabetes mellitus is due to hyposecretion of insulin from beta-cells of pancreas. Diabetes insipidus is due to hyposecretion of ADH from posterior pituitary. Addison’s disease is due to hyposecretion of hormone from adrenal cortex. 

Q2: 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)
Glucagon is associated with hyperglycemia. Insulin acts on hepatocytes and adipocytes and is associated with hypoglycemia. Glucocorticoid stimulates gluconeogenesis, so increase blood sugar level.

2019

Q1: Match the following hormones with their respective disease:

Select the correct option.    (NEET 2019)

Ans: (d)

• Diabetes mellitus is caused due to deficiency of insulin.
• Goite is caused due to deficiency of Iodine which leads to less secretion of thyroxine.
• Addison’s disease is caused due to hyposecretion of corticoids.
• Acromegaly is caused due to hypersecretion of growth hormones after puberty.

2018

Q1: Which of the following is an amino acid derived hormone?    (NEET 2018)
(a) Epinephrine
(b) Ecdysone
(c) Estradiol
(d) Estriol
Ans: (a)
Epinephrine is derived from amino acid tyrosine by the removal of carboxylic group.

2017

Q1: GnRH, a hypothalamic hormone, needed in reproduction, acts on    (NEET 2017)
(a) Anterior pituitary gland and stimulates secretion of LH and FSH
(b) Posterior pituitary gland and stimulates secretion of oxytocin and FSH
(c) Posterior pituitary gland and stimulates secretion of LH and relaxin
(d) Anterior pituitary gland and stimulates secretion of LH and oxytocin.
Ans: (a)
Gonadotropin releasing hormone (GnRH) is secreted by the hypothalamus which stimulates the anterior lobe of pituitary gland to secrete luteinising hormone (LH) and Follicle Stimulating Hormone (FSH).

Q2: A temporary endocrine gland in the human body is    (NEET 2017)
(a) Corpus cardiacum
(b) Corpus luteum
(c) Corpus allatum
(d) Pineal gland.
Ans: (b)
Corpus luteum is the temporary endocrine gland formed in the ovary after ovulation. It release hormones like progesterone, oestrogen etc.

2016

Q1: Graves’ disease is caused due to    (NEET 2016 Phase 2)
(a) Hyposecretion of thyroid gland
(b) Hypersecretion of thyroid gland
(c) Hyposecrction of adrenal gland
(d) Hypersecretion of adrenal gland.
Ans: (b)
Exophthalmic goitre or Graves’ disease is a thyroid enlargement (goitre) in which the thyroid secretes excessive amount of thyroid hormone. It is characterised by exophthalmia (protrusion of eye balls because of fluid accumulation behind them), loss of weight, slightly rise in the body temperature, excitability, rapid heart beat, nervousness and restlessness.

Q2: Name a peptide hormone which acts mainly on hepatocytes, adipocytes and enhances cellular glucose uptake and utilisation.       (NEET 2016 Phase 2)
(a) Insulin
(b) Glucagon
(c) Secretin
(d) Gastrin
Ans: (a)
Insulin is a peptide hormone, secreted by the β cells of the islets of Langerhans in the pancreas, that promotes the uptake of glucose by body cells, particularly in the liver (hepatocytes) and muscles (adipocytes) and thereby controls its concentration in the blood.

Q3: The posterior pituitary gland is not a true endocrine gland because    (NEET 2016 Phase 2)
(a) It is provided with a duct
(b) It only stores and releases hormones
(c) It is under the regulation of hypothalamus
(d) It secretes enzymes.
Ans: (b)
Posterior lobe of pituitary gland does not secrete any hormone. Its hormones are synthesised by the hypothalamus. It only stores and releases these hormones. Hence, it cannot be considered as true gland.

Q4: Changes in GnRH pulse frequency in females is controlled by circulating levels of   (NEET 2016 Phase 1)
(a) Estrogen and progesterone
(b) Estrogen and inhibin
(c) Progesterone only
(d) Progesterone and inhibin
Ans: (a)
At the pituitary, GnRH stimulates the synthesis and secretion of the gonadotropins, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). These processes are controlled by the size and frequency of GnRH pulses, as well as by feedback from progesterone and estrogens. Low-frequency GnRH pulses are required for FSH release, whereas highfrequency GnRH pulses stimulate LH pulses in a one to one manner.

2015

Q1: Which one of the following hormones is not involved in sugar metabolism?    (AIPMT 2015)
(a) Aldosterone
(b) Insulin
(c) Glucagon
(d) Cortisone
Ans: (a)
Aldosterone is produced by adrenal cortex and plays an important role in the regulation of Na⁺ and K⁺ levels in body.

Q2: Which one of the following hormones though synthesised elsewhere is stored and released by the master gland?    (AIPMT 2015) 
(a) Luteinizing hormone
(b) Prolactin
(c) Melanocyte stimulating hormone
(d) Antidiuretic hormone
Ans: (d)
ADH (Antidiuretic hormone) and oxytocin are  produced by hypothalamus and stored in posterior pituitary.

Q3: A chemical signal that has both endocrine and neural roles is?    (AIPMT 2015 Cancelled Paper)
(a) Calcitonin
(b) Epinephrine
(c) Cortisol
(d) Melatonin
Ans: (b)
Epinephrine has two role as a hormone and as a neurotransmitter.

2014

Q1: Identify the hormone with its correct matching of source and function:    (AIPMT 2014)
(a) Oxytocin - posterior pituitary, growth and maintenance of mammary glands.
(b) Melatonin - pineal gland, regulates the normal rhythm of sleepwake cycle.
(c) Progesterone - corpus-luteum, stimulatiuon of growth and activities of female secondary sex orgAns:
(d) Atrial natriuretic factor - ventricular wall increases the blood pressure.
Ans: (b)

• Oxytocin is produced by hypothalamus and generally secreted by posterior pituitary. It stimulates secretion of milk from mammary glands; causes contraction of uterus at the time of child birth.
• Progesterone is secreted by corpus luteum. It stimulates uterus for pregnancy, implantation, formation of placenta and development of mammary glands.
• Atrial natriuretic factor is secreted by atrial wall in response to an increased return of the venous blood. This hormone regulates the blood volume through increased excretion of ions and water.