Development of accessory sex organs

Maturation of accessory sex organs

CHEMICAL COORDINATION AND INTEGRATION MCQs for NEET UG BIOLOGY — Easy, Page 4

91 Easy

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Which of the following is true for the effect of steroid hormone?

View answer and explanation

Correct option: B

Fast and long lasting

The correct answer is B because steroid hormones typically have a slow onset but long-lasting effects due to their mechanism of action involving gene transcription.

Solution approach

Correct Answer + Core Reason: Fast and long lasting. Steroid hormones have a slow onset but long-lasting effects.

Step-by-Step Solution:

Step 1: Recall the mechanism of action of steroid hormones.

Step 2: Steroid hormones are lipid-soluble and can cross the cell membrane. They bind to intracellular receptors, forming a hormone-receptor complex.

Step 3: This complex then enters the nucleus and binds to DNA, affecting gene transcription.

Step 4: This process takes time (slow onset) but results in long-lasting effects due to changes in protein synthesis.

Why other options are wrong:
- Option A: Steroid hormones are not fast-acting.
- Option C: Steroid hormones have long-lasting effects, not short-term effects.
- Option D: Steroid hormones have a slow onset of action.

Key Concepts:
- Steroid hormone mechanism of action
- Gene transcription
- Intracellular receptors

Memory Aids:
- Steroid hormones affect gene transcription, which takes time.

Quick Tips:
- Contrast the mechanism of action of steroid hormones with that of peptide hormones, which bind to cell surface receptors and have faster, shorter-lived effects.

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The abbreviation TSH stands for

View answer and explanation

Correct option: C

Thyroid stimulating hormone

Option C (Thyroid stimulating hormone) is correct because TSH stands for Thyroid Stimulating Hormone, which is secreted by the anterior pituitary gland.

Solution approach

Correct Answer + Core Reason: Thyroid stimulating hormone. TSH stands for Thyroid Stimulating Hormone.

Step-by-Step Solution:

Step 1: Recall the full name of the hormone abbreviated as TSH.

Step 2: TSH stands for Thyroid Stimulating Hormone.

Step 3: Thyroid Stimulating Hormone is secreted by the anterior pituitary gland and stimulates the thyroid gland to produce thyroid hormones (T3 and T4).

Why other options are wrong:
- Option A: Thymine stimulating hormone: Thymine is a component of DNA, not related to this hormone.
- Option B: Thyroxine stimulating hormone: Thyroxine is a thyroid hormone, but TSH stimulates the thyroid gland, not thyroxine directly.
- Option D: None of the above: Option C is correct.

Key Concepts:
- Thyroid Stimulating Hormone (TSH)
- Anterior pituitary gland
- Thyroid gland

Memory Aids:
- TSH = Thyroid Stimulating Hormone

Quick Tips:
- Know the abbreviations of common hormones.

93 Easy

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LH and FSH are collectively called

View answer and explanation

Correct option: D

Gonadotrophins

Option D (Gonadotrophins) is correct because LH (Luteinizing Hormone) and FSH (Follicle-Stimulating Hormone) are hormones that stimulate the gonads and are thus classified as gonadotrophins.

Solution approach

Correct Answer + Core Reason: LH and FSH are collectively called Gonadotrophins because they stimulate the gonads.

Step-by-Step Solution:

Step 1: LH (Luteinizing Hormone) and FSH (Follicle-Stimulating Hormone) are produced by the anterior pituitary gland.

Step 2: These hormones target the gonads (ovaries in females and testes in males).

Step 3: They regulate reproductive functions, including gamete production and hormone secretion.

Step 4: Therefore, they are classified as gonadotrophins.

Why other options are wrong:
- Option A: Oxytocin is a hormone involved in uterine contractions and milk ejection.
- Option B: Somatotrophins are growth hormones.
- Option C: Luteotrophins is not a standard term; LH has luteotrophic effects, but the general term is gonadotrophins.

Key Concepts:
- Gonadotrophins (LH and FSH)
- Anterior pituitary hormones
- Reproductive endocrinology

Memory Aids:
- Gonads = reproductive organs; -trophin = stimulating

Quick Tips:
- Associate LH and FSH with reproductive functions and the term gonadotrophins.

94 Easy

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Which part of brain regulates the body temperature, osmoregulation & ANS-control:-

View answer and explanation

Correct option: C

Hypothalamus

The correct answer is Hypothalamus because it regulates body temperature, osmoregulation, and the autonomic nervous system.

Solution approach

Correct Answer + Core Reason: Hypothalamus. The hypothalamus regulates body temperature, osmoregulation, and ANS control.

Step-by-Step Solution:

Step 1: Recall the functions of the hypothalamus.

Step 2: The hypothalamus is a brain region that plays a crucial role in maintaining homeostasis, including regulating body temperature, osmoregulation (fluid balance), and controlling the autonomic nervous system (ANS).

Step 3: The thalamus primarily relays sensory and motor signals to the cerebral cortex.

Step 4: The pons is involved in regulating sleep, respiration, swallowing, bladder control, hearing, equilibrium, taste, eye movement, facial expressions, facial sensation, and posture.

Step 5: The cerebrum is responsible for higher-level cognitive functions such as thinking, learning, and memory.

Why other options are wrong:
- Option A: Thalamus primarily relays sensory information.
- Option B: Pons is involved in various functions, but not primarily body temperature, osmoregulation, and ANS control.
- Option D: Cerebrum is involved in higher-level cognitive functions.

Key Concepts:
- Hypothalamus function
- Body temperature regulation
- Osmoregulation
- Autonomic nervous system control

Memory Aids:
- Hypothalamus = Homeostasis

Quick Tips:
- Remember the key functions of the hypothalamus in maintaining homeostasis.

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Development of epididymis, vas deference, seminal vesicles, prostate glands and urethra is controlled by

View answer and explanation

Correct option: C

Androgen

Option C (Androgen) is correct because androgens, particularly testosterone, are responsible for the development and maintenance of male secondary sexual characteristics, including the epididymis, vas deferens, seminal vesicles, prostate glands, and urethra.

Solution approach

Correct Answer + Core Reason: Androgen. Androgens, like testosterone, control the development of male reproductive structures.

Step-by-Step Solution:
Step 1: Recall the role of androgens in male sexual development.
Step 2: Androgens, primarily testosterone, are responsible for the development and maintenance of male secondary sexual characteristics.
Step 3: These characteristics include the development of the epididymis, vas deferens, seminal vesicles, prostate glands, and urethra.
Step 4: Therefore, the development of these structures is controlled by androgens.

Why other options are wrong:
- Option A: Estrogen is incorrect because estrogen is the primary female sex hormone.
- Option B: Progesterone is incorrect because progesterone is primarily involved in the female reproductive cycle and pregnancy.
- Option D: Pituitary hormone is incorrect because while pituitary hormones regulate the testes, the direct control of these structures is by androgens.

Key Concepts:
- Androgens (testosterone)
- Male secondary sexual characteristics
- Role of androgens in male sexual development

Memory Aids:
- Androgen = Male

Quick Tips:
- Remember that androgens are the primary hormones responsible for male sexual development.

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Thymus gland releases …… hormone

View answer and explanation

Correct option: C

Thymosins

Option C (Thymosins) is correct because the thymus gland primarily releases thymosins, which are involved in T-lymphocyte development.

Solution approach

Correct Answer + Core Reason: Thymosins. Thymus gland releases thymosins.

Step-by-Step Solution:

Step 1: Recall the hormones secreted by the thymus gland.

Step 2: The thymus gland primarily secretes thymosins.

Step 3: Thymosins play a crucial role in the differentiation and maturation of T-lymphocytes, which are essential for cell-mediated immunity.

Why other options are wrong:
- Option A: ${\mathrm{T}_4}$ : Thyroxine is secreted by the thyroid gland.
- Option B: ${\mathrm{T}_3}$ : Triiodothyronine is secreted by the thyroid gland.
- Option D: TCT: Thyrocalcitonin (Calcitonin) is secreted by the thyroid gland.

Key Concepts:
- Thymus gland
- Thymosins
- T-lymphocytes

Memory Aids:
- Thymus = Thymosins

Quick Tips:
- Know the hormones secreted by different endocrine glands.

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Gigantism and dwarfism are the disease related to

View answer and explanation

Correct option: B

Growth hormone of adenohypophysis

Option B is correct because gigantism and dwarfism are caused by the hypersecretion and hyposecretion, respectively, of growth hormone (GH) from the adenohypophysis.

Solution approach

Correct Answer + Core Reason: Growth hormone of adenohypophysis. Gigantism and dwarfism are caused by abnormal secretion of growth hormone from the anterior pituitary (adenohypophysis).

Step-by-Step Solution:

Step 1: Recall the function of each hormone listed:
- Prolactin: Stimulates milk production.
- Growth hormone: Promotes growth and development.
- Luteinising hormone: Stimulates ovulation and testosterone production.
- Thyroid stimulating hormone: Stimulates thyroid hormone production.

Step 2: Identify the hormone related to gigantism and dwarfism: Gigantism (excessive growth) and dwarfism (stunted growth) are caused by abnormal levels of growth hormone.

Why other options are wrong:
- Option A: Prolactin is related to milk production, not growth disorders like gigantism and dwarfism.
- Option C: Luteinising hormone is related to reproductive functions, not growth disorders like gigantism and dwarfism.
- Option D: Thyroid stimulating hormone is related to thyroid hormone production, which affects metabolism, but not directly gigantism and dwarfism.

Key Concepts:
- Growth hormone and its function
- Gigantism and dwarfism
- Adenohypophysis (anterior pituitary)

Memory Aids:
- GH = Growth Hormone

Quick Tips:
- Remember that growth hormone is produced by the anterior pituitary and affects overall body growth.

98 Easy

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Blood calcium level is a resultant of how much dietary calcium
is absorbed, how much calcium is lost in the urine, how much
bone dissolves releasing calcium into blood and how much
calcium from blood enters tissues. A number of factor play an
important role in these processes. Mark the one which has no
role.

View answer and explanation

Correct option: D

Thymosin

Option D (Thymosin) is correct because thymosin is a hormone produced by the thymus gland involved in T-cell development and does not directly regulate blood calcium levels.

Solution approach

Correct Answer + Core Reason: Thymosin. Thymosin is involved in T-cell development and does not directly regulate blood calcium levels.

Step-by-Step Solution:

Step 1: Recall the factors that regulate blood calcium levels.

Step 2: Vitamin D promotes calcium absorption from the diet.

Step 3: Parathyroid hormone (PTH) increases blood calcium levels by stimulating bone resorption and increasing calcium reabsorption in the kidneys.

Step 4: Thyrocalcitonin (calcitonin) decreases blood calcium levels by inhibiting bone resorption.

Step 5: Thymosin is produced by the thymus and is involved in T-cell development, not calcium regulation.

Step 6: Therefore, thymosin has no direct role in blood calcium level regulation.

Why other options are wrong:
- Option A: Vitamin D plays a crucial role in calcium absorption from the diet.
- Option B: Parathyroid hormone is a key regulator of blood calcium levels.
- Option C: Thyrocalcitonin (calcitonin) lowers blood calcium levels.
- Option D: Thymosin is involved in T-cell development, not calcium regulation.

Key Concepts:
- Endocrine System
- Blood Calcium Regulation
- Vitamin D
- Parathyroid Hormone (PTH)
- Calcitonin
- Thymosin

Memory Aids:
- PTH = Pulls calcium from bone.

Quick Tips:
- Know the hormones and vitamins involved in calcium homeostasis.

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The posterior pituitary is under the

View answer and explanation

Correct option: B

Direct neural regulation of the hypothalamus

Option B is correct because the posterior pituitary (neurohypophysis) is directly regulated by neural signals from the hypothalamus.

Solution approach

Correct Answer + Core Reason: B. Direct neural regulation of the hypothalamus. The posterior pituitary is a direct extension of the hypothalamus.

Step-by-Step Solution:

Step 1: The posterior pituitary (neurohypophysis) stores and releases hormones that are produced by the hypothalamus.

Step 2: The hypothalamus directly controls the release of these hormones via neural signals (axons).

Step 3: The hormones are synthesized in the hypothalamus and transported down axons to the posterior pituitary for storage and release.

Why other options are wrong:
- Option A: The adenohypophysis (anterior pituitary) is regulated by releasing and inhibiting hormones from the hypothalamus, not direct neural regulation.
- Option C: The adenohypophysis is regulated by hormones, not direct axonal connections.
- Option D: The neurohypophysis is regulated by the hypothalamus, not by its own axonal regulation.

Key Concepts:
- Hypothalamus-pituitary axis
- Neurohypophysis (posterior pituitary) function
- Adenohypophysis (anterior pituitary) function

Memory Aids:
- Posterior = neural (direct neural connection to hypothalamus)
- Anterior = hormonal (hormonal regulation from hypothalamus)

Quick Tips:
- Remember the difference between the anterior and posterior pituitary regulation.

100 Easy

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Select the odd one w.r.t functions of the thyroid hormones.

View answer and explanation

Correct option: D

Increase the blood

Ca^{++}

levels

Option D (Increase the blood

Ca^{++}

levels) is correct because increasing blood calcium levels is a function of parathyroid hormone, not thyroid hormones.

Solution approach

Correct Answer + Core Reason: Increase the blood $Ca^{++}$ levels. This function is associated with parathyroid hormone, not thyroid hormones.

Step-by-Step Solution:

Step 1: Analyze the functions of thyroid hormones:
- Maintenance of water and electrolyte balance: Thyroid hormones contribute to this.
- Support the process of red blood cell formation: Thyroid hormones play a supporting role.
- Control the metabolism of carbohydrates, proteins, and fats: Thyroid hormones are crucial for metabolic regulation.
- Increase the blood $Ca^{++}$ levels: This is the function of parathyroid hormone (PTH), not thyroid hormones. Calcitonin, secreted by the thyroid gland, decreases blood calcium levels.

Step 2: Identify the odd one out: The function that does not belong to thyroid hormones is increasing blood calcium levels.

Why other options are wrong:
- Option A: Maintenance of water and electrolyte balance is a function of thyroid hormones.
- Option B: Supporting the process of red blood cell formation is a function of thyroid hormones.
- Option C: Controlling the metabolism of carbohydrates, proteins, and fats is a function of thyroid hormones.

Key Concepts:
- Thyroid hormones
- Parathyroid hormone (PTH)
- Calcitonin
- Calcium regulation

Memory Aids:
- PTH increases calcium; Calcitonin decreases calcium.

Quick Tips:
- Remember the roles of PTH and calcitonin in calcium homeostasis.

101 Easy

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Injury to the hypothalamus would most likely disrupt the

View answer and explanation

Correct option: D

Regulation of body temperature

The correct answer is D (Regulation of body temperature) because the hypothalamus plays a crucial role in thermoregulation.

Solution approach

Correct Answer + Core Reason: Regulation of body temperature. The hypothalamus is a key regulator of body temperature.

Step-by-Step Solution:

Step 1: Recall the functions of the hypothalamus.

Step 2: The hypothalamus is involved in various homeostatic functions, including temperature regulation, hunger, thirst, and sleep-wake cycles.

Step 3: Injury to the hypothalamus would most likely disrupt these functions, with temperature regulation being a primary one.

Why other options are wrong:
- Option A: Short-term memory is primarily associated with the hippocampus and other brain regions.
- Option B: Coordination during locomotion is primarily associated with the cerebellum.
- Option C: Executive functions such as decision-making are primarily associated with the prefrontal cortex.

Key Concepts:
- Hypothalamus function
- Thermoregulation

Memory Aids:
- Hypothalamus: homeostasis (temperature, hunger, thirst)

Quick Tips:
- Remember the key functions associated with different brain regions.

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Who is known as ‘father of Endocrinology’?

View answer and explanation

Correct option: D

Thomas Addison

Option D (Thomas Addison) is correct because Thomas Addison is known as the \'father of Endocrinology\'.

Solution approach

Correct Answer + Core Reason: Thomas Addison. Thomas Addison is known as the \'father of Endocrinology\'.

Step-by-Step Solution:

Step 1: Recall the history of endocrinology.

Step 2: Thomas Addison made significant contributions to the understanding of adrenal gland disorders, leading to his recognition as the \"father of endocrinology.\"

Why other options are wrong:
- Option A: R H Whittaker: Known for his five-kingdom classification.
- Option B: Pasteur: Known for his work on pasteurization and germ theory.
- Option C: Einthoven: Known for inventing the electrocardiogram (ECG).

Key Concepts:
- History of endocrinology
- Thomas Addison

Memory Aids:
- Addison's disease = adrenal insufficiency.

Quick Tips:
- Know the key figures in the history of science.

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Incorrect match w.r.t hormone and its chemical nature is

View answer and explanation

Correct option: C

Glucagon - Steroidal

Option C (Glucagon - Steroidal) is correct because glucagon is a peptide hormone, not a steroidal hormone.

Solution approach

Correct Answer + Core Reason: Glucagon - Steroidal. Glucagon is a peptide hormone, not a steroid.

Step-by-Step Solution:

Step 1: Identify the chemical nature of each hormone.

Step 2: Cortisol is a steroid hormone produced by the adrenal cortex.

Step 3: Thyroxine is an iodothyronine, a derivative of tyrosine.

Step 4: Glucagon is a peptide hormone produced by the pancreas.

Step 5: Thyrocalcitonin (Calcitonin) is a proteinaceous hormone produced by the thyroid gland.

Why other options are wrong:
- Option A: Cortisol is indeed a steroidal hormone, so this match is correct.
- Option B: Thyroxine is an iodothyronine, a thyroid hormone containing iodine, so this match is correct.
- Option D: Thyrocalcitonin (Calcitonin) is a proteinaceous hormone produced by the thyroid gland, so this match is correct.

Key Concepts:
- Hormones and their chemical nature (steroid, peptide, etc.)

Memory Aids:
- Steroid hormones are often derived from cholesterol.

Quick Tips:
- Know the chemical classification of common hormones.

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Glucocorticoids are the corticoids which

View answer and explanation

Correct option: C

Are involved in glucose metabolism

Option C (Are involved in glucose metabolism) is correct because glucocorticoids primarily regulate glucose levels in the body through processes like gluconeogenesis.

Solution approach

Correct Answer + Core Reason: Are involved in glucose metabolism. Glucocorticoids primarily regulate glucose levels.

Step-by-Step Solution:

Step 1: Recall the function of glucocorticoids: Glucocorticoids are steroid hormones that primarily affect glucose metabolism.

Step 2: Consider the options: While glucocorticoids can have some effects on protein and fat metabolism, their primary role is in glucose regulation.

Step 3: Identify the primary function: Glucocorticoids stimulate gluconeogenesis, increase blood glucose levels, and affect glucose metabolism.

Why other options are wrong:
- Option A: While glucocorticoids can influence protein metabolism, it's not their primary function.
- Option B: While glucocorticoids can influence fat metabolism, it's not their primary function.
- Option D: While glucocorticoids have effects on all three, glucose metabolism is their primary role.

Key Concepts:
- Glucocorticoids
- Glucose metabolism
- Gluconeogenesis

Memory Aids:
- Gluco-corticoids = glucose.

Quick Tips:
- Remember the primary function of glucocorticoids in glucose regulation.

105 Easy

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Which of the following are heterocine glands;  I. Thyroid,  II. Parathyroid,  III. Ovary,  IV. Testis,  V. Pituitary,  VI. Pancreas.  Choose the correct option

View answer and explanation

Correct option: B

III, IV and VI

Option B (III, IV and VI) is correct because ovaries, testes, and the pancreas have both endocrine and exocrine functions.

Solution approach

Correct Answer + Core Reason: III, IV and VI. Ovaries, testes, and pancreas have both endocrine and exocrine functions.

Step-by-Step Solution:

Step 1: Define heterocrine glands. Heterocrine glands, also known as mixed glands, have both endocrine (hormone-secreting) and exocrine (duct-secreting) functions.

Step 2: Analyze each gland: \nI. Thyroid: Primarily endocrine.\nII. Parathyroid: Primarily endocrine.\nIII. Ovary: Heterocrine (endocrine: estrogen, progesterone; exocrine: egg production).\nIV. Testis: Heterocrine (endocrine: testosterone; exocrine: sperm production).\nV. Pituitary: Primarily endocrine.\nVI. Pancreas: Heterocrine (endocrine: insulin, glucagon; exocrine: digestive enzymes).

Step 3: Identify the heterocrine glands from the list: Ovary, Testis, and Pancreas.

Why other options are wrong:
- Option A: Incorrect because thyroid and parathyroid are primarily endocrine.
- Option C: Incorrect because thyroid and pituitary are primarily endocrine.
- Option D: Incorrect because thyroid and pituitary are primarily endocrine.

Key Concepts:
- Heterocrine glands
- Endocrine and exocrine functions

Memory Aids:
- Remember that ovaries, testes, and the pancreas have dual roles.

Quick Tips:
- Differentiate between endocrine, exocrine, and heterocrine glands.

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Hormones which interact with the membrane-bound receptors normally do not enter the target
cell but generate second messengers. These second messengers are referred as

View answer and explanation

Correct option: D

All the above

Option D (All the above) is correct because cAMP, calcium ions, and inositol 3-phosphate are all well-known second messengers in hormone signaling.

Solution approach

Correct Answer + Core Reason: All the above. cAMP, calcium ion, and inositol 3-phosphate are all common second messengers.

Step-by-Step Solution:

Step 1: Hormones that bind to membrane-bound receptors often do not enter the cell directly.

Step 2: Instead, they trigger the production of intracellular signaling molecules called second messengers.

Step 3: Common second messengers include cAMP, calcium ions (Ca2+), and inositol 3-phosphate (IP3).

Why other options are wrong:
- Option A: While Calcium ion and inositol 3-phosphate are second messengers, the answer is incomplete.
- Option B: While Inositol 3-phosphate and cAMP are second messengers, the answer is incomplete.
- Option C: While cAMP and calcium ion are second messengers, the answer is incomplete.

Key Concepts:
- Second messengers
- Membrane-bound receptors
- Signal transduction

Memory Aids:
- Think of second messengers as relaying the hormone's message inside the cell.

Quick Tips:
- Remember the common second messengers: cAMP, calcium ions, and IP3.

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CCK acts on

View answer and explanation

Correct option: C

Both (a) and (b)

Option C (Both (a) and (b)) is correct because CCK stimulates both the pancreas to release digestive enzymes and the gallbladder to contract and release bile.

Solution approach

Correct Answer + Core Reason: Both (a) and (b). CCK acts on both the pancreas and the gall bladder to aid in digestion.

Step-by-Step Solution:

Step 1: CCK (Cholecystokinin) is a peptide hormone secreted by the duodenum in response to the presence of fats and proteins in the chyme.

Step 2: CCK stimulates the pancreas to release digestive enzymes (such as amylase, lipase, and protease) into the small intestine to aid in the digestion of fats and proteins.

Step 3: CCK also stimulates the gallbladder to contract and release bile into the small intestine to emulsify fats, making them easier to digest and absorb.

Why other options are wrong:
- Option A: While CCK acts on the pancreas, it also acts on the gallbladder, making this option incomplete.
- Option B: While CCK acts on the gallbladder, it also acts on the pancreas, making this option incomplete.
- Option D: CCK does not directly act on the liver. The liver produces bile, which is then stored in the gallbladder, and CCK stimulates the gallbladder to release the bile.

Key Concepts:
- CCK (Cholecystokinin)
- Pancreas
- Gallbladder
- Digestive enzymes
- Bile

Memory Aids:
- CCK: \"Chole-cysto-kinin\" - think gallbladder and enzyme release.

Quick Tips:
- Understand the roles of CCK in digestion.

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Which of the following are identical?

View answer and explanation

Correct option: D

Vasopressin and ADH

Option D (Vasopressin and ADH) is correct because Vasopressin is another name for ADH (Antidiuretic Hormone).

Solution approach

Correct Answer + Core Reason: Vasopressin and ADH. Vasopressin is another name for Antidiuretic Hormone (ADH).

Step-by-Step Solution:

Step 1: Recall the different names for hormones.

Step 2: Vasopressin and ADH are the same hormone, produced by the hypothalamus and released by the posterior pituitary.

Why other options are wrong:
- Option A: ACTH and adrenaline: ACTH stimulates the adrenal cortex; adrenaline is produced by the adrenal medulla.
- Option B: HCG and progesterone: HCG stimulates progesterone production, but they are different hormones.
- Option C: Calcitonin and oxytocin: Calcitonin lowers blood calcium; oxytocin stimulates uterine contractions and milk ejection.

Key Concepts:
- Hormone names and functions

Memory Aids:
- ADH = Anti-Diuretic Hormone = Vasopressin.

Quick Tips:
- Be aware of different names for the same hormone.

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Which of the following statements regarding glucagon is false?

View answer and explanation

Correct option: C

It decreases blood sugar level

Option C (It decreases blood sugar level) is correct because glucagon increases, not decreases, blood sugar level.

Solution approach

Correct Answer + Core Reason: It decreases blood sugar level. This statement is false because glucagon is a hyperglycemic hormone, meaning it increases blood sugar levels.

Step-by-Step Solution:

Step 1: Understand the function of glucagon.

Step 2: Glucagon is secreted by alpha cells of the pancreas and acts antagonistically to insulin.

Step 3: Glucagon increases blood sugar levels by promoting glycogenolysis and gluconeogenesis.

Step 4: Therefore, the statement that it decreases blood sugar level is false.

Why other options are wrong:
- Option A: Glucagon is indeed secreted by alpha cells of Langerhans.
- Option B: Glucagon does act antagonistically to insulin, which lowers blood sugar.
- Option D: The pancreas is a heterocrine gland, having both endocrine and exocrine functions, and is responsible for glucagon secretion.

Key Concepts:
- Glucagon function
- Alpha cells of the pancreas
- Heterocrine glands

Memory Aids:
- Glucagon = Glucose up.

Quick Tips:
- Remember the opposing roles of insulin and glucagon.

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Parathormone is responsible for:-

View answer and explanation

Correct option: D

Regulation of

C{a^{ + 2}}

level in blood

Option D (Regulation of

C{a^{ + 2}}

level in blood) is correct because parathormone's primary function is to increase blood calcium levels.

Solution approach

Correct Answer + Core Reason: Parathormone is responsible for regulation of $Ca^{+2}$ level in blood.

Step-by-Step Solution:

Step 1: Parathormone (PTH) is secreted by the parathyroid glands.

Step 2: PTH increases blood calcium levels by:
- Stimulating osteoclasts to break down bone and release calcium into the blood.
- Increasing calcium reabsorption in the kidneys, preventing its loss in urine.
- Indirectly increasing calcium absorption from the digested food in the intestine (by activating Vitamin D).

Step 3: These actions collectively raise the concentration of $Ca^{+2}$ in the blood.

Why other options are wrong:
- Option A: While PTH influences electrolyte balance indirectly through its action on the kidneys, its primary role is calcium regulation, not overall water and electrolyte maintenance.
- Option B: PTH actually promotes the *de*mineralization (breakdown) of bone to release calcium, not mineralization (building up) of bone.
- Option C: PTH *reduces* the excretion of $Ca^{+2}$ from the nephron by increasing its reabsorption back into the blood.

Key Concepts:
- Parathormone (PTH) function
- Calcium homeostasis
- Bone remodeling
- Kidney function in calcium regulation

Memory Aids:
- PTH: ParaThyroid Hormone - Think "Para" as in "parallel" with increasing calcium in blood. It works to *raise* calcium levels.

Quick Tips:
- Remember that PTH's main job is to *increase* blood calcium. Think about how it achieves this through bone, kidneys, and intestines.

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Hyposecretion of growth hormone causes

View answer and explanation

Correct option: A

Dwarfism

Option A is correct because hyposecretion (undersecretion) of growth hormone during childhood causes dwarfism, characterized by stunted growth.

Solution approach

Correct Answer + Core Reason: Dwarfism. Hyposecretion of growth hormone causes dwarfism.

Step-by-Step Solution:

Step 1: Recall the function of growth hormone: Promotes growth and development.

Step 2: Understand the effects of hyposecretion of growth hormone: Hyposecretion leads to stunted growth, resulting in dwarfism.

Why other options are wrong:
- Option B: Cretinism is caused by hypothyroidism in children.
- Option C: Myxoedema is caused by hypothyroidism in adults.
- Option D: Acromegaly is caused by hypersecretion of growth hormone in adults.

Key Concepts:
- Growth hormone and its function
- Dwarfism
- Cretinism
- Myxoedema
- Acromegaly

Memory Aids:
- Hypo = Low
- Hyper = High

Quick Tips:
- Remember the difference between hyposecretion and hypersecretion and their effects on growth hormone levels.

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Select the odd one w.r.t. functions of PTH.

View answer and explanation

Correct option: B

Stimulates mineralisation of bones

The correct answer is B (Stimulates mineralisation of bones) because PTH actually stimulates bone resorption (breakdown), which releases calcium into the blood, not mineralisation.

Solution approach

Correct Answer + Core Reason: Stimulates mineralisation of bones. PTH stimulates bone resorption, not mineralisation.

Step-by-Step Solution:

Step 1: Recall the function of PTH: Parathyroid hormone (PTH) is secreted by the parathyroid glands in response to low blood calcium levels.

Step 2: Understand the effects of PTH on calcium levels: PTH increases blood calcium levels by:
- Stimulating bone resorption (breakdown of bone) to release calcium into the blood.
- Increasing calcium absorption from digested food in the intestines (indirectly through vitamin D activation).
- Increasing calcium reabsorption by the renal tubules in the kidneys.

Step 3: Identify the incorrect function of PTH: PTH stimulates bone resorption, not mineralisation. Mineralisation is the process of depositing minerals (like calcium) into the bone matrix, which is the opposite of what PTH does.

Why other options are wrong:
- Option A: Increases levels of ${Ca}^{2+}$ in blood is a correct function of PTH.
- Option C: Increases ${Ca}^{2+}$ absorption from digested food is a correct function of PTH (indirectly through vitamin D).
- Option D: Stimulates ${Ca}^{2+}$ reabsorption by renal tubules is a correct function of PTH.

Key Concepts:
- Parathyroid hormone (PTH)
- Calcium regulation
- Bone resorption
- Bone mineralisation
- Renal reabsorption

Memory Aids:
- Think of "PTH" as "Pulling calcium from the bones" to increase blood calcium levels.

Quick Tips:
- Remember that PTH increases blood calcium levels by stimulating bone resorption, increasing calcium absorption from the gut, and increasing calcium reabsorption by the kidneys.

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Hyposecretion of which of the following can cause diabetes insipidus?

View answer and explanation

Correct option: D

ADH

Option D is correct because diabetes insipidus is caused by the hyposecretion of ADH (antidiuretic hormone), which leads to the inability of the kidneys to reabsorb water.

Solution approach

Correct Answer + Core Reason: ADH. Hyposecretion of ADH causes diabetes insipidus.

Step-by-Step Solution:

Step 1: Recall the function of each hormone listed:
- Insulin: Regulates blood glucose levels.
- Thyroxine: Regulates metabolism.
- Glucagon: Increases blood glucose levels.
- ADH: Promotes water reabsorption in the kidneys.

Step 2: Identify the hormone related to diabetes insipidus: Diabetes insipidus is characterized by excessive thirst and urination of dilute urine, which is due to a deficiency in ADH.

Why other options are wrong:
- Option A: Insulin deficiency causes diabetes mellitus, not diabetes insipidus.
- Option B: Thyroxine deficiency causes hypothyroidism, not diabetes insipidus.
- Option C: Glucagon deficiency can cause hypoglycemia, not diabetes insipidus.

Key Concepts:
- Diabetes insipidus and its causes
- ADH (antidiuretic hormone) and its function
- Insulin and its function
- Thyroxine and its function
- Glucagon and its function

Memory Aids:
- ADH = Anti-Diuretic Hormone (prevents diuresis/urine production)

Quick Tips:
- Differentiate between diabetes mellitus (insulin) and diabetes insipidus (ADH).

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Assertion: Catecholamine increases the concentration of glucose in blood.

Reason: Catecholamine stimulates glycogenolysis.

View answer and explanation

Correct option: A

If both the assertion and the reason are true and the reason is a correct explanation of the assertion

Option A (If both the assertion and the reason are true and the reason is a correct explanation of the assertion) is correct because catecholamines increase blood glucose by stimulating glycogenolysis.

Solution approach

Correct Answer + Core Reason: If both the assertion and the reason are true and the reason is a correct explanation of the assertion. Catecholamines increase blood glucose concentration by stimulating glycogenolysis.

Step-by-Step Solution:

Step 1: Analyze the assertion: Catecholamine increases the concentration of glucose in blood.

Step 2: Catecholamines (epinephrine and norepinephrine) are released during stress and increase blood glucose levels. Therefore, the assertion is true.

Step 3: Analyze the reason: Catecholamine stimulates glycogenolysis.

Step 4: Glycogenolysis is the breakdown of glycogen into glucose. Catecholamines stimulate glycogenolysis in the liver, releasing glucose into the bloodstream. Therefore, the reason is true.

Step 5: Determine if the reason explains the assertion.

Step 6: The reason (catecholamines stimulate glycogenolysis) directly explains why catecholamines increase blood glucose concentration. Therefore, the reason is a correct explanation of the assertion.

Final Answer: If both the assertion and the reason are true and the reason is a correct explanation of the assertion.

Why other options are wrong:
- Option A (If both the assertion and the reason are true and the reason is a correct explanation of the assertion): This is the correct answer as explained above.
- Option B (If both the assertion and reason are true but the reason is not a correct explanation of the assertion): The reason correctly explains the assertion.
- Option C (If the assertion is true but the reason is false): The reason is also true.
- Option D (If both the assertion and reason are false): Both the assertion and the reason are true.

Key Concepts:
- Catecholamine effects on blood glucose
- Glycogenolysis

Memory Aids:
- Catecholamines: "Fight or Flight" response (increases energy availability through glucose release)

Quick Tips:
- Understand the mechanisms by which hormones regulate blood glucose levels.

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Among various ions encountered in living cells, the ions most commonly used in cellular signalling as second messenger are

View answer and explanation

Correct option: D

{Ca}^{2+}

Option D (

{Ca}^{2+}

) is correct because calcium ions are widely used as secondary messengers in various cellular signaling pathways.

Solution approach

Correct Answer + Core Reason: ${Ca}^{2+}$ . Calcium ions are commonly used as secondary messengers.

Step-by-Step Solution:

Step 1: Recall the role of ions in cellular signaling.

Step 2: Identify the ions commonly used as secondary messengers.

Step 3: Remember that ${Ca}^{2+}$ is a key secondary messenger involved in various cellular processes.

Step 4: Conclude that ${Ca}^{2+}$ is the most commonly used ion in cellular signaling as a second messenger.

Why other options are wrong:
- Option A: ${Fe}^{2+}$ is important for enzymes and oxygen transport but not a common secondary messenger.
- Option B: ${K}^{+}$ is important for maintaining membrane potential but not a common secondary messenger.
- Option C: ${Na}^{+}$ is important for nerve impulse transmission but not a common secondary messenger.

Key Concepts:
- Secondary messengers
- Calcium ions
- Signal transduction

Memory Aids:
- Calcium: Key secondary messenger

Quick Tips:
- Remember the role of calcium in cellular signaling.

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Hormone responsible for the control of the development of secondary sexual characters in females is

View answer and explanation

Correct option: B

Oestrogen

Option B (Oestrogen) is correct because oestrogen is the primary hormone responsible for the development of secondary sexual characteristics in females.

Solution approach

Correct Answer + Core Reason: Oestrogen. Oestrogen is responsible for the development of secondary sexual characteristics in females.

Step-by-Step Solution:

Step 1: Identify the hormones involved in female sexual development.

Step 2: Oestrogen is a group of steroid hormones primarily produced by the ovaries.

Step 3: Oestrogen promotes the development of secondary sexual characteristics in females, such as breast development, widening of the hips, and changes in body fat distribution.

Step 4: Androgens are primarily male sex hormones, progesterone is involved in the menstrual cycle and pregnancy, and oxytocin is involved in uterine contractions and milk ejection.

Why other options are wrong:
- Option A: Androgens are primarily male sex hormones and are responsible for the development of secondary sexual characteristics in males.
- Option C: Progesterone is primarily involved in the menstrual cycle and pregnancy, not the development of secondary sexual characteristics.
- Option D: Oxytocin is involved in uterine contractions and milk ejection, not the development of secondary sexual characteristics.

Key Concepts:
- Oestrogen function
- Secondary sexual characteristics
- Female sexual development

Memory Aids:
- "Oestrogen" sounds like "Esther-gen", think of Esther as a typical female, reminding you of its role in female development.

Quick Tips:
- Remember that oestrogen is the primary hormone responsible for the development of female secondary sexual characteristics.

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Diurnal rhythm of our body is maintained by

View answer and explanation

Correct option: B

Pineal gland

Option B (Pineal gland) is correct because the pineal gland secretes melatonin, which regulates the diurnal rhythm of the body.

Solution approach

Correct Answer + Core Reason: Pineal gland. Melatonin regulates the diurnal rhythm.

Step-by-Step Solution:

Step 1: Understand the concept of diurnal rhythm (sleep-wake cycle).

Step 2: Identify the gland responsible for regulating the diurnal rhythm.

Step 3: The pineal gland secretes melatonin, which influences sleep-wake cycles and other circadian rhythms.

Why other options are wrong:
- Option A: Thyroid gland: The thyroid gland regulates metabolism.
- Option C: Pituitary gland: The pituitary gland controls various other endocrine glands.
- Option D: Hypothalamus: The hypothalamus regulates body temperature, hunger, and thirst, but the pineal gland is more directly involved in diurnal rhythms.

Key Concepts:
- Diurnal rhythm
- Pineal gland
- Melatonin

Memory Aids:
- Pineal = Sleep

Quick Tips:
- Remember that melatonin is associated with sleep and darkness.

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Androgens regulates

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because androgens, like testosterone, regulate the development, maturation, and function of male accessory sex organs and promote muscular growth.

Solution approach

Correct Answer + Core Reason: All of the above. Androgens have multiple functions related to male sexual characteristics and development.

Step-by-Step Solution:
Step 1: Define androgens and their primary function.
Step 2: Recall that androgens (e.g., testosterone) are male sex hormones.
Step 3: Consider the effects of androgens on accessory sex organs, muscular growth, and maturation.

Why other options are wrong:
- Option A: While androgens do regulate the development of accessory sex organs, this is not the only function.
- Option B: While androgens do promote muscular growth, this is not the only function.
- Option C: While androgens do regulate the maturation of accessory sex organs, this is not the only function.

Key Concepts:
- Androgens
- Testosterone
- Male reproductive system

Memory Aids:
- Androgens = Male characteristics

Quick Tips:
- Remember the broad range of effects androgens have on male physiology.

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The hyposecretion of which hormone leads to loss of sodium and water through urine, low blood pressure and hypotension?

View answer and explanation

Correct option: B

Hormones of adrenal cortex

Option B (Hormones of adrenal cortex) is correct because aldosterone, a hormone of the adrenal cortex, regulates sodium and water balance.

Solution approach

Correct Answer + Core Reason: Hormones of adrenal cortex. Hyposecretion of aldosterone, a hormone of the adrenal cortex, leads to loss of sodium and water, low blood pressure, and hypotension.

Step-by-Step Solution:

Step 1: Identify the hormone responsible for sodium and water balance.

Step 2: Aldosterone, a mineralocorticoid produced by the adrenal cortex, regulates sodium reabsorption in the kidneys. When aldosterone secretion is low (hyposecretion), sodium and water are not properly reabsorbed, leading to their loss in urine.

Step 3: Loss of sodium and water leads to decreased blood volume, resulting in low blood pressure and hypotension.

Step 4: Thyrotropic hormones regulate thyroid gland function.

Step 5: Hormones of the adrenal medulla (epinephrine and norepinephrine) primarily regulate the "fight or flight" response.

Step 6: Luteotrophic hormones (e.g., prolactin) are involved in lactation and other reproductive functions.

Final Answer: Hormones of adrenal cortex.

Why other options are wrong:
- Option A (Thyrotropic hormones): These hormones regulate the thyroid gland, not sodium and water balance.
- Option B (Hormones of adrenal cortex): This is the correct answer as explained above.
- Option C (Hormones of adrenal medulla): These hormones regulate the "fight or flight" response, not sodium and water balance primarily.
- Option D (Luteotrophic hormones): These hormones are involved in lactation and other reproductive functions, not sodium and water balance.

Key Concepts:
- Aldosterone function (sodium and water balance)
- Adrenal cortex hormones
- Adrenal medulla hormones
- Thyrotropic hormones
- Luteotrophic hormones

Memory Aids:
- Aldosterone: "Salt-retaining" hormone

Quick Tips:
- Remember the primary functions of hormones from different glands.

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Which of the following is the function of adrenaline?

View answer and explanation

Correct option: B

Increase heart rate and blood pressure

Option B is correct because adrenaline (epinephrine) increases heart rate and blood pressure as part of the "fight or flight" response.

Solution approach

Correct Answer + Core Reason: B. Increase heart rate and blood pressure. Adrenaline increases heart rate and blood pressure.

Step-by-Step Solution:

Step 1: Recall the effects of adrenaline (epinephrine) on the body.

Step 2: Adrenaline is released during stress or emergency situations and causes increased heart rate, blood pressure, and bronchodilation.

Step 3: This prepares the body for "fight or flight".

Why other options are wrong:
- Option A: Adrenaline does not directly help in gastric juice secretion.
- Option C: Adrenaline does not directly increase blood calcium levels.
- Option D: Adrenaline does not help in milk secretion; prolactin and oxytocin are involved in milk production and ejection, respectively.

Key Concepts:
- Adrenaline (epinephrine) function
- "Fight or flight" response
- Cardiovascular effects of adrenaline

Memory Aids:
- Adrenaline: Increases heart rate and blood pressure during emergencies.

Quick Tips:
- Remember the physiological effects of adrenaline during stress.

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