CHEMICAL COORDINATION AND INTEGRATION MCQs for NEET UG BIOLOGY — Easy, Page 3

61 Easy

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A pair of testis are present in the …… of humans (male)

View answer and explanation

Correct option: B

Scrotal sac

Option B (Scrotal sac) is correct because the testes are located within the scrotal sac in males.

Solution approach

Correct Answer + Core Reason: Scrotal sac. The testes are located within the scrotal sac.

Step-by-Step Solution:
Step 1: Recall the location of the testes in males.
Step 2: The testes are located outside the abdominal cavity within the scrotal sac.
Step 3: The scrotal sac helps regulate the temperature of the testes for optimal sperm production.
Step 4: Therefore, the testes are present in the scrotal sac.

Why other options are wrong:
- Option A: Peritoneal cavity is incorrect because the testes are located outside the peritoneal cavity.
- Option C: Inguinal canal is incorrect because the testes descend through the inguinal canal during development, but they are not located within it in adults.
- Option D: Isthmus is incorrect because the isthmus is a narrow passage or constriction, not related to the location of the testes.

Key Concepts:
- Location of the testes
- Scrotal sac
- Temperature regulation of the testes

Memory Aids:
- Scrotum = Testes

Quick Tips:
- Remember that the testes are located outside the abdominal cavity in the scrotal sac.

62 Easy

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Largest endocrine gland is

View answer and explanation

Correct option: C

Thyroid

Option C (Thyroid) is correct because the thyroid gland is the largest endocrine gland in the body.

Solution approach

Correct Answer + Core Reason: Thyroid. The thyroid gland is the largest endocrine gland.

Step-by-Step Solution:

Step 1: Recall the relative sizes of the major endocrine glands.

Step 2: The thyroid gland is located in the neck and is the largest endocrine gland.

Step 3: The pituitary gland is located in the brain and is relatively small.

Step 4: The adrenal glands are located on top of the kidneys and are smaller than the thyroid gland.

Step 5: The pineal gland is located in the brain and is very small.

Why other options are wrong:
- Option A: Pituitary gland is small in size.
- Option B: Adrenal glands are smaller than the thyroid gland.
- Option D: Pineal gland is very small in size.

Key Concepts:
- Endocrine gland size

Memory Aids:
- Thyroid = Largest

Quick Tips:
- Remember the relative sizes of the major endocrine glands.

63 Easy

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Adrenal gland is present at the

View answer and explanation

Correct option: D

Anterior side of each kidney

Option D is correct because the adrenal glands are located on the anterior (superior) side of each kidney.

Solution approach

Correct Answer + Core Reason: D. Anterior side of each kidney. Adrenal glands are located on the anterior side of each kidney.

Step-by-Step Solution:

Step 1: Recall the anatomical location of the adrenal glands.

Step 2: The adrenal glands are located superior (anterior) to each kidney.

Why other options are wrong:
- Option A: The adrenal glands are not located on the lateral side of the kidneys.
- Option B: The adrenal glands are not located on the dorsal side of the kidneys.
- Option C: The adrenal glands are not located on the posterior side of the kidneys.

Key Concepts:
- Adrenal gland anatomy
- Kidney anatomy

Memory Aids:
- Adrenal: Above the kidneys

Quick Tips:
- Visualize the location of the adrenal glands in relation to the kidneys.

64 Easy

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Read the following statements:
Assertion (A): Acromegaly may lead to serious complications, and premature death if unchecked.
Reason (R): ACTH stimulates the synthesis and secretion of steroid hormones called glucocorticoids from the adrenal cortex.

View answer and explanation

Correct option: B

A and R are true and R is not the correct explanation of A.

Option B (A and R are true and R is not the correct explanation of A) is correct because both the assertion and reason are true statements, but the reason does not explain the assertion. Acromegaly is caused by excess growth hormone, not ACTH.

Solution approach

Correct Answer + Core Reason: A and R are true and R is not the correct explanation of A. Acromegaly is caused by excess growth hormone, while ACTH stimulates glucocorticoid release.

Step-by-Step Solution:

Step 1: Evaluate the truthfulness of Assertion (A).

Step 2: Acromegaly is a condition caused by excessive growth hormone (GH) production in adults. If left untreated, it can lead to serious health complications and premature death. Therefore, Assertion (A) is true.

Step 3: Evaluate the truthfulness of Reason (R).

Step 4: ACTH (Adrenocorticotropic hormone) stimulates the adrenal cortex to produce and secrete steroid hormones, including glucocorticoids like cortisol. Therefore, Reason (R) is also true.

Step 5: Determine if Reason (R) explains Assertion (A).

Step 6: Acromegaly is caused by excess GH, not ACTH. Therefore, Reason (R) does not explain Assertion (A).

Why other options are wrong:
- Option A: Reason (R) is true, but it does not explain Assertion (A).
- Option C: Both Assertion (A) and Reason (R) are true.
- Option D: Both Assertion (A) and Reason (R) are true.

Key Concepts:
- Acromegaly
- Growth hormone (GH)
- ACTH
- Glucocorticoids

Memory Aids:
- Acromegaly: Acro- (extremities) + megaly (enlargement) - Enlargement of extremities due to excess GH.
- ACTH: Adrenocorticotropic Hormone - Acts on the adrenal cortex.

Quick Tips:
- Carefully evaluate the truthfulness of both the assertion and the reason before considering their relationship.

65 Easy

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‘ANF’ is a hormone, which

View answer and explanation

Correct option: D

All of the above

Option D (All of the above) is correct because ANF (Atrial Natriuretic Factor) is secreted when blood pressure increases, it decreases blood pressure, and it causes vasodilation.

Solution approach

Correct Answer + Core Reason: All of the above. ANF increases in response to high BP, decreases BP, and causes vasodilation.

Step-by-Step Solution:

Step 1: Define ANF and its function.

Step 2: ANF is secreted by the atrial wall of the heart in response to increased blood volume and pressure.

Step 3: It promotes sodium and water excretion, leading to decreased blood volume and pressure.

Step 4: It also causes vasodilation, further reducing blood pressure.

Why other options are wrong:
- Option A: ANF *is* secreted when blood pressure is increased, making this statement correct.
- Option B: ANF *does* decrease blood pressure by promoting sodium and water excretion, making this statement correct.
- Option C: ANF *does* cause vasodilation, which helps to lower blood pressure, making this statement correct.

Key Concepts:
- Hormones and their functions
- Role of ANF in blood pressure regulation

Memory Aids:
- ANF = Atrial Natriuretic Factor = Sodium excretion

Quick Tips:
- Remember the role of ANF in regulating blood pressure and volume.

66 Easy

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Assertion (A): In old persons, there is gradually weakening of immune system.

Reason (R): It is because of degeneration of thymus gland.

View answer and explanation

Correct option: A

If both A and R are true and R is the correct explanation of A

The correct answer is A (If both A and R are true and R is the correct explanation of A) because the degeneration of the thymus gland in old age directly leads to a weakening of the immune system.

Solution approach

Correct Answer + Core Reason: If both A and R are true and R is the correct explanation of A. Thymus degeneration directly explains the weakened immune system in old age.

Step-by-Step Solution:

Step 1: Analyze the Assertion (A): In old persons, there is gradually weakening of the immune system. This is a well-established fact due to immunosenescence.

Step 2: Analyze the Reason (R): It is because of degeneration of the thymus gland. This is also true; the thymus undergoes involution with age, reducing its function.

Step 3: Determine the relationship between A and R: The degeneration of the thymus gland (R) is the primary reason for the weakening of the immune system (A) in old persons. The thymus is crucial for T-lymphocyte maturation, and its decline directly impacts immune function.

Why other options are wrong:
- Option B: While both statements are true, R *is* the correct explanation of A.
- Option C: R is not false; it's a valid explanation.
- Option D: A is not false; it's a true statement.

Key Concepts:
- Thymus gland
- Immune system
- Aging
- Immunosenescence
- T-lymphocytes

Memory Aids:
- Remember that the thymus is vital for T-cell development, and its decline impacts immunity.

Quick Tips:
- Always consider the direct link between the gland's function and the observed effect.

67 Easy

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The secretin promotes the release of

View answer and explanation

Correct option: C

Water and bicarbonates ions in pancreatic
juice

Option C (Water and bicarbonates ions in pancreatic juice) is correct because secretin stimulates the pancreas to release water and bicarbonate ions, which neutralize the acidic chyme entering the duodenum.

Solution approach

Correct Answer + Core Reason: Water and bicarbonates ions in pancreatic juice. Secretin stimulates the release of water and bicarbonate ions from the pancreas.

Step-by-Step Solution:

Step 1: Recall the function of secretin.

Step 2: Secretin is released in response to acidic chyme in the duodenum.

Step 3: It stimulates the pancreas to release bicarbonate-rich fluid to neutralize the acid.

Step 4: It does not directly promote HCl release.

Step 5: It does not primarily stimulate pancreatic enzyme release (CCK does that).

Why other options are wrong:
- Option A: Secretin does not promote the release of HCl. HCl is secreted by the parietal cells of the stomach.
- Option B: Secretin does not promote the release of HCl. It promotes the release of bicarbonate ions in pancreatic juice, not gastric juice.
- Option D: While secretin can indirectly influence pancreatic enzyme release, its primary role is to stimulate the secretion of water and bicarbonate ions. CCK is the main hormone responsible for stimulating pancreatic enzyme secretion.

Key Concepts:
- Gastrointestinal hormones and their functions
- Role of secretin in pancreatic secretion

Memory Aids:
- Secretin = Secretes bicarbonate

Quick Tips:
- Know the specific functions of the major gastrointestinal hormones.

68 Easy

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I. Non-nutrient,  II. Intercellular messenger,  III. Produced in trace amount,  IV. Intracellular messenger.  Select the correct properties of hormones from above list and then choose the option correct combination

View answer and explanation

Correct option: A

I, II and III

Option A (I, II and III) is correct because hormones are non-nutrient, intercellular messengers produced in trace amounts.

Solution approach

Correct Answer + Core Reason: I, II and III. Hormones are non-nutrient chemicals, intercellular messengers, and produced in trace amounts.

Step-by-Step Solution:

Step 1: Evaluate each statement about hormone properties.

Step 2: Hormones are non-nutrient.

Step 3: Hormones are intercellular messengers.

Step 4: Hormones are produced in trace amounts.

Step 5: Hormones are not intracellular messengers.

Why other options are wrong:
- Option B: Hormones are intercellular, not intracellular, messengers.
- Option C: Hormones are intercellular, not intracellular, messengers.
- Option D: Hormones are intercellular, not intracellular, messengers.

Key Concepts:
- Hormone properties
- Intercellular messengers
- Trace amounts

Memory Aids:
- Hormones = non-nutrient, intercellular, trace

Quick Tips:
- Remember the key characteristics of hormones.

69 Easy

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Assertion (A): GnRH stimulates the pituitary synthesis and release of gonadotropins.

Reason (R): Hypothalamic hormones regulate the synthesis and secretion of pituitary hormones.

View answer and explanation

Correct option: A

If both A and R are true and R is the correct explanation of A

The correct answer is A (If both A and R are true and R is the correct explanation of A) because GnRH's effect on gonadotropin release is an example of hypothalamic control over pituitary hormones.

Solution approach

Correct Answer + Core Reason: If both A and R are true and R is the correct explanation of A. GnRH stimulates gonadotropin release, and this is a specific example of hypothalamic hormones regulating pituitary hormones.

Step-by-Step Solution:

Step 1: Analyze the assertion: GnRH stimulates the pituitary synthesis and release of gonadotropins. This is true.

Step 2: Analyze the reason: Hypothalamic hormones regulate the synthesis and secretion of pituitary hormones. This is also true.

Step 3: Determine if the reason explains the assertion: The reason provides the general principle behind the specific example in the assertion.

Why other options are wrong:
- Option B: The reason *is* a correct explanation of the assertion.
- Option C: The assertion is true, so this option is incorrect.
- Option D: The assertion is true, so this option is incorrect.

Key Concepts:
- GnRH
- Gonadotropins
- Hypothalamic-pituitary axis

Memory Aids:
- GnRH from hypothalamus stimulates pituitary

Quick Tips:
- Remember the hypothalamic-pituitary axis and the hormones involved.

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Assertion: Enlargement of thyroid gland is known as goitre.

Reason: Goitre occurs due to the deficiency of iodine only.

View answer and explanation

Correct option: C

If the assertion is true but the reason is false

Option C (If the assertion is true but the reason is false) is correct because while goiter is indeed the enlargement of the thyroid gland, it can be caused by factors other than just iodine deficiency.

Solution approach

Correct Answer + Core Reason: If the assertion is true but the reason is false. Goitre can be caused by factors other than iodine deficiency.

Step-by-Step Solution:

Step 1: Evaluate the assertion.

Step 2: The assertion that enlargement of the thyroid gland is known as goitre is true.

Step 3: Evaluate the reason.

Step 4: The reason that goitre occurs due to the deficiency of iodine only is false. Goitre can also be caused by other factors such as Grave's disease or thyroid nodules.

Step 5: Therefore, the assertion is true, but the reason is false.

Why other options are wrong:
- Option A: The reason is false, so this option is incorrect.
- Option B: The reason is false, so this option is incorrect.
- Option C: The assertion is true, but the reason is false.
- Option D: The assertion is true, so this option is incorrect.

Key Concepts:
- Endocrine System
- Thyroid Gland
- Goitre
- Iodine Deficiency

Memory Aids:
- Goitre = Growth (thyroid gland enlarges).

Quick Tips:
- Understand the different causes of goitre.

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Hormones released by the neurosecretory cells in hypothalamus regulate the …A… gland. Mainly the neurosecretory hormones are of B… type
Here A and B refers to

View answer and explanation

Correct option: D

A-pituitary; B-two

The correct answer is D because neurosecretory cells in the hypothalamus regulate the pituitary gland, and the neurosecretory hormones are of two types: releasing and inhibiting.

Solution approach

Correct Answer + Core Reason: A-pituitary; B-two. The hypothalamus regulates the pituitary gland with two types of hormones.

Step-by-Step Solution:

Step 1: Recall the relationship between the hypothalamus and the pituitary gland.

Step 2: The hypothalamus controls the pituitary gland by releasing hormones that either stimulate or inhibit the release of pituitary hormones.

Step 3: These hypothalamic hormones are of two types: releasing hormones and inhibiting hormones.

Step 4: The pineal gland is primarily involved in melatonin production and circadian rhythm regulation, not directly regulated by hypothalamic neurosecretory cells.

Why other options are wrong:
- Option A: The hypothalamus regulates the pituitary gland, not the pineal gland.
- Option B: While the hypothalamus does regulate the pituitary, there are only two main types of neurosecretory hormones: releasing and inhibiting.
- Option C: The hypothalamus regulates the pituitary gland, not the pineal gland, and there are two types of hormones.

Key Concepts:
- Hypothalamus-pituitary axis
- Releasing hormones
- Inhibiting hormones

Memory Aids:
- Hypothalamus controls the pituitary.

Quick Tips:
- Understand the hierarchical relationship between the hypothalamus and the pituitary gland.

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Chemically hormones are

View answer and explanation

Correct option: B

Proteins, steroids and biogenic amines

Option B (Proteins, steroids and biogenic amines) is correct because hormones can be derived from proteins, steroids, or biogenic amines.

Solution approach

Correct Answer + Core Reason: Proteins, steroids and biogenic amines. Hormones can be derived from these three classes of molecules.

Step-by-Step Solution:

Step 1: Recall the chemical nature of hormones. Hormones can be classified into three main categories based on their chemical structure: proteins/peptides, steroids, and amino acid derivatives (biogenic amines).

Step 2: Consider examples of each type of hormone. Insulin is a protein hormone, cortisol is a steroid hormone, and epinephrine is a biogenic amine hormone.

Step 3: Analyze the given options.

Why other options are wrong:
- Option A (Biogenic amines only): Incorrect because hormones can also be proteins and steroids.
- Option C (Proteins only): Incorrect because hormones can also be steroids and biogenic amines.
- Option D (Steroids only): Incorrect because hormones can also be proteins and biogenic amines.

Key Concepts:
- Chemical classification of hormones
- Protein hormones
- Steroid hormones
- Biogenic amine hormones

Memory Aids:
- Remember the three classes: Proteins, Steroids, Amines.

Quick Tips:
- Know examples of hormones from each chemical class.

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‘ANF’ is

View answer and explanation

Correct option: B

Peptide hormone

Option B (Peptide hormone) is correct because ANF (Atrial Natriuretic Factor) is a hormone composed of amino acids, classifying it as a peptide hormone.

Solution approach

Correct Answer + Core Reason: Peptide hormone. ANF (Atrial Natriuretic Factor) is a peptide hormone secreted by the heart.

Step-by-Step Solution:

Step 1: ANF (Atrial Natriuretic Factor) is a hormone secreted by the atrial cells of the heart in response to increased blood volume and pressure.

Step 2: ANF is a peptide hormone, meaning it is composed of amino acids linked together by peptide bonds.

Step 3: ANF acts on the kidneys to promote the excretion of sodium and water, thereby reducing blood volume and pressure.

Why other options are wrong:
- Option A: Steroidal hormones are derived from cholesterol and have a different chemical structure than ANF.
- Option C: Glucocorticoid hormones, such as cortisol, are produced by the adrenal cortex and are involved in glucose metabolism.
- Option D: Mineralocorticoid hormones, such as aldosterone, are produced by the adrenal cortex and regulate electrolyte balance.

Key Concepts:
- ANF (Atrial Natriuretic Factor)
- Peptide hormone
- Steroidal hormone
- Glucocorticoid
- Mineralocorticoid

Memory Aids:
- ANF is a \"factor,\" and factors are often peptides.

Quick Tips:
- Know the different classes of hormones based on their chemical structure.

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The posterior pituitary gland is not a ‘true’ endocrine gland because

View answer and explanation

Correct option: C

it only stores and releases hormones

Option C is correct because the posterior pituitary only stores and releases hormones that are produced by the hypothalamus, not synthesizing them itself.

Solution approach

Correct Answer + Core Reason: it only stores and releases hormones. The posterior pituitary stores and releases hormones synthesized in the hypothalamus.

Step-by-Step Solution:

Step 1: Understand the function of the posterior pituitary gland.

Step 2: The posterior pituitary (neurohypophysis) is responsible for storing and releasing two hormones: vasopressin (ADH) and oxytocin. These hormones are synthesized in the hypothalamus and transported to the posterior pituitary for storage.

Step 3: Analyze the given options based on the function of the posterior pituitary.

Step 4: Option C accurately describes the posterior pituitary's role as a storage and release site for hormones produced elsewhere.

Why other options are wrong:
- Option A: it secretes enzymes - The posterior pituitary does not secrete enzymes; it releases hormones.
- Option B: it is provided with a duct - Endocrine glands are ductless; hormones are secreted directly into the bloodstream. The posterior pituitary is an endocrine gland.
- Option D: it is under the regulation of hypothalamus - While the hypothalamus regulates the posterior pituitary, this is not the primary reason it's not a 'true' endocrine gland. The key reason is its lack of hormone synthesis.

Key Concepts:
- Endocrine glands
- Posterior pituitary function
- Hypothalamus-pituitary axis

Memory Aids:
- Posterior = Storage and Release

Quick Tips:
- Differentiate between hormone synthesis and hormone storage/release.

75 Easy

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Which one of the following is not an endocrine gland?

View answer and explanation

Correct option: A

Kidney

Option A (Kidney) is correct because while the kidney produces hormones, it is primarily an excretory organ, not solely an endocrine gland.

Solution approach

Correct Answer + Core Reason: Kidney. While the kidney produces hormones, it is primarily an excretory organ.

Step-by-Step Solution:

Step 1: Recall the primary function of the kidney. The kidney's main function is to filter blood and produce urine, removing waste products from the body.

Step 2: Consider the other options. The thyroid, adrenal, and pituitary glands are primarily endocrine glands, whose main function is to produce and secrete hormones.

Step 3: While the kidney does produce hormones like erythropoietin and renin, its primary role is not endocrine.

Why other options are wrong:
- Option B (Thyroid): Incorrect because the thyroid is primarily an endocrine gland.
- Option C (Adrenal): Incorrect because the adrenal gland is primarily an endocrine gland.
- Option D (Pituitary): Incorrect because the pituitary gland is primarily an endocrine gland.

Key Concepts:
- Endocrine glands
- Kidney function

Memory Aids:
- Think of the kidney as a filter first, hormone producer second.

Quick Tips:
- Consider the primary function of each organ when determining whether it is an endocrine gland.

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Which of the following would help in prevention of diuresis?

View answer and explanation

Correct option: A

Reabsorption of

N{a^ + }

and water from renal tubules due to aldosterone

Option A (Reabsorption of

N{a^ + }

and water from renal tubules due to aldosterone) is correct because aldosterone promotes sodium and water reabsorption, preventing diuresis.

Solution approach

Correct Answer + Core Reason: Reabsorption of $N{a^ + }$ and water from renal tubules due to aldosterone. Aldosterone promotes sodium and water reabsorption, which helps prevent diuresis (excessive urine production).

Step-by-Step Solution:

Step 1: Define diuresis and identify factors that prevent it.

Step 2: Diuresis is increased or excessive production of urine.

Step 3: Aldosterone increases $N{a^ + }$ reabsorption in the distal convoluted tubule and collecting duct of the nephron. Water follows sodium due to osmosis, leading to increased water reabsorption and reduced urine volume.

Step 4: Atrial natriuretic factor (ANF) causes vasodilation and increases sodium excretion, promoting diuresis, not preventing it.

Step 5: A decrease in renin secretion would lead to decreased aldosterone production, which would promote diuresis, not prevent it.

Step 6: Under secretion of ADH (antidiuretic hormone) leads to less water reabsorption, resulting in increased urine volume and diuresis.

Final Answer: Reabsorption of $N{a^ + }$ and water from renal tubules due to aldosterone.

Why other options are wrong:
- **Option A (Reabsorption of $N{a^ + }$ and water from renal tubules due to aldosterone): This is the correct answer as explained above.
- Option B (Atrial natriuretic factor causes vasoconstriction): ANF causes vasodilation, not vasoconstriction, and promotes diuresis.
- Option C (Decrease in secretion of renin by JG cells): Decreased renin leads to decreased aldosterone, promoting diuresis.
- Option D (More water reabsorption due to under secretion of ADH): Under secretion of ADH leads to less water reabsorption and increased diuresis.

Key Concepts:
- Aldosterone function in sodium and water reabsorption
- ADH function in water reabsorption
- ANF function
- Renin-angiotensin-aldosterone system

Memory Aids:
- Aldosterone: "Salt, Save, Sodium" (promotes sodium reabsorption)
- ADH: "Anti-Diuretic Hormone" (prevents diuresis)

Quick Tips:**
- Understand the roles of aldosterone and ADH in regulating fluid balance.

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Hormones which interact with intracellular receptors are:  I. Steroid hormones,  II. ACTH,  IIII. Iodothyronines,  IV. MSH.  Choose the option with correct combination

View answer and explanation

Correct option: A

I and III

The correct answer is A (I and III) because steroid hormones and iodothyronines interact with intracellular receptors.

Solution approach

Correct Answer + Core Reason: I and III. Steroid hormones and iodothyronines (thyroid hormones) interact with intracellular receptors.

Step-by-Step Solution:

Step 1: Recall the mechanism of action of different hormone types.

Step 2: Steroid hormones (I) are lipid-soluble and bind to intracellular receptors.

Step 3: Iodothyronines (III) (thyroid hormones) also bind to intracellular receptors.

Step 4: ACTH (II) and MSH (IV) are peptide hormones and bind to cell surface receptors.

Why other options are wrong:
- Option B: ACTH and MSH are peptide hormones and bind to cell surface receptors.
- Option C: ACTH is a peptide hormone and binds to cell surface receptors, while iodothyronines bind to intracellular receptors.
- Option D: MSH is a peptide hormone and binds to cell surface receptors, while steroid hormones bind to intracellular receptors.

Key Concepts:
- Hormone receptors
- Intracellular receptors
- Cell surface receptors
- Steroid hormones
- Thyroid hormones
- Peptide hormones

Memory Aids:
- Steroids and thyroid: intracellular; Peptides: cell surface

Quick Tips:
- Remember that lipid-soluble hormones bind to intracellular receptors.

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Which is a secretion of exocrine gland:

View answer and explanation

Correct option: D

Both 1 and 3

Option D (Both 1 and 3) is correct because saliva and digestive enzymes are both secreted by exocrine glands through ducts.

Solution approach

Correct Answer + Core Reason: Both 1 and 3. Saliva and digestive enzymes are secreted by exocrine glands.

Step-by-Step Solution:

Step 1: Recall the difference between exocrine and endocrine glands.

Step 2: Consider the secretions of each gland:\nA. Saliva: Exocrine gland secretion.\nB. Thyroxine: Endocrine gland secretion.\nC. Digestive enzyme: Exocrine gland secretion.\nD. Both 1 and 3: Saliva and digestive enzymes are exocrine secretions.

Step 3: Identify the exocrine gland secretions.

Why other options are wrong:
- Option A: Saliva is an exocrine secretion, but not the only one.
- Option B: Thyroxine is an endocrine secretion.
- Option C: Digestive enzymes are exocrine secretions, but not the only one.

Key Concepts:\nExocrine glands, endocrine glands, saliva, thyroxine, digestive enzymes

Memory Aids:\nRemember that exocrine glands secrete through ducts, while endocrine glands secrete directly into the bloodstream.

Quick Tips:\nDistinguish between exocrine and endocrine secretions.

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Acromegaly is caused by

View answer and explanation

Correct option: A

Excess of STH

Option A (Excess of STH) is correct because acromegaly is caused by excessive secretion of Somatotropin (STH), also known as growth hormone, after the growth plates have closed.

Solution approach

Correct Answer + Core Reason: Excess of STH. Acromegaly is caused by excessive growth hormone (STH).

Step-by-Step Solution:

Step 1: Define acromegaly. Acromegaly is a hormonal disorder that develops when the pituitary gland produces too much growth hormone (STH) after the growth plates have closed.

Step 2: Consider the options:
- Excess of STH: This is the direct cause of acromegaly.
- Excess of thyroxine: This causes hyperthyroidism.
- Deficiency of thyroxine: This causes hypothyroidism.
- Excess of adrenaline: This can cause symptoms related to stress and anxiety.

Step 3: Therefore, acromegaly is caused by an excess of STH.

Why other options are wrong:
- Option B: Excess of thyroxine causes hyperthyroidism, not acromegaly.
- Option C: Deficiency of thyroxine causes hypothyroidism, not acromegaly.
- Option D: Excess of adrenaline causes symptoms related to stress and anxiety, not acromegaly.

Key Concepts:
- Acromegaly
- Growth hormone (STH)

Memory Aids:
- Acro- (extremities) + megaly (enlargement) = Acromegaly (enlargement of extremities due to excess STH).

Quick Tips:
- Associate acromegaly specifically with excess growth hormone.

80 Easy

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I. Sleep-wake cycle, II. Body temperature,  III. Pigmentation,  IV. Metabolism,  V. Defence capability.  All of the above written activities are influenced/regulated by

View answer and explanation

Correct option: A

Pineal gland

Option A (Pineal gland) is correct because the pineal gland secretes melatonin, which influences the sleep-wake cycle, body temperature, pigmentation, metabolism, and defense capability.

Solution approach

Correct Answer + Core Reason: Pineal gland. The pineal gland secretes melatonin, which regulates various bodily functions.

Step-by-Step Solution:

Step 1: Identify the functions listed in the question: sleep-wake cycle, body temperature, pigmentation, metabolism, and defense capability.

Step 2: Recall the hormones secreted by each gland and their functions.

Step 3: The pineal gland secretes melatonin, which influences the sleep-wake cycle (circadian rhythm), body temperature, and pigmentation. It also indirectly affects metabolism and immune function.

Step 4: The other glands have different primary functions. The parathyroid gland regulates calcium levels, the thymus gland is involved in immune system development, and the adrenal gland produces hormones related to stress response and electrolyte balance.

Why other options are wrong:
- Option B: Parathyroid gland primarily regulates calcium levels in the blood.
- Option C: Thymus gland is mainly involved in the development of the immune system, particularly T-lymphocytes.
- Option D: Adrenal gland produces hormones like cortisol and adrenaline, which are related to stress response and electrolyte balance, but not all the listed functions.

Key Concepts:
- Endocrine glands and their hormones
- Functions of melatonin
- Regulation of circadian rhythm

Memory Aids:
- Pineal = Pigmentation, Sleep

Quick Tips:
- Remember the primary function of each endocrine gland to quickly eliminate incorrect options.

81 Easy

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Cretinism, mental retardation, low intelligence quotient, abnormal skin, deaf-mutism, etc. are the results of

View answer and explanation

Correct option: C

Hypothyroidism

Option C (Hypothyroidism) is correct because cretinism, mental retardation, low intelligence quotient, abnormal skin, and deaf-mutism are all symptoms of hypothyroidism, especially when it occurs during infancy or childhood.

Solution approach

Correct Answer + Core Reason: Hypothyroidism. These symptoms are characteristic of hypothyroidism, especially in infants and children.

Step-by-Step Solution:

Step 1: Identify the symptoms: cretinism, mental retardation, low intelligence quotient, abnormal skin, deaf-mutism.

Step 2: Consider the possible causes related to each option.

Step 3: Hyperthyroidism typically causes anxiety, weight loss, and rapid heartbeat, not the listed symptoms.

Step 4: Goitre is an enlargement of the thyroid gland, which can be caused by both hyperthyroidism and hypothyroidism, but it doesn't directly cause all the listed symptoms.

Step 5: Hypothyroidism, especially during infancy or childhood, can lead to cretinism, characterized by stunted growth, mental retardation, abnormal skin, and deaf-mutism.

Why other options are wrong:
- Option A: Hyperthyroidism causes different symptoms like anxiety and weight loss.
- Option B: Goitre is a symptom of thyroid enlargement but does not directly cause all the listed conditions.
- Option D: While goitre can be associated with hypothyroidism, it doesn't directly cause all the listed symptoms.

Key Concepts:
- Hypothyroidism and its effects
- Cretinism

Memory Aids:
- Hypothyroidism = Mental retardation, stunted growth

Quick Tips:
- Recognize the symptoms of hypothyroidism, especially in infants and children.

82 Easy

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Melatonin is secreted by

View answer and explanation

Correct option: D

Pineal gland

Option D (Pineal gland) is correct because the pineal gland is responsible for secreting melatonin, which regulates sleep-wake cycles.

Solution approach

Correct Answer + Core Reason: Pineal gland. Melatonin is secreted by the pineal gland.

Step-by-Step Solution:

Step 1: Recall the function of each gland.

Step 2: Skin: Primarily involved in protection and vitamin D synthesis.

Step 3: Thymus: Involved in immune system development.

Step 4: Pituitary: Secretes various hormones, including growth hormone and reproductive hormones.

Step 5: Pineal gland: Secretes melatonin, which regulates sleep-wake cycles.

Step 6: Therefore, melatonin is secreted by the pineal gland.

Why other options are wrong:
- Option A: The skin does not secrete melatonin.
- Option B: The thymus does not secrete melatonin.
- Option C: The pituitary gland does not secrete melatonin.

Key Concepts:
- Pineal gland function
- Melatonin secretion

Memory Aids:
- Pineal = Melatonin = Sleep.

Quick Tips:
- Remember the direct association between the pineal gland and melatonin.

83 Easy

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Assertion: Hormones are nutrient substances which act as intercellular messengers.

Reason: Hormones are produced in large amount.

View answer and explanation

Correct option: D

If both the assertion and reason are false

Option D (If both the assertion and reason are false) is correct because hormones are not nutrient substances and are produced in trace amounts, not large amounts.

Solution approach

Correct Answer + Core Reason: If both the assertion and reason are false. Hormones are not nutrients and are produced in small amounts.

Step-by-Step Solution:

Step 1: Analyze the assertion: Hormones are nutrient substances which act as intercellular messengers. Hormones are not nutrients; they are signaling molecules.

Step 2: Analyze the reason: Hormones are produced in large amount. Hormones are produced in trace amounts and have significant effects even at low concentrations.

Step 3: Since both the assertion and the reason are false, the correct option is D.

Why other options are wrong:
- Option A: Both assertion and reason are false, so this option is incorrect.
- Option B: Both assertion and reason are false, so this option is incorrect.
- Option C: The assertion is false, so this option is incorrect.

Key Concepts:
- Definition of hormones
- Role of hormones as signaling molecules
- Amount of hormone production

Memory Aids:
- Hormones = Messengers, not nutrients

Quick Tips:
- Understand the fundamental nature of hormones to evaluate assertions and reasons correctly.

84 Easy

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Pancreatic juice and hormones of pancreas are produced by

View answer and explanation

Correct option: D

Different cells

Option D (Different cells) is correct because pancreatic juice is produced by exocrine cells (acinar cells), while pancreatic hormones are produced by endocrine cells (islets of Langerhans).

Solution approach

Correct Answer + Core Reason: Different cells. Pancreatic juice is produced by exocrine cells, while hormones are produced by endocrine cells.

Step-by-Step Solution:
Step 1: Recall the structure of the pancreas.
Step 2: The pancreas has both exocrine and endocrine functions.
Step 3: Exocrine function: Acinar cells produce pancreatic juice containing digestive enzymes.
Step 4: Endocrine function: Islets of Langerhans contain cells (alpha, beta, delta) that produce hormones (glucagon, insulin, somatostatin).

Why other options are wrong:
- Option A: Same cells cannot produce both pancreatic juice and hormones due to their different cellular machinery and functions.
- Option B: Same cells at different times is incorrect because the cells are specialized for either exocrine or endocrine function.
- Option C: The statement is not wrong, so this option is incorrect.

Key Concepts:
- Pancreas
- Exocrine function
- Endocrine function
- Acinar cells
- Islets of Langerhans

Memory Aids:
- Exocrine = Enzymes
- Endocrine = Hormones

Quick Tips:
- Remember that the pancreas has both exocrine and endocrine functions performed by different cell types.

85 Easy

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Which one of the following endocrine glands functions as a biological clock and a neurosecretory transducer?

View answer and explanation

Correct option: C

Pineal gland

Option C (Pineal gland) is correct because the pineal gland secretes melatonin, which regulates sleep-wake cycles and is influenced by light, making it a biological clock and neurosecretory transducer.

Solution approach

Correct Answer + Core Reason: Pineal gland. The pineal gland secretes melatonin, regulating sleep-wake cycles and acting as a biological clock.

Step-by-Step Solution:

Step 1: Recall the function of each endocrine gland.

Step 2: Adrenal gland: Produces hormones like cortisol and adrenaline, involved in stress response.

Step 3: Thyroid gland: Produces thyroid hormones, regulating metabolism.

Step 4: Pineal gland: Produces melatonin, regulating sleep-wake cycles and circadian rhythms.

Step 5: Thymus gland: Involved in immune system development.

Step 6: The pineal gland's secretion of melatonin is influenced by light and darkness, making it a biological clock and a neurosecretory transducer.

Why other options are wrong:
- Option A: The adrenal gland primarily regulates stress response and electrolyte balance, not directly sleep-wake cycles.
- Option B: The thyroid gland regulates metabolism, not sleep-wake cycles.
- Option D: The thymus gland is involved in immune function, not sleep-wake cycles.

Key Concepts:
- Pineal gland function
- Melatonin secretion
- Biological clock

Memory Aids:
- Pineal = Sleep (Think of \"pine needles\" associated with nighttime).

Quick Tips:
- Focus on the specific hormones secreted by each gland and their primary functions.

86 Easy

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ANF has exactly opposite function of which of hormone secreted

View answer and explanation

Correct option: C

Aldosterone

Option C (Aldosterone) is correct because ANF (Atrial Natriuretic Factor) decreases blood pressure and sodium reabsorption, while aldosterone increases them.

Solution approach

Correct Answer + Core Reason: Aldosterone. ANF decreases blood pressure and sodium reabsorption, while aldosterone increases them, making them opposite in function.

Step-by-Step Solution:
Step 1: Define ANF and its function.
Step 2: ANF (Atrial Natriuretic Factor) is released by the heart in response to high blood volume or pressure.
Step 3: ANF promotes sodium and water excretion, thus lowering blood pressure.
Step 4: Recall the function of aldosterone.
Step 5: Aldosterone is released by the adrenal cortex and promotes sodium and water reabsorption, thus increasing blood pressure.

Why other options are wrong:
- Option A: PTH (Parathyroid Hormone) regulates calcium levels, not directly related to ANF's function.
- Option B: Estrogen is a female sex hormone with various functions not directly related to ANF's function.
- Option D: Androgen is a male sex hormone with various functions not directly related to ANF's function.

Key Concepts:
- ANF
- Aldosterone
- Blood pressure regulation
- Sodium balance

Memory Aids:
- ANF = Anti-sodium
- Aldosterone = Sodium retention

Quick Tips:
- Remember that ANF and aldosterone have opposing effects on blood pressure and sodium balance.

87 Easy

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Hypophyseal portal system is present between

View answer and explanation

Correct option: B

Hypothalamus and pituitary gland

Option B (Hypothalamus and pituitary gland) is correct because the hypophyseal portal system connects the hypothalamus to the anterior pituitary gland, allowing for hormonal communication.

Solution approach

Correct Answer + Core Reason: Hypothalamus and pituitary gland. The hypophyseal portal system connects the hypothalamus to the anterior pituitary gland.

Step-by-Step Solution:

Step 1: Recall the location of the hypophyseal portal system.

Step 2: The hypophyseal portal system is a specialized capillary network that connects the hypothalamus to the anterior pituitary gland (adenohypophysis).

Step 3: This system allows hypothalamic hormones to directly regulate the secretion of pituitary hormones.

Why other options are wrong:
- Option A: Hypothalamus and liver: There is no direct portal system between the hypothalamus and liver.
- Option C: Hypophysis and liver: There is no direct portal system between the pituitary gland and liver.
- Option D: Hypophysis and abdominal organs: There is no direct portal system between the pituitary gland and abdominal organs.

Key Concepts:
- Hypophyseal portal system
- Hypothalamus-pituitary axis

Memory Aids:
- Hypophyseal = pituitary; portal = connection between two capillary beds.

Quick Tips:
- Remember the role of the hypothalamus in regulating the pituitary gland.

88 Easy

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Which one is not a secondary messenger?

View answer and explanation

Correct option: D

N{a^ + }

Option D (

N{a^ + }

) is correct because sodium ions are not typically considered secondary messengers in cellular signaling pathways.

Solution approach

Correct Answer + Core Reason: $N{a^ + }$ . Sodium ions are not typically considered secondary messengers.

Step-by-Step Solution:

Step 1: Recall the common secondary messengers in cellular signaling.

Step 2: Identify cyclic AMP, $I{P_3}$ , and $C{a^{ + 2}}$ as common secondary messengers.

Step 3: Recognize that $N{a^ + }$ is primarily involved in nerve impulse transmission and maintaining membrane potential, not as a secondary messenger.

Step 4: Conclude that $N{a^ + }$ is not a secondary messenger.

Why other options are wrong:
- Option A: Cyclic AMP is a well-known secondary messenger.
- Option B: $I{P_3}$ (inositol trisphosphate) is a secondary messenger involved in calcium release.
- Option C: $C{a^{ + 2}}$ (calcium ions) is a common secondary messenger.

Key Concepts:
- Secondary messengers
- Cyclic AMP
- $I{P_3}$
- $C{a^{ + 2}}$
- Signal transduction

Memory Aids:
- Common secondary messengers: cAMP, IP3, Calcium

Quick Tips:
- Remember the key secondary messengers and their roles in cellular signaling.

89 Easy

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A patient with a pituitary tumor might suffer with polyuria (production of too much urine) as a result of decreased secretion of

View answer and explanation

Correct option: D

ADH

The correct answer is D (ADH) because decreased secretion of ADH leads to polyuria due to reduced water reabsorption in the kidneys.

Solution approach

Correct Answer + Core Reason: ADH. Decreased secretion of ADH (antidiuretic hormone) leads to polyuria due to reduced water reabsorption in the kidneys.

Step-by-Step Solution:

Step 1: Understand the function of ADH.

Step 2: ADH promotes water reabsorption in the kidneys.

Step 3: A decrease in ADH secretion results in less water being reabsorbed, leading to increased urine production (polyuria).

Why other options are wrong:
- Option A: MSH (melanocyte-stimulating hormone) is involved in pigmentation and does not directly affect urine production.
- Option B: FSH (follicle-stimulating hormone) is a gonadotropin involved in reproductive function and does not directly affect urine production.
- Option C: Aldosterone promotes sodium reabsorption and potassium excretion, indirectly affecting water balance, but a decrease in ADH is the most direct cause of polyuria in this context.

Key Concepts:
- Antidiuretic hormone (ADH)
- Water reabsorption in kidneys
- Polyuria

Memory Aids:
- ADH: Anti-Diuretic Hormone (reduces urine)

Quick Tips:
- Remember that ADH directly affects water reabsorption in the kidneys.

90 Easy

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How many hormones given below are secreted from adenohypophysis? ADH. PRL. TSH. ACTH. MSH. GnRH

View answer and explanation

Correct option: D

4

Option D is correct because PRL, TSH, ACTH, and MSH are all secreted from the adenohypophysis, while ADH and GnRH are not.

Solution approach

Correct Answer + Core Reason: 4. PRL, TSH, ACTH, and MSH are secreted from the adenohypophysis.

Step-by-Step Solution:

Step 1: List the hormones provided: ADH, PRL, TSH, ACTH, MSH, GnRH.

Step 2: Recall the origin of each hormone:
- ADH (Antidiuretic Hormone): Posterior Pituitary (released, but synthesized in hypothalamus)
- PRL (Prolactin): Anterior Pituitary (adenohypophysis)
- TSH (Thyroid-Stimulating Hormone): Anterior Pituitary (adenohypophysis)
- ACTH (Adrenocorticotropic Hormone): Anterior Pituitary (adenohypophysis)
- MSH (Melanocyte-Stimulating Hormone): Intermediate lobe of Pituitary (derived from adenohypophysis)
- GnRH (Gonadotropin-Releasing Hormone): Hypothalamus

Step 3: Count the hormones secreted from the adenohypophysis: PRL, TSH, ACTH, MSH (4 hormones).

Why other options are wrong:
- Option A: 1 is incorrect because there are 4 hormones secreted from the adenohypophysis.
- Option B: 2 is incorrect because there are 4 hormones secreted from the adenohypophysis.
- Option C: 3 is incorrect because there are 4 hormones secreted from the adenohypophysis.

Key Concepts:
- Hormones secreted by the adenohypophysis
- Hormones secreted by the neurohypophysis (stored, but synthesized in hypothalamus)
- Hypothalamic hormones

Memory Aids:
- FLAT PiG (FSH, LH, ACTH, TSH, Prolactin, GH) - Hormones of Anterior Pituitary

Quick Tips:
- Memorize the hormones secreted by the anterior and posterior pituitary glands.

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