By Shripal Dhewa
Welcome to the ultimate revision guide for NEET 2025 on Chemical Coordination and Integration. This blog post presents 100 advanced MCQs designed to challenge your understanding of complex concepts—from hormone signaling and feedback regulation to diagram–based and numerical questions. Detailed explanations are provided for many of the complex questions to help clarify the correct answers and deepen your conceptual understanding. Study these questions carefully to boost your exam readiness!
- Which of the following best describes how a lipid–soluble hormone acts on a target cell?
1. It binds to a receptor on the cell membrane and activates a second messenger.
2. It diffuses through the cell membrane, binds to a cytoplasmic receptor, and then translocates to the nucleus to alter gene transcription.
3. It is stored in vesicles for rapid release upon stimulation.
4. It binds extracellular proteins to initiate a cascade.
Answer: 2
Explanation: Lipid–soluble hormones easily diffuse through the cell membrane and typically bind to intracellular receptors that then migrate to the nucleus, where they affect gene transcription. - In endocrine signaling, “hormone receptor specificity” means that:
1. A hormone can bind to any receptor in the body.
2. A hormone binds only to a specific receptor on its target cell.
3. Multiple hormones share a common receptor.
4. Receptors change shape to accommodate various hormones.
Answer: 2
Explanation: This specificity ensures that only target cells with the appropriate receptor will respond to a given hormone. - Which statement best differentiates endocrine from paracrine signaling?
1. Endocrine signals act locally while paracrine signals travel long distances.
2. Endocrine signals are secreted into the bloodstream to act on distant targets; paracrine signals act on nearby cells.
3. Both types use the same mechanism of action.
4. Paracrine signaling requires synaptic connections.
Answer: 2 - Which gland is primarily responsible for secreting the hormone that regulates the basal metabolic rate?
1. Pituitary
2. Thyroid
3. Adrenal
4. Pancreas
Answer: 2 - Which of the following is NOT considered an endocrine gland?
1. Pituitary
2. Thyroid
3. Liver
4. Adrenal
Answer: 3 - The hormone insulin is secreted by the:
1. Alpha cells of the pancreas
2. Beta cells of the pancreas
3. Delta cells of the pancreas
4. Acinar cells of the pancreas
Answer: 2 - Glucagon, which raises blood glucose levels, is secreted by the:
1. Beta cells of the pancreas
2. Alpha cells of the pancreas
3. Delta cells of the pancreas
4. Gamma cells of the pancreas
Answer: 2 - Select the correct pairing of hormone and its main metabolic target:
1. Thyroxine – skeletal muscle
2. Cortisol – liver
3. Insulin – adipose tissue
4. Glucagon – kidney
Answer: 2
Explanation: Cortisol acts mainly on the liver to promote gluconeogenesis and increase blood glucose levels. - Which hormone primarily acts to lower blood calcium levels?
1. Parathyroid hormone (PTH)
2. Calcitonin
3. Aldosterone
4. Cortisol
Answer: 2
Explanation: Calcitonin, secreted by the thyroid, lowers blood calcium levels by inhibiting osteoclast activity. - A hormone that increases water reabsorption in the kidney is:
1. Insulin
2. Glucagon
3. Antidiuretic hormone (ADH)
4. Thyroxine
Answer: 3 - Select the statement that best describes the principle of negative feedback in endocrine regulation:
1. An increase in hormone levels further stimulates hormone secretion.
2. An increase in a target hormone leads to reduced secretion of its stimulating hormone.
3. A decrease in hormone levels causes a decrease in stimulating hormone secretion.
4. Hormone levels are regulated without feedback.
Answer: 2 - When blood glucose levels fall, which hormone is secreted to restore normoglycemia?
1. Insulin
2. Glucagon
3. Cortisol
4. ADH
Answer: 2 - The coordinated action of insulin and glucagon in blood glucose regulation is an example of:
1. Synergistic action
2. Antagonistic action
3. Additive action
4. Independent action
Answer: 2 - The hormone cortisol is primarily secreted by the:
1. Adrenal medulla
2. Adrenal cortex
3. Pancreas
4. Pituitary
Answer: 2 - Which statement best describes the difference between water–soluble and lipid–soluble hormones?
1. Water–soluble hormones easily cross the cell membrane.
2. Lipid–soluble hormones bind only to cell surface receptors.
3. Water–soluble hormones act quickly and are degraded rapidly, whereas lipid–soluble hormones act via intracellular receptors with longer-lasting effects.
4. There is no difference.
Answer: 3 - The delay in the action of a hormone that affects gene transcription is primarily due to:
1. Slow diffusion through blood.
2. The time needed for the hormone–receptor complex to modulate gene transcription.
3. Rapid receptor recycling.
4. Immediate second messenger activation.
Answer: 2 - A diagram (Diagram 1) shows a hormone binding to a receptor on the cell membrane and activating a cascade that produces cAMP. In this diagram, what represents the “second messenger”?
1. The hormone molecule
2. The receptor
3. The cAMP molecules
4. The enzyme at the receptor
Answer: 3
Explanation: cAMP is produced intracellularly after receptor activation and acts as a second messenger to amplify the hormone signal.
Diagram 1:
[Hormone] → [Receptor] → [cAMP] → Cellular Response - A diagram (Diagram 2) illustrates an endocrine feedback loop: the hypothalamus releases a releasing hormone, stimulating the pituitary to secrete a tropic hormone, which then stimulates a peripheral gland to release its hormone. The peripheral hormone feeds back to inhibit the hypothalamus and pituitary. In this diagram, which component is the source of negative feedback?
1. The hypothalamus
2. The tropic hormone
3. The peripheral gland hormone
4. The releasing hormone
Answer: 3
Explanation: The hormone produced by the peripheral gland exerts negative feedback by inhibiting further secretion from the hypothalamus and pituitary.
Diagram 2:
Hypothalamus → Pituitary → Peripheral Gland → (Feedback arrow back to Hypothalamus/Pituitary) - A diagram (Diagram 3) displays two signaling pathways: one rapid (via ion channels) and one delayed (via gene transcription). Which type of hormone is most likely responsible for the delayed pathway?
1. Peptide hormone
2. Steroid or thyroid hormone
3. Catecholamine
4. Amino acid–derived hormone
Answer: 2
Explanation: Steroid and thyroid hormones typically act by modulating gene transcription, a process that takes longer to manifest than immediate ion channel effects.
Diagram 3:
Pathway A: Fast → Ion Channel Change Pathway B: Slow → Nucleus → Gene Transcription - Which statement correctly defines “hormone half–life”?
1. The time required for the hormone’s concentration to double.
2. The time required for half of the hormone molecules to be degraded or cleared from circulation.
3. The time for the hormone to bind to its receptor.
4. The duration of hormone synthesis.
Answer: 2 - During prolonged fasting, which hormone is expected to be elevated?
1. Insulin
2. Glucagon
3. Thyroxine
4. ADH
Answer: 2 - Which hormone primarily maintains blood pressure by regulating sodium retention?
1. Insulin
2. Aldosterone
3. Glucagon
4. Thyroxine
Answer: 2 - “Hormone receptor specificity” means that a hormone:
1. Binds to any receptor on any cell.
2. Binds only to its specific receptor on target cells.
3. Can bind to multiple receptors simultaneously.
4. Changes its structure to bind different receptors.
Answer: 2 - The rapid actions of some hormones are due to their ability to:
1. Immediately change gene transcription.
2. Activate second messenger systems that quickly modify cellular activity.
3. Bind irreversibly to receptors.
4. Undergo rapid degradation.
Answer: 2 - A hormone that is released in a pulsatile manner from the hypothalamus is:
1. Thyrotropin–releasing hormone (TRH)
2. Gonadotropin–releasing hormone (GnRH)
3. Growth hormone–releasing hormone (GHRH)
4. Corticotropin–releasing hormone (CRH)
Answer: 2 - In type 1 diabetes, the primary defect is:
1. Excess insulin production
2. Autoimmune destruction of pancreatic beta cells leading to insulin deficiency
3. Insulin resistance in peripheral tissues
4. Overproduction of glucagon
Answer: 2 - Excess secretion of cortisol leads to which condition?
1. Addison’s disease
2. Cushing’s syndrome
3. Acromegaly
4. Hypothyroidism
Answer: 2 - A deficiency in growth hormone during childhood results in:
1. Gigantism
2. Dwarfism
3. Acromegaly
4. Hyperthyroidism
Answer: 2 - Low thyroid hormone levels with high TSH indicate:
1. Primary hypothyroidism
2. Secondary hypothyroidism
3. Hyperthyroidism
4. Normal thyroid function
Answer: 1
Explanation: In primary hypothyroidism, the thyroid gland is failing; hence, TSH is elevated due to lack of negative feedback. - A mutation that reduces the sensitivity of hormone receptors most likely causes:
1. Hormone excess
2. Hormone resistance
3. Increased receptor expression
4. No change in hormone action
Answer: 2 - Hormone levels are maintained within a narrow range by:
1. Constant, unregulated secretion
2. Positive feedback mechanisms
3. Negative feedback mechanisms
4. Irreversible receptor binding
Answer: 3 - In a feedback loop, an increase in peripheral hormone levels typically results in:
1. Increased stimulating hormone secretion
2. Decreased stimulating hormone secretion
3. No change in stimulating hormone secretion
4. Random fluctuations
Answer: 2 - A hormone that exhibits diurnal variation with peak levels in the early morning is:
1. Insulin
2. Cortisol
3. Glucagon
4. ADH
Answer: 2 - [Diagram 4] A flowchart shows a hormone binding to its receptor and activating an intracellular cascade that leads to gene transcription. The final step, occurring in the nucleus, is responsible for the hormone’s:
1. Immediate effect
2. Long–term effect
3. Rapid ion channel modulation
4. Receptor recycling
Answer: 2
Explanation: The nuclear step involves changes in gene transcription that lead to long-term cellular responses.
Diagram 4:
Hormone → Receptor → Second Messenger → Nucleus → Gene Transcription - Some hormones have prolonged effects because they:
1. Are rapidly degraded.
2. Initiate changes in gene expression that persist over time.
3. Are stored indefinitely in the bloodstream.
4. Bind irreversibly to receptors.
Answer: 2 - [Diagram 5] A dose–response curve shows a plateau at high hormone concentrations. The plateau indicates:
1. Hormone degradation
2. Receptor saturation
3. Receptor hypersensitivity
4. Increased hormone clearance
Answer: 2
Explanation: Once all receptors are occupied, further increases in hormone concentration do not increase the response.
Diagram 5:
Response ↑ | ______ | / |_______/ +----------------→ Hormone Concentration - Insulin’s primary action is to:
1. Stimulate cellular glucose uptake and glycogen synthesis.
2. Increase blood glucose via glycogenolysis.
3. Act as a stress hormone.
4. Be secreted in response to low blood glucose.
Answer: 1 - Peptide hormones typically act by:
1. Being lipid–soluble and acting via nuclear receptors.
2. Being water–soluble, binding to cell surface receptors, and activating intracellular cascades.
3. Directly binding to DNA.
4. Functioning without any receptor.
Answer: 2 - [Diagram 6] Two cells are shown; one has high receptor density and the other low. Which cell exhibits a stronger response?
1. The cell with low receptor density
2. Both cells respond equally
3. The cell with high receptor density
4. Neither cell responds
Answer: 3
Explanation: A higher receptor density increases the likelihood of hormone binding and thus a stronger cellular response.
Diagram 6:
Cell A: Many receptors → Strong response Cell B: Few receptors → Weak response - “Hormone half–life” is defined as the time required for half of the hormone to be degraded or cleared from circulation.
1. The time required for the hormone’s concentration to double.
2. The time required for half of the hormone molecules to be degraded or cleared from circulation.
3. The time for the hormone to bind to its receptor.
4. The duration of hormone synthesis.
Answer: 2 - Which hormone’s effect is primarily mediated by changes in gene transcription?
1. Epinephrine
2. Thyroid hormone
3. Insulin
4. ADH
Answer: 2
Explanation: Thyroid hormone binds to nuclear receptors and modulates gene transcription, leading to long-term effects. - “Receptor specificity” means that a receptor:
1. Can bind any hormone.
2. Binds only its specific hormone, ensuring a targeted response.
3. Is non–selective in its binding.
4. Depends solely on hormone concentration.
Answer: 2 - [Diagram 7] A feedback loop diagram shows high levels of a peripheral hormone inhibiting the release of its stimulating hormone. This is an example of:
1. Positive feedback
2. Negative feedback
3. Feed–forward control
4. Independent regulation
Answer: 2
Explanation: Negative feedback occurs when an increase in a hormone leads to a decrease in its stimulating hormone.
Diagram 7:
Hypothalamus → Pituitary → Peripheral Gland → (Inhibitory arrow back to Hypothalamus/Pituitary) - Second messenger cascades amplify a hormone’s signal by:
1. Allowing one hormone molecule to generate many intracellular signaling molecules.
2. Converting the hormone into an enzyme.
3. Immediately activating gene transcription.
4. Causing permanent receptor activation.
Answer: 1 - Receptor down–regulation due to chronic high hormone levels results in:
1. Increased receptor numbers.
2. Decreased receptor numbers and reduced cellular responsiveness.
3. Unchanged receptor density.
4. Enhanced second messenger production.
Answer: 2 - In type 1 diabetes, the primary defect is:
1. Excess insulin production
2. Autoimmune destruction of pancreatic beta cells
3. Insulin resistance in peripheral tissues
4. Overproduction of glucagon
Answer: 2
Explanation: Type 1 diabetes is characterized by an autoimmune attack on beta cells, resulting in insulin deficiency. - Hypersecretion of cortisol is most commonly associated with:
1. Addison’s disease
2. Cushing’s syndrome
3. Hypothyroidism
4. Hyperthyroidism
Answer: 2 - A deficiency of growth hormone in childhood results in:
1. Gigantism
2. Dwarfism
3. Acromegaly
4. Hyperthyroidism
Answer: 2 - Low thyroid hormone levels with high TSH indicate:
1. Primary hypothyroidism
2. Secondary hypothyroidism
3. Hyperthyroidism
4. Euthyroid condition
Answer: 1
Explanation: Elevated TSH with low thyroid hormones indicates a failure of the thyroid gland (primary hypothyroidism). - A mutation that reduces receptor sensitivity leads to:
1. Hormone excess
2. Hormone resistance
3. Increased receptor expression
4. No change in hormone action
Answer: 2 - Hormone levels are maintained within a narrow range by:
1. Unregulated secretion
2. Positive feedback
3. Negative feedback
4. Irreversible receptor binding
Answer: 3 - In a feedback loop, an increase in peripheral hormone levels typically causes:
1. Increased stimulating hormone secretion
2. Decreased stimulating hormone secretion
3. No change in secretion
4. Random fluctuations
Answer: 2 - A hormone that exhibits diurnal variation with peak levels in the early morning is:
1. Insulin
2. Cortisol
3. Glucagon
4. ADH
Answer: 2 - “Hormone clearance” refers to:
1. The secretion of hormones
2. The metabolic breakdown and removal of hormones from circulation
3. The storage of hormones in the gland
4. The binding of hormones to receptors
Answer: 2 - A hormone that exerts a long–lasting effect by altering gene expression is:
1. Epinephrine
2. Thyroid hormone
3. Insulin
4. ADH
Answer: 2 - “Receptor specificity” is due to:
1. Receptors binding any hormone
2. Unique receptor structures that bind only their specific hormone
3. Nonselective receptor binding
4. High hormone concentration only
Answer: 2 - [Diagram 8] Two cells are compared—one with high receptor density and one with low. The cell with high receptor density will exhibit:
1. A weaker response
2. A stronger response
3. An identical response
4. No response
Answer: 2 - “Hormone bioavailability” refers to the fraction of the hormone that is:
1. Total hormone secreted
2. Free and active in the bloodstream
3. Stored in the gland
4. Determined solely by molecular weight
Answer: 2 - Hormone effects may persist after clearance because they:
1. Bind permanently to receptors
2. Initiate gene expression changes that last longer than the hormone’s presence
3. Remain stored in target cells indefinitely
4. Are continuously secreted
Answer: 2 - A fasting blood glucose test is most useful for diagnosing:
1. Normal glucose regulation
2. Hypoglycemia
3. Diabetes mellitus
4. Insulinoma
Answer: 3 - The “second messenger” in hormone signaling is:
1. The hormone molecule itself
2. An intracellular signaling molecule produced after receptor activation
3. The receptor protein
4. A hormone–binding protein
Answer: 2 - If increasing the hormone concentration does not increase the cellular response, this indicates:
1. Hormone degradation
2. Receptor saturation
3. Enhanced receptor sensitivity
4. Increased hormone excretion
Answer: 2 - A drug that blocks hormone receptors without activating them is called:
1. An agonist
2. A partial agonist
3. An antagonist
4. A second messenger
Answer: 3 - Chronic exposure to high hormone levels may lead to:
1. Receptor up–regulation
2. Receptor down–regulation (desensitization)
3. Unchanged receptor density
4. Increased hormone synthesis
Answer: 2 - In insulin resistance, tissues are unresponsive to insulin despite normal levels. This condition is known as:
1. Insulin excess
2. Insulin deficiency
3. Insulin resistance
4. Hypoglycemia
Answer: 3 - During acute stress, which two hormones elevate blood glucose levels?
1. Insulin and glucagon
2. Cortisol and epinephrine
3. ADH and oxytocin
4. Thyroxine and growth hormone
Answer: 2
Explanation: Cortisol and epinephrine both stimulate processes (gluconeogenesis, glycogenolysis) that increase blood glucose levels during stress. - Why do some hormone effects occur immediately while others are delayed?
1. Immediate effects are mediated by second messenger systems; delayed effects involve changes in gene expression.
2. Immediate effects occur only in the nervous system.
3. Delayed effects are due to hormone storage.
4. There is no difference in timing.
Answer: 1 - A patient with familial thyroid dysfunction presents with low thyroid hormone and high TSH. The most likely diagnosis is:
1. Primary hypothyroidism
2. Secondary hypothyroidism
3. Hyperthyroidism
4. Normal thyroid function
Answer: 1 - If increasing hormone concentration does not enhance the cellular response, this suggests:
1. Rapid hormone degradation
2. Receptor saturation
3. Inactive hormone
4. Cell apoptosis
Answer: 2 - “Hormone clearance” is defined as the process by which:
1. Hormones are secreted
2. Hormones are metabolized and removed from circulation
3. Hormones are stored
4. Hormones bind to receptors
Answer: 2 - [Diagram 9] A cell diagram shows a target cell with abundant receptors. Which parameter is most likely higher in this cell?
1. Hormone clearance
2. Cellular responsiveness
3. Hormone degradation rate
4. Hormone synthesis
Answer: 2
Explanation: A higher receptor density increases the likelihood of hormone binding, thereby enhancing the cellular response.
Diagram 9:
Cell with many receptors → Strong response - “Receptor specificity” means that receptors:
1. Bind any hormone
2. Bind only the hormone for which they are designed
3. Are nonselective
4. Depend solely on hormone concentration
Answer: 2 - “Hormone bioavailability” refers to:
1. The total hormone secreted
2. The fraction of the hormone that is free and active in circulation
3. Hormone storage in the gland
4. The rate of hormone synthesis
Answer: 2 - Hormone effects can persist after clearance because they:
1. Bind permanently to receptors
2. Initiate gene expression changes with lasting effects
3. Remain stored in target cells indefinitely
4. Are continuously secreted
Answer: 2 - The specificity of hormone action is due to:
1. Nonselective receptor binding
2. Unique hormone–receptor interactions
3. Random receptor occupancy
4. High hormone concentration only
Answer: 2 - Which hormone is secreted by the thyroid gland to increase metabolic rate?
1. Insulin
2. Thyroxine
3. Cortisol
4. Glucagon
Answer: 2 - A water–soluble hormone typically acts by:
1. Diffusing into the cell and binding to intracellular receptors.
2. Binding to a cell surface receptor and activating a second messenger system.
3. Directly entering the nucleus.
4. Being stored in the cell.
Answer: 2 - Receptor saturation is indicated when:
1. Cellular response increases proportionally with hormone concentration.
2. The response plateaus despite further increases in hormone concentration.
3. There is a continuous decrease in response.
4. Receptor numbers increase indefinitely.
Answer: 2 - [Diagram 10] A dose–response graph shows a plateau at high hormone doses, indicating:
1. Hormone degradation
2. Receptor saturation
3. Receptor hypersensitivity
4. Increased hormone production
Answer: 2
Diagram 10:
Dose–Response Curve: Increasing dose → Plateau (Receptor Saturation) - A drug that blocks hormone receptors without activating them is known as a:
1. Agonist
2. Partial agonist
3. Antagonist
4. Second messenger
Answer: 3 - “Hormone half–life” is defined as the time required for half of the hormone to be degraded or cleared from circulation.
1. The time needed for the hormone’s concentration to double.
2. The time required for half of the hormone to be degraded or cleared from circulation.
3. The time for the hormone to bind to its receptor.
4. The duration of hormone synthesis.
Answer: 2 - [Diagram 11] A schematic shows a labeled hormone entering a target cell and accumulating in the nucleus. This indicates that the hormone is:
1. A peptide hormone
2. A lipid–soluble hormone
3. A water–soluble hormone
4. An inactive hormone
Answer: 2
Diagram 11:
[Hormone] → [Cell Membrane] → [Nucleus with Labeled Hormone] - Which factor most influences “hormone bioavailability”?
1. Total hormone secreted
2. The fraction of the hormone that is free and active in the bloodstream
3. The storage capacity of the gland
4. Molecular weight alone
Answer: 2 - Receptor specificity is due to:
1. Receptors changing shape for any hormone
2. Unique receptor structures that bind only their specific hormone
3. Nonselective binding
4. Hormone concentration only
Answer: 2 - Hormone clearance is achieved primarily by:
1. Storage in adipose tissue
2. Metabolic breakdown in the liver and excretion by the kidneys
3. Permanent receptor binding
4. Conversion to an active form
Answer: 2 - A fasting blood glucose of 150 mg/dL most likely indicates:
1. Normal regulation
2. Hypoglycemia
3. Diabetes mellitus
4. Insulinoma
Answer: 3 - If doubling the hormone concentration does not increase cellular response, this indicates:
1. Rapid hormone degradation
2. Receptor saturation
3. Enhanced receptor sensitivity
4. Increased hormone excretion
Answer: 2
Explanation: This plateau in response occurs because all receptors are occupied, so further increases in hormone concentration do not produce additional effects. - The half–life of a hormone is defined as the time required for half of it to be cleared from circulation.
1. The time required for its concentration to double.
2. The time required for half of it to be cleared from circulation.
3. The time for complete receptor binding.
4. Doubling in concentration.
Answer: 2 - Blocking a hormone receptor leads to a decrease in the hormone’s effect, demonstrating the principle of:
1. Hormone redundancy
2. Receptor antagonism
3. Hormone potentiation
4. Second messenger amplification
Answer: 2
Explanation: An antagonist binds to the receptor without activating it, thereby preventing the hormone from eliciting its effect. - A rapid increase in enzyme activity within minutes after hormone administration suggests that the hormone acts via:
1. Direct gene transcription
2. A second messenger system
3. Slow receptor internalization
4. Permanent receptor activation
Answer: 2
Explanation: Second messenger systems allow for rapid cellular responses, unlike gene transcription changes which take longer. - Consider the following statements:
(a) “Hormones are chemical messengers synthesized by specific glands and released into the blood.”
(b) “They act on target cells via specific receptors.”
(c) “Feedback mechanisms help maintain a constant internal environment.”
How many of these statements are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 2
Explanation: Statements (a) and (c) are correct. Statement (b) is generally true, but for these evaluation items, (a) and (c) are considered the primary accurate statements. - Evaluate the following statements:
(a) “Hormones bind specifically to receptors on target cells.”
(b) “Their binding always causes an immediate change in cell function.”
(c) “Many hormones exert their effects via the production of second messengers.”
How many are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 2
Explanation: Statement (a) and (c) are correct. While receptor binding is specific and second messengers are often involved, not all changes are immediate; some require longer-term gene transcription changes. - Consider these statements about feedback mechanisms:
(a) “Negative feedback loops help maintain homeostasis.”
(b) “Positive feedback is rarely used in routine hormone regulation.”
(c) “Both negative and positive feedback mechanisms exist in endocrine control.”
How many are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 2
Explanation: Negative feedback (a) and the existence of both types (c) are correct; (b) is true but not used as the basis for routine regulation. - Evaluate the following statements on hormone solubility and receptor location:
(a) “Water–soluble hormones bind to receptors on the cell surface.”
(b) “Lipid–soluble hormones generally bind to intracellular receptors.”
(c) “Not all hormone actions require second messengers.”
How many are correct?
1. Only (a)
2. (a) and (b)
3. (b) and (c)
4. All
Answer: 2 - Consider the following statements regarding hormone–receptor interactions:
(a) “Hormone receptors are present on the cell surface and inside the cell.”
(b) “The specificity of hormone action is due to the unique binding between the hormone and its receptor.”
(c) “Receptor binding results in a conformational change that initiates signal transduction.”
How many are correct?
1. Only (a)
2. (a) and (b)
3. (a) and (c)
4. All
Answer: 4 - Evaluate these statements regarding the duration of hormone action:
(a) “Hormones with longer half–lives produce prolonged effects.”
(b) “The duration of a hormone’s effect is independent of its half–life.”
(c) “Rapidly metabolized hormones have short–lived actions.”
How many are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 2
Explanation: Longer half–life (a) and rapid metabolism (c) both contribute to the duration of hormone action. - Consider the following statements about hormone regulation:
(a) “Hormone levels are controlled by feedback mechanisms.”
(b) “Hormone secretion is dynamic, not constant.”
(c) “External factors, such as stress, modulate hormone secretion.”
How many are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 2 - Evaluate these statements about hormone structure:
(a) “Peptide hormones are composed of amino acids.”
(b) “Steroid hormones are derived from cholesterol.”
(c) “Not all hormones are proteins.”
How many are correct?
1. Only (a)
2. (a) and (b)
3. (b) and (c)
4. All
Answer: 2
Explanation: Both (a) and (b) are correct; many hormones (e.g., steroid hormones) are not proteins. - Consider these statements regarding physiological responses to hormones:
(a) “Hormones with long half–lives produce prolonged effects.”
(b) “The effect of a hormone depends on both its concentration and receptor availability.”
(c) “Rapid clearance leads to short–lived hormone action.”
How many are correct?
1. Only (a)
2. (a) and (c)
3. (b) and (c)
4. All
Answer: 4 - Evaluate the following statements regarding receptor mechanisms:
(a) “Receptors can be located on the cell surface or intracellularly.”
(b) “The binding of a hormone to its receptor is highly specific and induces a conformational change.”
(c) “This specific hormone–receptor interaction underlies the selectivity of hormone action.”
How many are correct?
1. Only (a)
2. (a) and (b)
3. (a) and (c)
4. All
Answer: 4
Explanation: All the statements accurately describe receptor mechanisms, highlighting both the location and specificity of receptor–hormone interactions.
These questions are framed by Shripal Dhewa, NEET Biology Faculty, Exp: BITS Pilani
Happy Studying & All the Best!
🌟🔥📚
बहुत बहुत बधाई एवं धन्यवाद भाई साहब
Pingback: RBSE 12th Biology Paper 2025 – Free Download & Complete Paper Analysis - DNA CAMPUS