NEET Biology: Mechanism of hormone action (Elementary Idea) Practice Questions
15 free multiple-choice questions on Mechanism of hormone action (Elementary Idea) (Chemical Coordination and Regulation) for NEET Biology, each with the correct answer and a step-by-step explanation. Attempt a question, then reveal the solution to check your reasoning.
Practice thousands more NEET questions in the app →Q1. The mechanism by which a hormone exerts its effect is dependent on its specific chemical structure. This dependency implies that hormones must interact with specific molecular structures to elicit a response.
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Correct answer: C — Specificity
Hormones exhibit high specificity; they only interact with receptors that possess the complementary shape for binding.
Q2. In the context of hormone action, what term describes the general mechanism where a signal molecule (hormone) triggers a reaction in a distant cell?
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Correct answer: C — Paracrine signaling
Paracrine signaling involves signaling molecules (hormones) acting locally on nearby cells, while endocrine signaling involves signaling over long distances via the blood.
Q3. Hormones act as chemical messengers. What is the term for the specific receptor protein on the cell surface or inside the cell that binds the hormone?
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Correct answer: A — Membrane receptor
Receptors are specific proteins designed to recognize and bind to the corresponding hormone, initiating the signal cascade.
Q4. The binding of a hormone to its receptor primarily leads to which of the following events?
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Correct answer: A — Activation of secondary messengers
Hormone binding to a receptor causes a conformational change, which triggers a chain reaction (signal transduction), often involving secondary messengers, to elicit the cellular response.
Q5. A mechanism where the output of a system regulates its own input is known as:
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Correct answer: A — Negative feedback
Negative feedback is a key regulatory mechanism where the final output of a system acts to reduce the initial stimulus, maintaining homeostasis.
Q6. Which mode of hormone action involves the release of hormones into the bloodstream to reach distant target organs?
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Correct answer: D — Endocrine action
Endocrine action is the mechanism where hormones are secreted into the circulatory system (bloodstream) and travel to distant target cells.
Q7. Hormones exert their effect by binding to specific sites on target cells. What is the primary site where hormones typically bind to initiate a response?
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Correct answer: A — Nucleus
Hormone receptors are usually located on the surface (plasma membrane) or inside the cell (cytoplasm/nucleus) of the target cell to detect the hormone signal.
Q8. Which term describes the process by which a hormone signal travels from the receptor to the cell nucleus to influence gene expression?
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Correct answer: B — Signal transduction
Signal transduction is the entire process where the signal received at the receptor is converted into a specific cellular response, often involving protein interactions leading to changes in gene expression.
Q9. Which of the following processes describes the binding of a hormone to its specific receptor site on a target cell?
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Correct answer: B — Signal reception
The binding of a hormone to its specific receptor is the initial and defining step in the mechanism of action, known as signal reception.
Q10. If a hormone binds to a receptor, what is the next stage in the mechanism of action?
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Correct answer: A — Signal transduction occurs
After binding, the signal must be transmitted inside the cell via signal transduction pathways before the final effect is manifested.
Q11. The general idea of hormone action involves a series of steps starting from:
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Correct answer: B — Receptor activation and signal transduction
The entire mechanism of hormone action begins with the external signal (hormone binding) leading to the internal response (signal transduction) inside the cell.
Q12. The primary role of a hormone in the body is to communicate instructions to specific target cells. This communication process involves the hormone binding to a specific location on the target cell. What is the term for this binding site?
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Correct answer: A — Receptor
The receptor is the specific site (usually a protein) on the target cell where the hormone binds, initiating the response.
Q13. Which structure is primarily responsible for sensing the presence of a specific hormone in the body?
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Correct answer: D — Receptor
Receptors are specialized protein structures (often embedded in the cell membrane or inside the cell) that bind to specific hormones and initiate a cellular response.
Q14. A negative feedback mechanism in hormone regulation primarily functions to:
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Correct answer: D — Reduce the initial stimulus
Negative feedback loops work to counteract the initial change, typically by reducing or inhibiting the production or release of the hormone, thereby stabilizing the system.
Q15. Which of the following is the primary site where a hormone typically binds to initiate a response in a target cell?
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Correct answer: B — Receptor
Hormones act by binding to specific receptor molecules located on the cell surface or inside the cell, initiating the signaling cascade.
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