Difficulty: Easy
Correct Answer: 5
Explanation:
Introduction:Steroid hormones are cholesterol-derived signaling molecules that regulate metabolism, salt balance, inflammation, and reproduction. This question asks for the standard number of broad classes used in human physiology and biochemistry texts.
Given Data / Assumptions:
Concept / Approach:The commonly cited five classes are: glucocorticoids (e.g., cortisol), mineralocorticoids (e.g., aldosterone), androgens (e.g., testosterone), estrogens (e.g., estradiol), and progestogens (e.g., progesterone). Some texts also discuss secosteroids (vitamin D) separately, but the classic endocrine classification lists five groups.
Step-by-Step Solution:
1) Adrenal cortex: glucocorticoids regulate glucose metabolism and stress.2) Adrenal cortex: mineralocorticoids control sodium/potassium and blood pressure.3) Gonads: androgens drive male secondary sex characteristics.4) Gonads/placenta: estrogens drive female reproductive physiology.5) Gonads/placenta: progestogens support pregnancy and cycle regulation.Verification / Alternative check:Endocrinology references uniformly present these five categories; clinical assays and receptor families (GR, MR, AR, ER, PR) map onto them.
Why Other Options Are Wrong:
Common Pitfalls:Confusing structural classes with tissue sources or receptor subtypes. The accepted introductory answer is five classes.
Final Answer:5.
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