Q.19 Match List-I with List-II

Choose the correct answer from the options given below:

1. (A) – (I), (B) – (III), (C) – (II), (D) – (IV)
2. (A) – (II), (B) – (III), (C) – (I), (D) – (IV)
3. (A) – (II), (B) – (III), (C) – (IV), (D) – (I)

4. • Option 1: (A)–(I), (B)–(III), (C)–(II), (D)–(IV): Wrong; progesterone isn’t from adrenal cortex (that’s aldosterone), and estrone isn’t from corpus luteum.​

   • Option 2: (A)–(II), (B)–(III), (C)–(I), (D)–(IV): Wrong; estrone isn’t from adrenal cortex (mineralocorticoids like aldosterone are).​

   • Option 3: (A)–(II), (B)–(III), (C)–(IV), (D)–(I): Correct; matches all primary synthesis sites as explained.​

   • Option 4: (A)–(I), (B)–(III), (C)–(IV), (D)–(II): Wrong; progesterone isn’t from adrenal cortex, and aldosterone isn’t from corpus luteum.​(A) – (I), (B) – (III), (C) – (IV), (D) – (II)

     Progesterone is mainly produced by the corpus luteum, testosterone by the testes, estrone by the ovaries, and aldosterone by the adrenal cortex, making option 3 the correct match.​

     Correct Matching

     • (A) Progesterone → (II) Corpus luteum: After ovulation, the corpus luteum forms in the ovary and secretes progesterone to prepare the uterus for pregnancy.

     • (B) Testosterone → (III) Testis: Leydig cells in the testes produce testosterone, the primary male sex hormone regulating reproductive functions.​

     • (C) Estrone → (IV) Ovary: Estrone, an estrogen, is synthesized mainly in ovarian follicles, especially post-menopause.​

     • (D) Aldosterone → (I) Adrenal cortex: Zona glomerulosa cells in the adrenal cortex produce aldosterone to regulate sodium and potassium balance.​

     Option Analysis

   The hormone site of synthesis matching question tests key endocrinology facts for GATE Life Sciences and NEET exams. Understanding where progesterone, testosterone, estrone, and aldosterone are produced helps master reproductive and adrenal physiology. This guide breaks down the correct matches, explains errors in other options, and boosts your competitive exam prep.

   Primary Sites Explained

   Progesterone’s main site of synthesis is the corpus luteum post-ovulation, supporting pregnancy by thickening the endometrium. Testosterone originates from testis Leydig cells, driving male secondary sex characteristics. Estrone, an estrogen variant, comes from the ovary, particularly in granulosa cells. Aldosterone is synthesized in the adrenal cortex’s zona glomerulosa for electrolyte balance.

   Why Option 3 Wins

   Only (A)–(II), (B)–(III), (C)–(IV), (D)–(I) aligns perfectly with physiological sources, as confirmed in standard biology resources. Other options mix up gonadal vs. adrenal origins, common pitfalls in exams.​

   Exam Tips for GATE/NEET

   • Memorize: Corpus luteum for progesterone; testis for testosterone; ovary for estrogens like estrone; adrenal cortex for aldosterone.​

   • Practice PYQs on hormone site of synthesis to score high in biochemistry sections.