(A) A-I, B-IV, C-II, D-III
(B) A-IV, B-II, C-III, D-I
(C) A-III, B-IV, C-I, D-II
(D) A-II, B-III, C-I, D-IV

The correct answer is option (C): A-III, B-IV, C-I, D-II.

Histogen Theory Matches

Plerome is the innermost histogen layer, precursor of the central vascular cylinder (stele). Histogen refers to Hanstein’s theory concept of distinct tissue precursor regions (three layers: dermatogen, periblem, plerome). Dermatogen is the outermost layer, precursor of epidermis. Periblem is the middle layer, precursor of cortex.

Option Analysis

• Option (A): A-I (wrong; I is epidermis), B-IV (correct), C-II (wrong; II is cortex), D-III (wrong; III is vascular).

• Option (B): A-IV (wrong; IV is histogen theory), B-II (wrong), C-III (wrong), D-I (wrong).​

• Option (C): A-III (plerome-vascular), B-IV (histogen-theory), C-I (dermatogen-epidermis), D-II (periblem-cortex). All correct.

• Option (D): A-II (wrong), B-III (wrong), C-I (correct), D-IV (wrong).​

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Plerome, histogen, dermatogen, and periblem are key terms in plant anatomy from Hanstein’s histogen theory, vital for life sciences exams. This article solves Q.75 matching question with precise precursor functions.

Histogen Theory Basics

Hanstein proposed three meristematic layers (histogens) in shoot/root apices forming primary tissues.​

• Dermatogen: Outermost, gives epidermis (protection).​

• Periblem: Middle, forms cortex (storage, support).​

• Plerome: Innermost, yields vascular cylinder/stele (conduction).​

• Histogen: Overall precursor zones concept.​

Correct Matching (Option C)

A-III (Plerome-vascular), B-IV (Histogen-tissues), C-I (Dermatogen-epidermis), D-II (Periblem-cortex).

Why Other Options Incorrect

Option A/D misassign dermatogen/periblem; vascular is plerome only. Option B confuses histogen role.