Question

Periderm is a protective tissue found in stems and roots of gymnosperm and woody dicotyledons. It contributes to the increased thickness by secondary growth. Match the peridermal components given in Group I with the cell/tissue types given in Group II. 

• A. P-4; Q-3; R-1; S-2
• B. P-3; Q-2; R-4; S-1
• C. P-2; Q-1; R-3; S-4
• D. P-4; Q-1; R-3; S-2

Hint:

Remember the sequence: {Phellogen} (cork cambium) forms {Phellem} (cork) outward and {Phelloderm} inward. Phelloids are specialized sclereid-like cells in periderm.

Answer 1

The Correct Option is B

Step 1: Phelloids. These are sclereid-like cells, thick-walled and similar to cork cells. Hence (P) $⇒$ (3).
Step 2: Phellogen. This is the cork cambium, a secondary lateral meristem. Hence (Q) $⇒$ (2).
Step 3: Phellem. This is the cork layer, made of dead suberized cells. Hence (R) $⇒$ (4).
Step 4: Phelloderm. This is the living tissue resembling cortical parenchyma formed inward by phellogen. Hence (S) $⇒$ (1).
Thus, the correct matching is: \[ P-3;\ Q-2;\ R-4;\ S-1 \]