Transformation of meristematic cells into specific permanent tissues occurs by the process of
- (a)Cell differentiation.
- (b)Cell division.
- (c)Cell multiplication.
- (d)Cell regeneration.
Correct — A, Cell differentiation. Meristematic cells are unspecialised cells that keep dividing. When their daughter cells stop dividing and take on a particular structure and function — becoming xylem, phloem, parenchyma and so on — that process of gaining specialised, permanent features is called differentiation. So meristematic tissue becomes permanent tissue by differentiation.
- (b)Cell division. — Division only increases the number of cells; the meristem's dividing keeps producing new cells but does not by itself make them specialised permanent tissue.
- (c)Cell multiplication. — This is just another way of describing an increase in cell number, not the acquisition of a specialised, permanent form.
- (d)Cell regeneration. — Regeneration is the replacement or regrowth of lost or damaged parts, not the routine conversion of meristematic cells into permanent tissue.
Plant growth starts in meristems — regions of actively dividing, unspecialised cells (apical meristems at root and shoot tips, lateral meristems like cambium). The cells they produce gradually lose the ability to divide and develop specific shapes, walls and contents to perform particular jobs. This maturation into specialised permanent tissue is differentiation.
The distractors all describe increases in cell number, which is tempting because meristems clearly do divide a lot. The distinction being tested is between making more cells (division/multiplication) and making cells specialised (differentiation). Only differentiation turns dividing meristem cells into fixed permanent tissue.
- Meristematic tissue consists of unspecialised cells that divide actively.
- Differentiation is the process by which these cells become specialised permanent tissue.
- Permanent tissues include simple (parenchyma, collenchyma, sclerenchyma) and complex (xylem, phloem) tissues.
- Apical meristems drive growth in length; lateral meristems (cambium) drive growth in girth.
- Choosing 'cell division' — division increases number, differentiation adds specialisation.
- Confusing differentiation with regeneration (repair of lost parts).
Asked as 'the process that converts meristematic cells into permanent tissue' or by defining differentiation versus division.
No directly related past PYQ was found.
- practice — not a real PYQ
Which of the following is a complex permanent tissue in plants?
- (a)Parenchyma
- (b)Collenchyma
- (c)Xylem
- (d)Meristem
Answer(c) Xylem — a complex permanent tissue that conducts water and minerals.
- practice — not a real PYQ
Growth in the length of a plant is brought about mainly by
- (a)lateral meristem
- (b)apical meristem
- (c)permanent tissue
- (d)cork cambium
Answer(b) apical meristem — found at the tips of roots and shoots.