NDA (I) 2025 General Ability Test · Question 108 of 150

Correct — A, Lateral meristem. Cambium is a ring of actively dividing cells that lies along the sides of stems and roots, between the wood (xylem) and bark (phloem). Because it sits on the lateral (side) region and adds cells outward and inward, it thickens the plant — this is secondary growth, the increase in girth. A dividing tissue positioned laterally and causing thickening is, by definition, a lateral meristem.

• (b)Apical meristem — Apical meristem sits at the growing tips of roots and shoots and causes the plant to grow in length (primary growth), not in girth. Cambium is not at the tips, so this is wrong.
• (c)Intercalary meristem — Intercalary meristem lies at the bases of leaves or internodes (as in grasses) and also adds length. Cambium is not intercalary — it runs along the sides and adds thickness.
• (d)Permanent tissue — Permanent tissues are made of cells that have stopped dividing and taken on a fixed role. Cambium is the opposite — a meristem whose cells keep dividing, so it is not a permanent tissue.

Meristems are regions of continuously dividing cells that let plants grow. They come in three kinds: apical (at root and shoot tips, giving growth in length), intercalary (at the base of leaves/internodes, also adding length) and lateral (along the sides, adding girth). Cambium is a lateral meristem responsible for secondary growth.

Ask where the tissue sits and what growth it produces. Cambium runs lengthwise along the sides of the stem and root and makes the plant thicker — that is the hallmark of a lateral meristem. Apical and intercalary meristems add length, and permanent tissue does not divide at all, so each of those is ruled out.

• Cambium is a lateral meristem causing secondary growth (increase in girth).
• Vascular cambium adds secondary xylem inward and secondary phloem outward.
• Apical meristems at root/shoot tips give primary growth (increase in length).
• Intercalary meristems occur at leaf/internode bases, notably in grasses.

• Linking cambium to 'tips' and picking apical — cambium is lateral, along the sides.
• Calling cambium a permanent tissue — it is a dividing meristem.

Plant-tissue questions match a named tissue to its type or its growth role — learn each meristem's position and the growth it produces.

No directly related past PYQ was found.

• practice — not a real PYQ

  Growth in the length of a plant is brought about mainly by the

  • (a)Lateral meristem
  • (b)Apical meristem
  • (c)Cork cambium
  • (d)Permanent tissue

  Answer(b) Apical meristem — at root and shoot tips, giving primary growth in length.

• practice — not a real PYQ

  Secondary growth (increase in girth) in a dicot stem is caused by the

  • (a)Vascular cambium
  • (b)Apical meristem
  • (c)Intercalary meristem
  • (d)Epidermis

  Answer(a) Vascular cambium — a lateral meristem that adds new xylem and phloem.