Question

Leaf primordium grows into adult lamina by means of

• A. Marginal meristem
• B. Lateral meristem
• C. First apical and then marginal meristem
• D. Apical meristem

Answer 1

The correct option is D Apical meristem

• The apical meristematic tissues are present at the shoot tips and root tips in plants.
  
• They are actively dividing metabolic cells which continuously divided to form three distinct layer at the shoot and root tip.
  
• Leaves are derived from the shoot apical meristem or SAM.
• The SAM swells up to form the undifferentiated leaf primordium which divides into two systems that develop leaf blades and leaf sheaths.
  
• The leaf blades grow mainly due to cell elongation.
• The flattened blade is derived from the marginal meristem present at the margins of the leaf.
• The lateral meristems that increase the girth of the plant are termed a lateral meristem and are not involved in leaf formation.
  
• So, the correct answer is 'First apical and then marginal meristem'