Question

Pits are

• A. Depressions in primary walls
• B. Depressions in secondary walls
• C. Both A and B
• D. Plasmodesmal connections.

Answer 1

Answer: (B)

Depressions in secondary walls

• Lignin is an important element in the secondary cell wall of plants.
• The lignified depressions in the secondary cell wall form a Pit.
• These are thin regions in the secondary cell wall in plants through which the adjacent cells can communicate or exchange fluid through them (vessels and tracheids of xylem)
  
• They are the characteristic structures of cell walls with secondary layers.
  
• So, the correct answer is 'Depressions in secondary walls'.