Question

In which stem, lateral meristem is absent ?

• A. Palm
• B. Bougainvillea
• C. Boerhaavia
• D. Mirabilis

Answer 1

The correct option is A Palm

Secondary growth refers to the growth that results from cell division in the cambia or lateral meristems and that causes the stems and roots to thicken, while primary growth is growth that occurs as a result of cell division at the tips of stems and roots, causing them to elongate and gives rise to primary tissue. Secondary growth occurs in most seed plants, but monocots usually lack secondary growth due to absence of lateral meristem. Most monocots either have no secondary growth or else anomalous secondary growth of some type.
For example, palm trees increase their trunk diameter due to division and enlargement of parenchyma cells, which is termed diffuse secondary growth. Bougainvillea, Boerhaavia and Mirabilis has lateral meristem in their stems.
Therefore, the correct answer is option A.