Question

Secondary growth does not take place in majority of the living pteridophytes,----------------------- being an exception.

• A. Adiantum
• B. Equiselum
• C. Isoetus
• D. Pterdinum

Answer 1

Answer:

C. Isoetus

Isoetes, also known as quillworts, is the only living genus of pteridophytes that exhibits secondary growth. Secondary growth is a process that causes the thickening of stems and roots due to cell division in the lateral meristems. It is a characteristic feature of dicotyledons and gymnosperms, but is rare in living pteridophytes. Isoetes is the exception, and is a genus of lycopods that grow in aquatic habitats or marshes.