Question

What is the difference between primary and secondary protonema?

Answer 1

Primary protonema:

Primary protonema is the stem of spores.

Secondary protonema:

The branches and leaves from the spore stem are secondary protonema.

Sl. No.	Primary protonema	Secondary protonema
1	The spores of mosses give rise to primary protonema.	Secondary protonema is leaves and rhizoids.
2	The primary protonema is formed after germination. E.g. moss	Secondary protonema helps in the development of all gametophyte cells.