1. When the plant body is not differentiated into root, stem and leaves, it is called thallus. It is found in algae.
2. It is a gametophyte but reproduces both asexually and sexually.
3. Specialised sex organs, such as antheridium and archegonium are not formed.
4. Gametes are mostly biflagelleted.
5. It may be unicellular or multicellular.
1. It is a small, thallus-like green, flat and heart-shaped structure found in ferns.
2. It is a gametophyte and reproduces only sexually.
3. Prothallus contains antheridium and archegonium.
4. Gametes are multiflagllated.
5. It is multicellular.