Thallus:

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.

ADVERTISEMENTS:

4. Gametes are mostly biflagelleted.

5. It may be unicellular or multicellular.

Prothallus:

1. It is a small, thallus-like green, flat and heart-shaped structure found in ferns.

ADVERTISEMENTS:

2. It is a gametophyte and reproduces only sexually.

3. Prothallus contains antheridium and archegonium.

4. Gametes are multiflagllated.

5. It is multicellular.