Differentiate between the following.
Prothalius and protonema

Explanation

To differentiate between Prothallus and Protonema, we can follow these steps:

### Step 1: Definition
- **Protonema**: It is the initial stage of development in mosses and liverworts. It is typically a thread-like structure that develops from the spore after germination.
- **Prothallus**: It is the gametophytic stage of ferns (pteridophytes). It is a heart-shaped structure that develops from the spore and is responsible for producing gametes.

### Step 2: Structure
- **Protonema**: The structure is filamentous and resembles a green thread or filament. It is composed of a network of cells.
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