Who classified tissues for the first time? How many types of tissue system are known?

Explanation

### Step-by-Step Solution:

1. **Identify the Scientist**: The first step is to recognize who classified tissues for the first time. The scientist credited with this classification is a German scientist named **Sack**.

2. **Year of Classification**: It is important to note the year when this classification was attempted, which was **1875**.

3. **Basis of Classification**: Sack classified tissues based on their **position and morphology**. This means he looked at where the tissues were located in the plant and their structural characteristics.

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