What is the approximate number of species which have been identified and listed till now?

Explanation

**Step-by-Step Text Solution:**

1. **Understanding the Question**: The question asks for the approximate number of species that have been identified and listed so far. This includes both plants and animals.

2. **Species Classification**: In biological classification, species is the lowest category. It is essential to understand that species classification helps in identifying the diversity of life forms based on their similarities and differences.

3. **Total Number of Species**: According to scientific estimates, the total number of species that have been identified and listed is approximately 8.7 million. This figure encompasses a wide range of organisms, including both flora (plants) and fauna (animals).

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