What are the three major threat categories of species ? Describe with examples.

What are three major threat categories of species? Describe with examples.

What are the three main categories of variations?

What are endangered species? Explain with examples.

What is hierarchy of categories ? Describe the same.

What are the two basic categories of ecosystem? Give example.

Reason : This is not a category of species in red list whereas the other are categories of species in the red list.

What are Pioneer species? Give examples.