Dangerous organisms that can grow in a variety of environments and are capable of producing toxic substances are known as:

Bacteria

Explanation:

Bacteria are the dangerous organisms that can grow in a many different environments and are capable of producing toxic substances which can harm other organisms. This bacteria has the ability to survive in the most extreme environment present near the volcanoes. There are about 30,000 species of bacteria that can live in a variety of environments. There are also some bacteria that is beneficial to humans, animals and plants but they are less in number.

thats not even an aswer choice