Plastics are made from non-renewable and non-biodegradable materials and are difficult to convert to environmentally friendly substances. As a result, the organisms and their habitat are facing danger that might lead to destruction, scarcity of food resources, and even death.
Darwin noticed that there were different kinds of the same species. For example, he studied four different kinds of finches. Each one had a different beak and are different kinds of food. This was the first time genetic diversity had been so obvious to humans.
Answer: germ theory
Explanation: Germ theory of disease is a theory in biology. It says that small organisms (called germs), also known as microbes, cause diseases. Most, but not all diseases are infectious diseases. The germ theory states that small organisms cause a reaction in the body of those who are infected. The body's reaction to infection is called a disease.
Reference: Wikipedia