It is how plants turn sunlight, water, and carbon dioxide into food and oxygen
One-celled organisms involved in fermentation, putrefaction, infectious diseases, or nitrogen fixation.
An organism that lives on or in a different kind of organism (the host) from which it gets some or all of its nourishment. Parasites are generally harmful to their hosts, although the damage they do ranges widely from minor inconvenience to debilitating or fatal disease.
refusal to give in or to something that slows down or prevents something
A force or influence, or an insect that is a carrier of a disease-producing organism
A person, thing or company that delivers something
Spreading of disease from one individual to another by direct or indirect contact
A physical or chemical agent that changes genetic material
The use of living organisms by humans