This is a poisonous substance that is produced by living cells or organisms and is capable of causing disease when introduced into living tissues

This substance is termed as a toxin.

Explanation:

Toxin can be described as a poisonous substance that is made by living organisms and can also be produced artificially. Inside the living cells, toxins are usually produced as harmful proteins. Toxins which are produced from fungi are termed as mycotoxins, those produced by plants are termed as phytotoxins and those produced by animals are termed as zootoxins. Apart from these, microorganisms like bacteria make a wide number of toxins. Some algae species are also known to produce toxins which can be very harmful to humans.