Bacteria, Viruses, Protists and Fungi
Science

A thick-walled structure that protects the DNA of bacteria, this protects the DNA in unfavorable conditions
Endospore
A thick-walled structure that protects the DNA of bacteria, this protects the DNA in unfavorable conditions. Endospore. An endospore is a tough, dormant form that some bacteria can take to survive harsh environments.

An organism that lives in or on another organism, harming it in the process, like lice or ticks
Parasite
An organism that lives in or on another organism, harming it in the process, like lice or ticks. Parasite. In simple terms, a parasite is a creature that depends on another living being for survival while causing it harm.