What is the term for the type of spore formed when a bacterium produces a thick internal wall that encloses its DNA and a portion of its cytoplasm?

• A. Endospore
• B. Eukaryote
• C. Prokaryote
• D. Retrovirus

Answer: (A)

Endospores are a dormant, highly resistant structure formed by some bacteria when conditions are harsh. During formation, the DNA is preserved inside a thick internal wall along with a portion of cytoplasm, and a tough protective coat is built around it. This allows the bacterium to survive extreme heat, desiccation, and other stresses until conditions improve and the endospore can germinate back into a normal, active cell. This concept is distinct from eukaryotes, which are cells with a nucleus; from prokaryotes in general, which are single-celled organisms lacking a nucleus but don’t form these thick-walled dormant structures; and from retroviruses, which are RNA viruses that infect cells. The term for this spore-forming structure is endospore.