Which of the following is the simplest living organism?

A. Paramecium
B. Virus
C. Amoeba
D. Chlamydomonas

Correct Answer:

Option B – Virus

Explanation

If viruses, prions, satellites, nanobes, nanobacteria (non-free-living sub-bacterial organisms) are excluded, the simplest free-living organism known is Mycoplasma genitalium, with a genome of only 580,000 base pairs and 482 protein-coding genes.