You find a previously unknown single-celled organism in a water sample.While studying it,you find that the organism is photosynthetic and has a cell membrane surrounded by a layer of peptidoglycan (carbohydrates linked to peptides).The organism contains DNA and RNA,but you see no nuclear membrane.This organism most likely belongs to which group?
A) Eukaryotes
B) Protists
C) Bacteria
D) Archaea
E) Animals

Question

Quizplus · Accepted Answer

The presence of peptidoglycan indicates that the organism is a bacteria. The absence of a nuclear membrane suggests that it is a prokaryote, and not a eukaryote which possess a nucleus surrounded by a membrane. It cannot be an animal as animals are multicellular. While protists can be either prokaryotic or eukaryotic, the presence of peptidoglycan suggests that it is a prokaryotic bacterium. Archaea may have cell walls, but these are composed of different materials than peptidoglycan.

You Find a Previously Unknown Single-Celled Organism in a Water