A group of scientists sequence and identify various regions of an organism's genome and find that 92% of the genome (a circular chromosome and a plasmid) is comprised of protein-coding genes. The organism is most likely a?

Bacteria

Explanation:

Bacteria contain all their DNA in a single circular chromosome. Bacteria also contain other smaller circular DNA molecules called plasmids, which can be obtained from other bacteria - through a process called conjugation - or from the environment.

Bacterial genomes are smaller than eukaryotic genomes, and unlike eukaryotes, most of the bacterial genome is coding. In most species of bacteria there is no non-coding regions between exons.