Researchers are studying a single-celled pathogen. Which experimental method would be LEAST effective for determining whether the pathogen is prokaryotic or eukaryotic?

Question

Researchers are studying a single-celled pathogen.  Which experimental method would be LEAST effective for determining whether the pathogen is prokaryotic or eukaryotic?

Quizplus · Accepted Answer

11ecba2d_100f_fa92_a3bf_a7690b936226_MD0008_00 Cells can be classified as either prokaryotic or eukaryotic based on specific cellular characteristics. Prokaryotes and eukaryotes differ in various traits, such as the number of origins of replication, presence of membrane-bound organelles, and genome location and morphology. In the given scenario, scientists must identify a characteristic unique to either prokaryotes or eukaryotes that will allow them to classify the pathogen into one of the two groups. However, glycolysis is a process that occurs in the cytoplasm of both prokaryotic and eukaryotic cells, and results in the synthesis of pyruvate. Therefore, the presence of pyruvate in the pathogen's cytoplasm would not be a defining characteristic that would help determine whether it is prokaryotic or eukaryotic. (Choice A) In both prokaryotes and eukaryotes, DNA replication is initiated at the origin of replication. Prokaryotes have a single circular chromosome with a single origin of replication whereas eukaryotes have linear chromosomes with multiple origins of replication. By assessing the number of replication origins, researchers can determine whether a cell is prokaryotic or eukaryotic. (Choice B) Mitochondria are the sites of aerobic respiration in eukaryotic cells but are absent in prokaryotic cells. An antimitochondrial antibody will bind only in the presence of eukaryotic cells, which would allow researchers to determine that the cell is eukaryotic and not prokaryotic. (Choice C) Ribosomes translate mRNA into proteins in both prokaryotes and eukaryotes. However, prokaryotic and eukaryotic ribosomes are composed of different subunits. Eukaryotes have larger 80S ribosomes composed of a 60S and a 40S subunit whereas prokaryotes have smaller 70S ribosomes composed of a 50S and a 30S subunit. By assessing the size of the ribosomal subunits in the pathogen, researchers can identify whether it is prokaryotic or eukaryotic. Educational objective: Eukaryotic cells contain membrane-bound organelles and linear genomes with multiple origins of replication. In contrast, prokaryotic cells lack membrane-bound organelles and have circular genomes with a single origin of replication. However, both cells have ribosomes (80S in eukaryotes and 70S in prokaryotes) and can perform glycolysis.

Researchers Are Studying a Single-Celled Pathogen