USA Biology Olympiad (USABO) Practice Exam

Which of the following are characteristics shared by both bacteria and fungi?

1. Nucleus and mitochondria

2. Cell wall, DNA, and plasma membrane

3. Chloroplast and RNA

4. Cell membrane, ribosomes, and lysosomes

The correct answer is: Cell wall, DNA, and plasma membrane

Bacteria and fungi share several fundamental characteristics that highlight their similarities as living organisms. Both groups possess a cell wall, which provides structural support and protection. Although the composition of their cell walls differs—bacteria typically have peptidoglycan in their walls, while fungi have chitin—the presence of a cell wall is a shared trait. In addition to the cell wall, both groups have DNA that contains the genetic information necessary for their growth, reproduction, and functioning. The DNA in both bacteria and fungi is essential for coding various proteins and guiding metabolic processes. Lastly, both bacteria and fungi possess a plasma membrane, which is crucial for maintaining the cell's integrity, transporting nutrients, and regulating the internal environment. The plasma membrane serves as a barrier between the cell and its surroundings, allowing selective exchange of substances. The other choices highlight features that are not universally shared between bacteria and fungi. For example, the presence of a nucleus and mitochondria is characteristic of eukaryotes, which includes fungi, but bacteria are prokaryotes and do not have a nucleus or mitochondria. Chloroplasts are found in photosynthetic organisms, primarily plants and some protists, and are not a feature of either bacteria or fungi. Lastly, while