Fundamentals of Microbiology: Cell Structure, Classification, and Laboratory Techniques

Which of the following structures is found in all prokaryotic cells but not in all eukaryotic cells?

Which statement best describes the main difference between Gram-positive and Gram-negative bacterial cell walls?

A bacterial culture started with 3 bacteria. The generation time is 2 hours. How many bacteria will there be after 8 hours? Use the formula $N = N_0 \times 2^n$, where $n$ is the number of generations.