The diagram below shows the structure of a bacterial cell.

Question

Which of the following distinguishes this bacterial cell from eukaryotes?

a
The bacterial cell has both a cell membrane and a cell wall, and eukaryotes have only cell membranes.
b
Ribosomes are found in the cytoplasm of the bacterial cell, and eukaryotes do not have ribosomes.
c
The bacterial cell is a unicellular organism, and all eukaryotes are multicellular.
d
DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.

Answer 1

The correct answer is:

d
DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.

This statement highlights a key distinction between bacterial (prokaryotic) cells and eukaryotic cells. Bacteria have their genetic material (DNA) located in a nucleoid region that is not membrane-bound, while eukaryotic cells have their DNA contained within a membrane-bound nucleus.

Let's briefly assess the other statements:

• a: While it is true that bacterial cells have both a cell membrane and a cell wall, many eukaryotic cells (like plant cells) also have cell walls in addition to cell membranes.
• b: This is incorrect because eukaryotes also contain ribosomes; they just differ in size and location compared to those in prokaryotes.
• c: This is overly simplistic; while many eukaryotes are multicellular, there are also unicellular eukaryotes (like many protists and some fungi).

Thus, option d accurately captures a fundamental difference between bacterial and eukaryotic cells.