Which of the following distinguishes this bacterial cell from eukaryotes?
a
DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.
b
The bacterial cell has both a cell membrane and a cell wall, and eukaryotes have only cell membranes.
c
Ribosomes are found in the cytoplasm of the bacterial cell, and eukaryotes do not have ribosomes.
d
The bacterial cell is a unicellular organism, and all eukaryotes are multicellular.
From Internet:
Bacteria cells do have the DNA but it is not enclosed in a nucleus. They have a very small size and cannot accommodate one. They also do not have a nuclear membrane either around the nucleus. Eukaryotic cells on the other hand have a nucleus and double nuclear membrane around it. The double membrane separates the DNA from the cytosol.
Does that help you make a choice?
The correct answer is:
b. The bacterial cell has both a cell membrane and a cell wall, and eukaryotes have only cell membranes.
To arrive at this answer, let's go through the options one by one:
a. DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.
This statement is incorrect because not all bacterial cells have their DNA in direct contact with the cytoplasm. Some bacteria have specialized structures called nucleoids that contain their DNA, which are distinct from the cytoplasm. Additionally, eukaryotes, such as plants, animals, and fungi, have their DNA enclosed within a nucleus.
b. The bacterial cell has both a cell membrane and a cell wall, and eukaryotes have only cell membranes.
This statement is correct. Bacterial cells have a cell membrane that separates the internal content from the external environment, and they also have a cell wall surrounding the cell membrane. In contrast, eukaryotic cells typically possess only a cell membrane without a cell wall.
c. Ribosomes are found in the cytoplasm of the bacterial cell, and eukaryotes do not have ribosomes.
This statement is incorrect. Ribosomes are fundamental cellular structures involved in protein synthesis, and they are present in both bacterial cells and eukaryotic cells. Therefore, ribosomes are found in both the cytoplasm of bacterial cells and eukaryotic cells.
d. The bacterial cell is a unicellular organism, and all eukaryotes are multicellular.
This statement is incorrect. While it is true that most bacteria are unicellular organisms, not all bacterial cells are unicellular. Some bacteria may form aggregates or multicellular structures. Furthermore, eukaryotes include both unicellular organisms, such as protists and yeasts, as well as multicellular organisms like plants, animals, and fungi.
Based on this analysis, the correct option that distinguishes bacterial cells from eukaryotes is b. The presence of both a cell membrane and a cell wall in bacterial cells, while eukaryotes typically have only a cell membrane.