The diagram below shows the structure of a bacterial cell.
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
DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.
d
The bacterial cell is a unicellular organism, and all eukaryotes are multicellular.
c
c
DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.
The correct answer is c. DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.
To arrive at this answer, let's look at the options provided:
a. The bacterial cell has both a cell membrane and a cell wall, and eukaryotes have only cell membranes. This is not a distinguishing characteristic, as many eukaryotic cells also have cell walls in addition to cell membranes. For example, plant cells have both a cell wall and a cell membrane.
b. Ribosomes are found in the cytoplasm of the bacterial cell, and eukaryotes do not have ribosomes. This option is incorrect because both bacterial cells and eukaryotic cells have ribosomes. Ribosomes are responsible for protein synthesis and are found in the cytoplasm of all cells.
c. DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus. This option is the correct answer. Bacterial cells have a single, circular DNA molecule that is not enclosed within a nucleus. In contrast, eukaryotes have multiple linear DNA molecules that are grouped into chromosomes and are located inside a membrane-bound nucleus.
d. The bacterial cell is a unicellular organism, and all eukaryotes are multicellular. This option is incorrect because while it is true that bacterial cells are typically unicellular, there are also many examples of unicellular eukaryotes. Examples include protists like amoebas and paramecia.
Therefore, by analyzing the options and understanding the characteristics of bacterial cells and eukaryotic cells, we can conclude that the correct answer is c. DNA in the bacterial cell is always in contact with the cytoplasm, and all eukaryotes have DNA located inside a nucleus.