Question

Look at the given figure and answer the questions:

1. What is this diagram representing?
2. Name the parts a, b, c, and d.
3. In the eukaryotes, the DNA molecules are organised within the nucleus. How is the DNA molecule organised in a bacterial cell in the absence of a nucleus?

Answer 1

1. A nucleosome
2. Histone octamer, DNA, histone and the core of the histone molecule, respectively.
3. Although bacterial cells lack a defined nucleus, the DNA is not scattered throughout the cell. Because DNA is negatively charged, it is held by certain positively charged proteins within a specific region called the 'nucleoid'. In this area, the DNA is organised into large loops that are stabilised by these proteins.