Which of the following statements are correct regarding prokaryotic genomic organization?
A. Most prokaryotes contain a single large circle of double stranded DNA as its genome.
B. The nucleoid is an irregularly shaped region that contains the cell's chromosome and numerous proteins.
C. Nucleoid associated proteins (NAPs) are not particularly important during cell division for the compaction of chromosome.
D. Prokaryotic genomes are much smaller as compared to eukaryotes. Choose the correct answer from the options given below:
Show Hint
When comparing prokaryotes and eukaryotes, remember these key genomic differences: single circular chromosome vs. multiple linear chromosomes, nucleoid vs. nucleus, and significantly smaller genome size in prokaryotes. NAPs are the prokaryotic equivalent of histones for DNA compaction.
Step 1: Understanding the Concept:
Prokaryotic cells have a simpler genomic organization than eukaryotic cells. Their genetic material is located in a region called the nucleoid and is not enclosed by a membrane. Step 2: Detailed Explanation:
Let's analyze each statement:
A. Correct. The typical prokaryotic genome is a single, circular, double-stranded DNA molecule.
B. Correct. The nucleoid is the non-membrane-bound, irregularly shaped region within a prokaryotic cell that contains the chromosome and associated proteins.
C. Incorrect. Nucleoid-associated proteins (NAPs) are analogous to eukaryotic histones. They are critically important for compacting the chromosome to fit within the cell and for its organization, including during cell division.
D. Correct. Prokaryotic genomes (typically 0.5-10 million base pairs) are orders of magnitude smaller than eukaryotic genomes (e.g., the human genome is ~3,200 million base pairs).
Step 3: Final Answer:
Statements A, B, and D are correct, while C is incorrect. Thus, the correct option is (A).
