Question

In a prokaryotic cell, the DNA is present in the

• A. Cell envelope
• B. Cell membrane
• C. Nucleoid
• D. Nucleus

Hint:

Remember that prokaryotes lack internal membrane-bound compartmentalization.
The suffix "-oid" means "resembling," so "nucleoid" simply means "nucleus-like" because it contains DNA but lacks a surrounding nuclear membrane.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Prokaryotic cells are characterized by the absence of a membrane-bound, true nucleus.
Unlike eukaryotic cells, which sequester their genomic material inside a double-membrane envelope, prokaryotes keep their genetic material in direct contact with the cytoplasm.

Step 2: Detailed Explanation:
The genetic material of a prokaryotic cell typically consists of a single, circular, double-stranded DNA molecule.
This chromosome is compacted into an irregularly-shaped, distinct region within the cell called the nucleoid.
The compaction of the large DNA molecule into this region is facilitated by nucleoid-associated proteins (NAPs), which are functionally analogous to eukaryotic histones.
The cell envelope refers to the outer protective layers (cell wall, membrane, glycocalyx) and does not store the genomic DNA.
The cell membrane is a lipid bilayer that acts as a selective permeability barrier.
A true nucleus is completely absent in prokaryotes.

Step 3: Final Answer:
Therefore, in a prokaryotic cell, the DNA is localized in the nucleoid region, making option (C) the correct choice.