NEET BIOLOGY

BIOLOGICAL CLASSIFICATION

VIRUSES

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
Contain a nucleoid region made up of DNA
A
Viruses
B
Bacteria
C
Both viruses and bacteria
D
Neither viruses or bacteria
Explanation: 

Detailed explanation-1: -The nucleoid is a chromatin-dense area within the cytoplasm and contains the bacterial DNA, associated proteins and RNA that are responsible for controlling the bacteria’s activity and reproduction (Fig.

Detailed explanation-2: -The nucleoid region is found in the cytoplasm of prokaryotic cells. It contains DNA, sometimes several copies of it, along with proteins, including enzymes, and RNA.

Detailed explanation-3: -The bacterial genome is present in the cell within a complex structure, the nucleoid. The nucleoid contains the genomic DNA, and molecules of RNA and proteins. The main proteins of the nucleoid are: RNA polymerase, topoisomerases and the histone-like proteins: HU, H-NS (H1), H, HLP1, IHF and FIS.

Detailed explanation-4: -Prokaryotic cells, such as bacteria, have a free-floating chromosome that is usually circular and is not enclosed in a nuclear membrane. Instead, the DNA simply exists in a region of the cell called the nucleoid. Prokaryotic cells only have a small range of organelles, generally only a plasma membrane and ribosomes.

Detailed explanation-5: -A central feature of these models is that the nucleoid structure consists of a number of separate supercoiled loops held together by RNA molecules. The loops represent separate domains of supercoiling so that nicking of a particular domain results in the relaxation of that domain only.

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