BIOLOGICAL CLASSIFICATION
VIRUSES
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
Viruses
|
|
Bacteria
|
|
Both viruses and bacteria
|
|
Neither viruses or bacteria
|
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.