Which one of the following statements is true?a)Dysentery, plague and ...
Statement: HIV replicates in host cell with the help of reverse transcriptase enzyme.
Explanation:
HIV, which stands for Human Immunodeficiency Virus, is the causative agent of AIDS (Acquired Immunodeficiency Syndrome). It is a retrovirus that infects and replicates within host cells. The replication of HIV involves the use of reverse transcriptase enzyme.
What is reverse transcriptase?
Reverse transcriptase is an enzyme that aids in the synthesis of DNA from an RNA template. It catalyzes the reverse transcription process, where RNA is converted into DNA. HIV contains an RNA genome, and in order to replicate, it needs to convert its RNA into DNA.
Replication of HIV:
1. Attachment: HIV attaches itself to the surface of host cells, specifically CD4+ T cells and macrophages.
2. Fusion: The viral envelope fuses with the host cell membrane, allowing the entry of the viral core into the host cell.
3. Reverse Transcription: Once inside the host cell, the RNA genome of HIV is reverse transcribed into DNA by the reverse transcriptase enzyme. This DNA is known as cDNA (complementary DNA).
4. Integration: The newly synthesized cDNA is transported into the host cell nucleus and integrated into the host cell DNA. This integrated viral DNA is called a provirus.
5. Transcription: The provirus is transcribed into viral RNA molecules, which serve as both genomic RNA for new virus particles and as mRNA for the synthesis of viral proteins.
6. Translation and Assembly: The viral RNA is translated into viral proteins, which are then assembled into new virus particles.
7. Budding and Release: The new virus particles bud off from the host cell, acquiring an envelope from the host cell membrane. These newly formed viruses can now infect other host cells and continue the cycle of replication.
Significance of reverse transcriptase:
Reverse transcriptase plays a critical role in the replication of HIV. It allows the virus to convert its RNA genome into DNA, which can then be integrated into the host cell DNA. This DNA integration makes HIV difficult to eradicate from the body and enables the virus to persist and cause long-term infection.
Therefore, option B is the correct statement as HIV replicates in host cells with the help of reverse transcriptase enzyme.
Which one of the following statements is true?a)Dysentery, plague and ...
When HIV enters into the body of a person,it moves into macrophages where RNA genome of the virus replicates to form viral DNA with the help of enzyme reverse transcriptase. This viral DNA gets incorporated into cethe host cell's DNA and directs the infected cells to produce more viruses. The macrophages producing viruses, thus act as HIV enters into helper T-cells where it replicates and produces other virus. this is repeated so that the number of helper T-cells decreases in the body of the infected person. Dysentery (Bacillary) plaque and diphtheria are bacterial diseases, Ringworm appears during summer and rainy season. Widal test is used for confirmation of typhoid.
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