Biology Questions and Answers
AIDS
- How is HIV transmitted?
What is the disease caused by
this virus?
HIV (human immusupposed to be transmitted thnodeficiency virroughus) is
blood, semmaternal milk.en, vaginal secretions and
HIV is th(acquired immue virus that causne deficiencyes AIDS
syndrome), a disease characterized by
destruction osystem makinf cells ofg the body susce the immunptible toe (^)
many opportunistic and severediseases.
- Which type of virus is the
HIV? What is the enzyme
reverse transcriptase present
in HIV?
HIV is a retrovirus, i.e., an RNA viral (its
genetic material is RNA and not DNA).
Reverse transcriptase is a spenzyme of the retrovirus responsible ecific (^) for
the transcription of the viral RNA into
DNA withiDNA then commands tn the infected (host) cell. The production ohisf
viral proteins and the viral replication.
- What are CD4 lymphocytes?
What is the relationship
between these cells and HIV?
How does HIV replicate?
CD4 lymplymphocytes that prhocytes are T helperesent in their (^)
plasma membrane receptor proteinscalled CD4.
CD4 lympinfects and within whocytes are the cells that Hhich the virus IV
replicates. HIV has proteins in its
capsule that biof lymphocytes.nd to the Through that bond theCD4 receptors (^)
virus fuses with the cell membrane and
its content (RNA, reverse protease, etc.) penetrates into thtranscriptase,e
cytoplasm and the viral replication
process begins.
HIV RNA is then converted into DNA by
the reverse is inserted into thtranscriptase.e genetic material of The new DNA
the lymphocyte with the aid of enzymes
called integrases. Bytranslation this DNA comma transcription annds the d
synthesis of proteins nassemblage of new viruses. Loecessary for theng
polypeptides are thus produced and
then fragmented into proteins anenzymes by the enzyme protease. d viralSo
new HIV viruses are assembled and
break the cell membrane to gain thecirculation.
- Why is AIDS difficult to
prevent by vaccination?
It is difficult to produce a vaccineagainst AIDS because the HIV is a (^)
highly mreplication thutant virus. Ie produced viruses havn almost everye (^)
different proteins in their surface
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