AIDS
Read the following passage carefully and answer the given questions.
AIDS is caused by the Human Immunodeficiency Virus, which has an envelope enclosing RNA genome. Transmission of HIV infection generally occurs by (a) sexual contact with infected person, (b) transfusion of contaminated blood and blood products, (c) sharing infected needles, as in case of intravenous drug abusers; and (d) from infected mother to her child through placenta. It is important to note that HIV/AIDS is not spread by mere touch or physical contact; it spreads only through body fluids. It is, hence, imperative, for physical and psychological well-being, that they are not isolated from family and society. Infection with HIV or having AIDS is something that should not be hidden – since then, the infection may spread to many more people. HIV/AIDS-infected people need help and sympathy instead of being shunned by society.
AIDS is caused by:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Retrovirus
The passage says that AIDS is caused by the Human Immunodeficiency Virus (HIV), which has an envelope enclosing an RNA genome. HIV belongs to the group of viruses called retroviruses. A retrovirus has RNA as its genetic material. Inside the host cell it copies this RNA into DNA with the enzyme reverse transcriptase.
(1) Rhinovirus — Incorrect. Rhinoviruses cause the common cold, which infects the nose and the respiratory passage, not the immune system.
(2) Retrovirus — Correct. HIV, the virus that causes AIDS, is a retrovirus. Its RNA genome is copied into viral DNA by reverse transcriptase inside the host cell.
(3) Oncogenic Virus — Incorrect. Oncogenic viruses are viruses that can cause cancer, because they carry viral oncogenes. HIV is not grouped with them.
(4) Herpes simplex virus — Incorrect. This virus causes genital herpes, a different sexually transmitted infection.
Note: The passage is taken from NCERT. NTA has put lines of the NCERT text together to make it. Most CUET (UG) questions come straight from NCERT, so study the book line by line, including figures and their titles.
NCERT Extract:
AIDS – …
Figure 7.6 Replication of retrovirus