Practicing Success

Target Exam

CUET

Subject

Biology

Chapter

Human Health and Disease

Question:

Read the passage and answer the following questions :

Once inside the human body, the HIV virus enters macrophages, a type of immune cell. Within the macrophages, the viral RNA genome is replicated to form viral DNA with the assistance of an enzyme called reverse transcriptase. This viral DNA is then integrated into the DNA of the host cell, directing the infected cell to produce virus particles. The infected macrophages continue to produce the virus, acting as HIV factories. Simultaneously, the HIV virus also enters helper T-lymphocytes (TH cells) and replicates within them, producing new viruses. These progeny viruses are released into the bloodstream and target other helper T-lymphocytes, leading to a progressive decrease in their numbers. As the number of helper T-lymphocytes decreases, the infected person experiences various symptoms such as fever, diarrhea, and weight loss. Due to the decrease in helper T-lymphocytes, the person's immune system becomes severely weakened, making them susceptible to infections that could typically be overcome, including those caused by bacteria, such as Mycobacterium, viruses, fungi, and parasites like Toxoplasma. The patient becomes immunodeficient, unable to effectively protect themselves against these infections. Enzyme-linked immunosorbent assay (ELISA) is a widely used diagnostic test for AIDS, allowing for the detection of HIV infection. While antiretroviral drugs can partially prolong the life of AIDS patients, they cannot prevent death, which is inevitable without a cure for the disease. Prevention is crucial in combating AIDS since there is currently no cure. HIV infection primarily spreads through conscious behavioral patterns, unlike infections like pneumonia or typhoid that may occur inadvertently. Steps such as ensuring blood safety in blood banks, using disposable needles and syringes, promoting condom distribution, controlling drug abuse, advocating safe sex, and regular HIV check-ups in susceptible populations are taken to prevent the spread of HIV infection. It is essential not to hide HIV infection or AIDS as doing so may lead to further transmission. HIV/AIDS-infected individuals deserve help and sympathy from society instead of being stigmatized. Recognizing HIV/AIDS as a collective problem and taking collaborative actions between society and the medical fraternity are crucial in preventing the widespread dissemination of the disease. It requires a joint effort to tackle this malady and prevent its spread.

What is one of the primary symptoms experienced by an HIV-infected person due to the decrease in helper T-lymphocytes?

Options:

Bouts of fever

Weight loss

Diarrhoea

All of these

Correct Answer:

All of these

Explanation:

The correct answer is Option (4) -All of these

After getting into the body of the person, the virus enters into macrophages where RNA genome of the virus replicates to form viral DNA with the help of the enzyme reverse transcriptase. This viral DNA gets incorporated into host cell’s DNA and directs the infected cells to produce virus particles. The macrophages continue to produce virus and in this way acts like a HIV factory. Simultaneously, HIV enters into helper T-lymphocytes (TH), replicates and produce progeny viruses. The progeny viruses released in the blood attack other helper T-lymphocytes. This is repeated leading to a progressive decrease in the number of helper T-lymphocytes in the body of the infected person. During this period, the person suffers from bouts of fever, diarrhoea and weight loss. Due to decrease in the number of helper T lymphocytes, the person starts suffering from infections that could have been otherwise overcome such as those due to bacteria especially Mycobacterium, viruses, fungi and even parasites like Toxoplasma. The patient becomes so immuno-deficient that he/she is unable to protect himself/herself against these infections.