Question 1: Define HIV and explain how it affects the immune system.

Answer: HIV (Human Immunodeficiency Virus) is a virus that infects and destroys helper T cells in the immune system, weakening the body's ability to fight infections and diseases.

Question 2: Describe the process by which HIV is transmitted from one person to another.

Answer: HIV is transmitted through exchange of body fluids such as blood, semen, vaginal fluids, and breast milk, primarily via unprotected sexual contact, sharing contaminated needles, or from mother to child during childbirth or breastfeeding.

Question 3: What is the difference between HIV and AIDS?

Answer: HIV is the virus that causes the infection, while AIDS (Acquired Immunodeficiency Syndrome) is the late stage of HIV infection when the immune system is severely weakened, leading to opportunistic infections.

Question 1: If a person has a viral load of 10,000 copies of HIV per millilitre of blood, how many copies are present in 2 litres of their blood? (1 litre = 1000 millilitres)

Answer: 20000000 copies. Calculation: 10,000 copies/mL × 2000 mL = 20,000,000 copies.

Question 2: A pharmaceutical drug needs to be administered at a dose of 50 mg per kg of body weight. Calculate the dose for a patient weighing 70 kg.

Answer: 3500 mg. Calculation: 50 mg/kg × 70 kg = 3500 mg.

Question 1: Identify three safety precautions that must be followed when handling blood samples in HIV research.

Answer: Use of gloves and protective clothing, proper disposal of sharps and contaminated materials, and working within a biosafety cabinet.

Question 2: Design a simple outline for an experiment to test the effectiveness of an HIV vaccine in a laboratory setting. Include variables and controls.

Answer: The experiment involves two groups: vaccinated and unvaccinated. Variables include vaccine type (independent), health status (dependent), and exposure to the virus (controlled). Controls include testing with a placebo and maintaining identical conditions for both groups. Outcomes measure the rate of infection or immune response.

Question 1: A study reports that in a community, 5% of HIV-positive individuals develop AIDS within 10 years without treatment. Explain what this statistic indicates about the progression of HIV to AIDS.

Answer: It indicates that, in this community, a small percentage of untreated HIV-infected individuals progress to AIDS over 10 years, highlighting the importance of treatment in preventing disease progression.

Question 1: Explain how antiretroviral therapy (ART) helps manage HIV infection and discuss its impact on the progression to AIDS.

Answer: Antiretroviral therapy (ART) involves the use of a combination of drugs that inhibit the replication of HIV within the host's cells. By reducing the viral load, ART helps preserve the immune system, particularly the helper T cells, preventing or delaying the progression to AIDS. It also decreases the chance of transmitting the virus to others. Consistent use of ART can lead to an undetectable viral load, significantly improving the quality of life for individuals with HIV.

Question 1: Describe how the development of rapid HIV testing technology has impacted public health efforts in controlling the spread of HIV.

Answer: Rapid HIV testing allows for quick diagnosis, enabling early detection and immediate counselling or treatment. This has improved contact tracing, reduced transmission rates, and increased awareness about HIV status in communities.