LAB MED EXAM 4 | QUESTIONS, ANSWERS
AND DETAILED RATIONALES | COMPLETE
STUDY GUIDE
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Updated 2026 Questions and Answers
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,Why is reverse transcriptase considered error-prone in HIV? C. It lacks proofreading capability.
A. It often misreads viral RNA sequences. Explanation: Reverse transcriptase is error-prone because it does not have a
B. It cannot replicate viral RNA efficiently. proofreading function, leading to a high mutation rate in HIV, which contributes to viral
C. It lacks proofreading capability. resistance and adaptability.
D. It only functions in specific cell types.
What is the significance of the p24 antigen in HIV? B. It is the most abundant HIV protein in the viral capsid.
A. It serves as the primary enzyme for replication. Explanation: The p24 antigen is a major structural protein found in the viral capsid and is a
B. It is the most abundant HIV protein in the viral capsid. key marker for early detection of HIV infection.
C. It helps the virus evade the immune system.
D. It determines the subtype of HIV.
Which statement best differentiates HIV-1 and HIV-2? D. HIV-1 is responsible for the global epidemic, while HIV-2 is less pathogenic and
restricted to West Africa.
A. HIV-1 causes localized outbreaks, while HIV-2 is a global
epidemic. Explanation: HIV-1 is the more virulent and widespread form of the virus, whereas HIV-2
B. HIV-1 is less pathogenic, while HIV-2 is more common has a lower transmission rate and is mostly confined to West Africa.
worldwide.
C. HIV-1 primarily affects macrophages, while HIV-2 affects
lymphocytes.
D. HIV-1 is responsible for the global epidemic, while HIV-2 is
less pathogenic and restricted to West Africa.
Is the Ag/Ab combined screening test serologic or virologic? A. serologic
A. serologic
B. virologic
Which mode of HIV transmission is the most common? C. Sexual contact
A. Contaminated needles Explanation: Sexual contact is the most common route of HIV transmission, with risk
B. Blood transfusion heightened by factors like unprotected intercourse and the presence of other STIs.
C. Sexual contact
D. Breastfeeding
,Which type of sexual activity carries the highest risk of HIV D. Receptive anal intercourse
transmission?
Explanation: Unprotected receptive anal intercourse poses the highest risk of HIV
A. Vaginal intercourse transmission due to the thin lining of the rectum, which can easily tear, facilitating the
B. Oral sex entry of the virus.
C. Mutual masturbation
D. Receptive anal intercourse
Which type of exposure listed below confers the lowest risk of B. Insertive penile-vaginal intercourse
acquiring an HIV infection?
A. Insertive anal intercourse
B. Insertive penile-vaginal intercourse
C. Receptive anal intercourse
D. Receptive penile-vaginal intercourse
What impact do untreated or undiagnosed STIs have on the C. They increase the risk of HIV transmission.
risk of HIV transmission?
Explanation: Untreated or undiagnosed STIs can cause inflammation or sores, providing
A. They lower the risk of HIV transmission. entry points for the virus and increasing susceptibility to HIV.
B. They have no effect on HIV transmission.
C. They increase the risk of HIV transmission.
D. They prevent HIV from replicating.
Which statement about perinatal HIV transmission is correct? A. It can occur during delivery or breastfeeding.
A. It can occur during delivery or breastfeeding. Explanation: HIV can be transmitted from an HIV-positive mother to her child during
B. It only occurs during breastfeeding. delivery or through breastfeeding, though effective antiretroviral therapy significantly
C. It is impossible to prevent with medical intervention. reduces this risk.
D. It does not occur if the mother has undetectable viral loads.
What is the primary outcome of untreated HIV progression C. Erosion of the immune system's integrity
over time?
Explanation: HIV gradually weakens the immune system, making the body vulnerable to
A. Increased immunity against infections infections and other complications, eventually progressing to AIDS if untreated.
B. Complete eradication of the virus
C. Erosion of the immune system's integrity
D. Reduction in viral mutation rates
, How long does it typically take for untreated HIV to progress C. 6-9 years
to AIDS?
Explanation: The progression of HIV to AIDS usually occurs over a period of 6-9 years in
A. 1-2 years untreated individuals, though this timeframe can vary depending on the individual's health
B. 3-5 years and viral factors.
C. 6-9 years
D. Over 10 years
Who are considered rapid progressors in the context of HIV? B. Individuals who develop AIDS within 1-2 years of infection
A. Individuals who remain asymptomatic for decades Explanation: Rapid progressors are individuals in whom HIV progresses unusually quickly
B. Individuals who develop AIDS within 1-2 years of infection to AIDS, typically within 1-2 years of initial infection.
C. Individuals who clear the virus naturally without treatment
D. Individuals who respond quickly to antiretroviral therapy
What are the main complications faced by individuals with A. Opportunistic infections and malignancies
AIDS?
Explanation: AIDS is characterized by a weakened immune system, leaving individuals
A. Opportunistic infections and malignancies vulnerable to opportunistic infections and cancers that the body would normally fight off.
B. Autoimmune diseases and chronic fatigue
C. Increased risk of viral resistance to antiretroviral therapy
D. Decreased susceptibility to bacterial infections
What is the typical trend in viral load as HIV progresses to C. Viral load increases as CD4 count decreases.
AIDS?
Explanation: As HIV progresses to AIDS, the immune system weakens, leading to an
A. Viral load decreases steadily. increase in viral replication and a corresponding rise in viral load.
B. Viral load remains constant throughout the disease.
C. Viral load increases as CD4 count decreases.
D. Viral load fluctuates without a specific pattern.
What occurs to the viral load during the acute phase of HIV B. Viral load peaks and then declines to a set point.
infection?
Explanation: During the acute phase, there is a sharp increase in viral load, followed by a
A. Viral load decreases significantly after initial infection. decline as the immune system mounts a partial response, stabilizing at a viral "set point."
B. Viral load peaks and then declines to a set point.
C. Viral load remains undetectable in the blood.
D. Viral load fluctuates without stabilization.
AND DETAILED RATIONALES | COMPLETE
STUDY GUIDE
| GRADED A+ | GUARANTEED SUCCESS
Updated 2026 Questions and Answers
100% Verified Exam Prep
,Why is reverse transcriptase considered error-prone in HIV? C. It lacks proofreading capability.
A. It often misreads viral RNA sequences. Explanation: Reverse transcriptase is error-prone because it does not have a
B. It cannot replicate viral RNA efficiently. proofreading function, leading to a high mutation rate in HIV, which contributes to viral
C. It lacks proofreading capability. resistance and adaptability.
D. It only functions in specific cell types.
What is the significance of the p24 antigen in HIV? B. It is the most abundant HIV protein in the viral capsid.
A. It serves as the primary enzyme for replication. Explanation: The p24 antigen is a major structural protein found in the viral capsid and is a
B. It is the most abundant HIV protein in the viral capsid. key marker for early detection of HIV infection.
C. It helps the virus evade the immune system.
D. It determines the subtype of HIV.
Which statement best differentiates HIV-1 and HIV-2? D. HIV-1 is responsible for the global epidemic, while HIV-2 is less pathogenic and
restricted to West Africa.
A. HIV-1 causes localized outbreaks, while HIV-2 is a global
epidemic. Explanation: HIV-1 is the more virulent and widespread form of the virus, whereas HIV-2
B. HIV-1 is less pathogenic, while HIV-2 is more common has a lower transmission rate and is mostly confined to West Africa.
worldwide.
C. HIV-1 primarily affects macrophages, while HIV-2 affects
lymphocytes.
D. HIV-1 is responsible for the global epidemic, while HIV-2 is
less pathogenic and restricted to West Africa.
Is the Ag/Ab combined screening test serologic or virologic? A. serologic
A. serologic
B. virologic
Which mode of HIV transmission is the most common? C. Sexual contact
A. Contaminated needles Explanation: Sexual contact is the most common route of HIV transmission, with risk
B. Blood transfusion heightened by factors like unprotected intercourse and the presence of other STIs.
C. Sexual contact
D. Breastfeeding
,Which type of sexual activity carries the highest risk of HIV D. Receptive anal intercourse
transmission?
Explanation: Unprotected receptive anal intercourse poses the highest risk of HIV
A. Vaginal intercourse transmission due to the thin lining of the rectum, which can easily tear, facilitating the
B. Oral sex entry of the virus.
C. Mutual masturbation
D. Receptive anal intercourse
Which type of exposure listed below confers the lowest risk of B. Insertive penile-vaginal intercourse
acquiring an HIV infection?
A. Insertive anal intercourse
B. Insertive penile-vaginal intercourse
C. Receptive anal intercourse
D. Receptive penile-vaginal intercourse
What impact do untreated or undiagnosed STIs have on the C. They increase the risk of HIV transmission.
risk of HIV transmission?
Explanation: Untreated or undiagnosed STIs can cause inflammation or sores, providing
A. They lower the risk of HIV transmission. entry points for the virus and increasing susceptibility to HIV.
B. They have no effect on HIV transmission.
C. They increase the risk of HIV transmission.
D. They prevent HIV from replicating.
Which statement about perinatal HIV transmission is correct? A. It can occur during delivery or breastfeeding.
A. It can occur during delivery or breastfeeding. Explanation: HIV can be transmitted from an HIV-positive mother to her child during
B. It only occurs during breastfeeding. delivery or through breastfeeding, though effective antiretroviral therapy significantly
C. It is impossible to prevent with medical intervention. reduces this risk.
D. It does not occur if the mother has undetectable viral loads.
What is the primary outcome of untreated HIV progression C. Erosion of the immune system's integrity
over time?
Explanation: HIV gradually weakens the immune system, making the body vulnerable to
A. Increased immunity against infections infections and other complications, eventually progressing to AIDS if untreated.
B. Complete eradication of the virus
C. Erosion of the immune system's integrity
D. Reduction in viral mutation rates
, How long does it typically take for untreated HIV to progress C. 6-9 years
to AIDS?
Explanation: The progression of HIV to AIDS usually occurs over a period of 6-9 years in
A. 1-2 years untreated individuals, though this timeframe can vary depending on the individual's health
B. 3-5 years and viral factors.
C. 6-9 years
D. Over 10 years
Who are considered rapid progressors in the context of HIV? B. Individuals who develop AIDS within 1-2 years of infection
A. Individuals who remain asymptomatic for decades Explanation: Rapid progressors are individuals in whom HIV progresses unusually quickly
B. Individuals who develop AIDS within 1-2 years of infection to AIDS, typically within 1-2 years of initial infection.
C. Individuals who clear the virus naturally without treatment
D. Individuals who respond quickly to antiretroviral therapy
What are the main complications faced by individuals with A. Opportunistic infections and malignancies
AIDS?
Explanation: AIDS is characterized by a weakened immune system, leaving individuals
A. Opportunistic infections and malignancies vulnerable to opportunistic infections and cancers that the body would normally fight off.
B. Autoimmune diseases and chronic fatigue
C. Increased risk of viral resistance to antiretroviral therapy
D. Decreased susceptibility to bacterial infections
What is the typical trend in viral load as HIV progresses to C. Viral load increases as CD4 count decreases.
AIDS?
Explanation: As HIV progresses to AIDS, the immune system weakens, leading to an
A. Viral load decreases steadily. increase in viral replication and a corresponding rise in viral load.
B. Viral load remains constant throughout the disease.
C. Viral load increases as CD4 count decreases.
D. Viral load fluctuates without a specific pattern.
What occurs to the viral load during the acute phase of HIV B. Viral load peaks and then declines to a set point.
infection?
Explanation: During the acute phase, there is a sharp increase in viral load, followed by a
A. Viral load decreases significantly after initial infection. decline as the immune system mounts a partial response, stabilizing at a viral "set point."
B. Viral load peaks and then declines to a set point.
C. Viral load remains undetectable in the blood.
D. Viral load fluctuates without stabilization.
