Biology · General Awareness

Viral Diseases and Immunity

807 Questions

Viral diseases and immunity cover the structure, transmission, and diagnosis of viruses like HIV. Questions focus on disease pathways, immune responses, and prevention. Strong knowledge here provides an edge in biology scoring.

HIV and AIDS structureVirus transmission methodsImmune system deficiencyPathogen risk groupsMedical diagnosis methods

Viral Diseases and Immunity Questions

Multiple choice

Retrovirus is the RNA virus with lipid envelope that uses reverses transcriptase for producing DNA macromolecules required for their replication. The better popular retroviruses, Rous Sarcoma Virus (RSV) are capable of infecting animals. The most severe human pathogen among retroviruses is the one that is the causative agent of AIDS.

“Virus which actually is the causative agent of AIDS is HIV as recommended by International Committee on Taxonomy of Virus in the year 1986.“ What was the other name used earlier for the same virus?

  1. HIV-1

  2. HIV-2

  3. HTLV-3

  4. HIV-3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The other name used earlier for the same virus was HTLV-3 (Human T-cell Leukemia Virus-3). There are two different strains: HIV-1 and HIV-2. HIV is characterised with viral Capsid such as “soccer ball” consisting of 12 pentagones and 20 hexagones attached together to form a sphere.

Multiple choice

Retrovirus is the RNA virus with lipid envelope that uses reverses transcriptase for producing DNA macromolecules required for their replication. The better popular retroviruses, Rous Sarcoma Virus (RSV) are capable of infecting animals. The most severe human pathogen among retroviruses is the one that is the causative agent of AIDS.

”There are a number of ways of detecting HIV infection among which Indirect Immunofluoresence Assay (IFA) is simple and less time consuming method.” – What actually does IFA mean?

  1. By detecting presence of anti-HIV antibodies.

  2. By testing for HIV’s proteins and nucleic acids.

  3. Amount of DNA is maximised by DNA amplification.

  4. It mixes up patient's serum with cell infected by HIV.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

During IFA, patient's serum is combined with HIV infected cell fixed to glass slide. If HIV antibodies are found in serum, they will attach to HIV antibodies exhibited on cellular surface. Antihuman antibodies sample having fluorescent complex like fluorescein isothiocyanate is included to the cells. Antihuman antibodies mix with HIV antibody on cell surface causing fluorescein tag to grow. When it is observed under fluorescent microscope, then cells will fluorescence with the green glow. If fluorescence is not there, then fluorescent complex has not accumulated on cell surface and HIV antibodies are not found in the sample.

Multiple choice

In 2015, which virus was discovered by Amit Kapoor et al. in old samples of the blood that was found to reduce the pathogenesis of HIV?

  1. Crassphage virus

  2. Human pegivirus

  3. Human hepegivirus 1

  4. Torque teno mini virus (TTMV)
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Human hepegivirus 1 was discovered by Amit Kapoor, a virologist at Columbia University, in old blood samples. Later it was shown that HIV-infected people benefit from co-infection with hepegivirus, it reduces the pathogenesis of HIV.

Multiple choice

According to a study in 2014 by Borgdorff et al, which bacterial dominance in vaginal microbiota lowers the chance of HIV, HSV-2 or HPV infection?

  1. Lactobacillus salivarius

  2. Lactobacillus vaginalis

  3. Lactobacillus crispatus

  4. Lactobacillus coleohominis
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

In 2014, it was found by Borgdorff et al. that lactobacillus crispatus is very good at trapping HIV, HSV or HPV particles and their dominance presents less chance of HIV, HSV or HPV infection.

Multiple choice

Elisa test and Western Blot test are connected with the diagnosis of

  1. AIDS

  2. Cancer

  3. Leprosy

  4. Meningitis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Elisa test and Western Blot test are connected with the diagnosis of AIDS. In an ELISA test, a person's serum is diluted 400-fold and applied to a plate to which HIV antigens have been attached. If antibodies to HIV are present in the serum, they may bind to these HIV antigens. The Western Blot is an antibody detection test. 

Multiple choice

Which of the following is a polyhedral virus?

  1. Polio virus

  2. TMV

  3. Vaccinia virus

  4. Bactreriophages

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Polio virus is a well-studied example of a polyhedral virus with icosahedral symmetry (approximately 30nm diameter, 60 structural subunits). TMV (Tobacco Mosaic Virus) is rod-shaped (helical). Vaccinia is a complex brick-shaped virus. Bacteriophages have complex geometric shapes but are typically described as having a head-tail structure.

Multiple choice

AIDS stands for

  1. Amino Immune Deficiency Syndrome

  2. Acquired Immune Deficiency Syndrome

  3. Acquired Immune Detection Syndrome

  4. Acquired Immune Deficiency Symptoms
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Correct answer is (2). 

Multiple choice

Which of the following is a doughnut-shaped virus?

  1. Calicivirus

  2. Cytomegalovirus

  3. Torovirus

  4. Astrovirus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

These viruses are pathogens for both humans and animals. They are pleiomorphic, coated, single positive strand RNA viruses. In the electron microscope, they have a doughnut shape.

Multiple choice

A virus is a small infectious agent capable of replicating only inside living cells. Which of the following viruses contain(s) a single linear double-stranded segment of DNA as its genome?

  1. Adenoviruses

  2. Epstein-Barr virus

  3. Poxviruses

  4. Parvovirus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Poxviruses viruses can infect both vertebrate and invertebrate animals. The virion is exceptionally large, and carries its genome in a single, linear, double-stranded segment of DNA.

Multiple choice

Which of the following statements regarding HIV is INCORRECT?

  1. HIV is a complex RNA virus.

  2. The lipid bilayer is studded with a number of host cell lipids and proteins.

  3. HIV has a characteristic dense, cone-shaped nucleocapsid.

  4. HIV has genes whose products contribute to the complex regulation and replication of the virus.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The lipid bilayer of HIV is studded with a number of host-cell proteins only during the budding process.

Multiple choice

After examining blood reports of an individual, doctor told him that his blood contains such proteins which indicate that now he can transmit the virus on to another person. Which among the following proteins the doctor must be referring?

  1. HBsAg

  2. LMP1

  3. NSP2

  4. HBx

  5. HBcAg
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

HBcAg (core antigen) is a hepatitis B viral protein. It is an indicator of active viral replication, thus indicating that the person infected with Hepatitis B can likely transmit the virus on to another person.

Multiple choice

Which of the following is a doughnut shaped virus?

  1. Calicivirus

  2. Cytomegalovirus

  3. Torovirus

  4. Astrovirus

  5. Norwalk virus
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

These viruses are pathogens for both humans and animals. They are pleiomorphic, coated, single positive strand RNA viruses. In the electron microscope, they have a doughnut shape.