#1 of 53
NUMS 2024
Permalink
Which of the following virus has a double stranded DNA genome?
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Viruses are heavily categorized by the Baltimore classification system, which focuses on their nucleic acid type.
Solution:- Smallpox is caused by the variola virus, which belongs to the Poxviridae family.
- Poxviruses are notable for being very large, complex viruses that contain a double-stranded DNA (dsDNA) genome.
Why other options are incorrect:- Rubella, Influenza, HIV: All of these viruses possess RNA genomes, not DNA.
#2 of 53
KMU 2024
Permalink
The genetic code of ____ is bound by a lipid membrane?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Viruses are classified structurally into naked (non-enveloped) and enveloped categories.
Solution:- The Flu virus (Influenza) is an enveloped virus.
- When it buds from the host cell, its nucleocapsid (containing the genetic code) gets wrapped in a lipid bilayer membrane derived from the host.
Why other options are incorrect:- Hepatitis A, Enterovirus, Polio virus: These all belong to the Picornaviridae family and are strictly naked (non-enveloped) viruses. Their genetic code is only bound by a protein capsid.
#3 of 53
KMU 2024
Permalink
Viruses cannot:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Viruses straddle the line between living and non-living, lacking fundamental biological processes of cellular life.
Solution:- Excretion is a physiological process required to eliminate metabolic waste.
- Because viruses have absolutely no internal metabolism or energy production, they produce no metabolic waste and therefore cannot excrete.
Why other options are incorrect:- Mutate, Infect bacteria, Crystalize: Viruses routinely mutate (e.g., flu variants), phages infect bacteria, and they can be crystallized (as proven by W.M. Stanley) because of their symmetrical, predictable biochemical structure.
#4 of 53
SZABMU 2024
Permalink
Who purified the filterable agents for the first time?
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:The timeline of virology involves sequential breakthroughs from filtration to biochemical isolation.
Solution:- While Chamberland and Ivanovsky discovered that infectious agents could pass through fine porcelain filters, it was Wendell M. Stanley in \( 1935 \) who achieved a massive breakthrough.
- He was the first scientist to successfully purify and crystallize a virus (the Tobacco Mosaic Virus), proving it was a particulate, biochemical entity rather than a fluid.
Why other options are incorrect:- Chamberland: Invented the porcelain filter.
- Ivanovsky: Proved the TMV pathogen was filterable.
- Pasteur: Developed vaccines but did not purify a virus.
#5 of 53
SZABMU 2024 Reconduct
Permalink
A virus recognizes its specific host organism by which characteristics?
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Viral tropism (host specificity) relies entirely on a "lock and key" mechanism occurring at the cellular surface.
Solution:- A virus recognizes its susceptible host via specific glycoprotein spikes or surface proteins embedded in the viral envelope (or the capsid in naked viruses).
- These surface structures act as the "key" that chemically binds to specific, matching receptor proteins on the host cell membrane.
Why other options are incorrect:- Viral/Host genome & Host cytoplasm: These are internal components. A virus must first recognize and attach to the exterior of a host cell before it can interact with the cytoplasm or genome.
#6 of 53
UHS 2024
Permalink
In the life cycle of a bacteriophage, the lysozymes are required in which of the following steps of infection process?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Bacteriophages must overcome the rigid bacterial cell wall to deliver their genetic material.
Solution:- During the penetration step, the bacteriophage must breach the thick peptidoglycan cell wall of the host bacterium.
- To do this, the phage tail releases the enzyme lysozyme, which digests a small hole in the cell wall, allowing the viral DNA to be injected into the cytoplasm.
Why other options are incorrect:- Adsorption: Refers to the initial physical attachment via tail fibers, prior to enzymatic degradation.
- Replication: Occurs internally using host polymerases.
#7 of 53
SZABMU 2024
Permalink
The side of sheath which is attached to head of bacteriophage is called:
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Complex bacteriophages (like T-even phages) have distinct mechanical parts designed for stability and genome delivery.
Solution:- The head of the bacteriophage (containing the DNA) is connected to the contractile tail sheath by a distinct neck-like structure known as the collar.
Why other options are incorrect:- Capsid: The head itself.
- End plate (Base plate): Located at the absolute bottom of the sheath, attaching to the tail fibers.
- Core: The central hollow tube inside the sheath.
#8 of 53
SZABMU 2024
Permalink
The lysozyme is involved in which step of the life cycle of bacteriophage?
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Enzymatic degradation is a mechanical necessity for phage entry into bacterial cells.
Solution:- Bacteriophages utilize viral lysozyme specifically during the penetration phase.
- The enzyme weakens the rigid bacterial peptidoglycan cell wall, allowing the phage's central tail core to drive through and inject the viral DNA.
Why other options are incorrect:- Attachment/Adsorption: Driven by electrostatic interactions and tail fiber binding.
- Assembly: The packaging of new virions inside the host, which does not require breaking the wall from the outside.
#9 of 53
NUMS 2024
Permalink
Corona virus is enveloped virus. Hand sanitizers and hand cleaners were recommended to avoid COVID epidemic. Which property of corona virus made these products effective?
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:The chemical stability of a viral envelope dictates its susceptibility to external disinfectants.
Solution:- Coronaviruses rely on an outer lipid bilayer (envelope) to protect themselves and to fuse with host cells.
- According to the provided clinical notes, this delicate lipid envelope is highly sensitive to changes in pH and alcohol concentrations. Hand sanitizers physically disrupt and dissolve this envelope, instantly neutralizing the virus.
Why other options are incorrect:- ss-RNA genome: The sanitizers destroy the outer envelope before they interact with the internal genome.
- Heat sensitivity: Sanitizers work chemically at room temperature, not via heat.
- Hypo-tonicity: Osmotic pressure does not play a primary role in alcohol-based viral inactivation.
#10 of 53
UHS 2023
Permalink
Which of the following virus contains single stranded DNA?
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:While most DNA viruses possess double-stranded genomes, distinct exceptions exist.
Solution:- The Parvo virus family is structurally unique among medically relevant DNA viruses because its genome consists of single-stranded DNA (ssDNA).
Why other options are incorrect:- Adenovirus, Herpes virus, Pox virus: All of these contain typical double-stranded DNA (dsDNA).
#11 of 53
SZABMU 2023
Permalink
Which of the following is not related to enveloped virus?
A
They are tolerant to antibodies
B
They survive for a short time
C
Their envelope is sensitive to sun light
D
Envelop is derived from host
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:An envelope provides stealth but makes the virion physically fragile and immunologically detectable.
Solution:- Enveloped viruses are highly antigenic and are NOT tolerant to antibodies.
- Antibodies readily bind to the viral glycoproteins protruding from the envelope, neutralizing the virus effectively.
Why other options are incorrect:- Short survival, derived from host, sensitive to sunlight: These are accurate characteristics of enveloped viruses, as the lipid bilayer degrades easily in external environments.
#12 of 53
NUMS 2023
Permalink
The complete, mature and infectious virus particle is known as:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Virologists use specific terminology to differentiate between a fully assembled virus and its parts.
Solution:- A virion is the fully formed, structurally intact, and infectious particle consisting of the nucleic acid genome enveloped in its protective protein capsid (and lipid envelope, if applicable).
Why other options are incorrect:- Genome/Capsid: Are sub-structural components.
- Venome: Refers to poison, not a viral particle.
#13 of 53
NUMS 2023
Permalink
All viruses are:
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Viruses lack standard metabolic pathways and energy-harvesting machinery.
Solution:- Because they possess no independent metabolic functions or ribosomes, all viruses are obligate intracellular parasites.
- They survive solely by hijacking the cellular machinery of a host.
Why other options are incorrect:- Autotrophs/Heterotrophs/Predators: These refer to cellular life forms capable of independent energy acquisition and metabolism.
#14 of 53
ETEA 2023
Permalink
How many pieces of ribonucleic acid (RNA) make up the genome of influenza virus?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Certain RNA viruses possess segmented genomes, allowing for high rates of genetic reassortment (shift).
Solution:- The genome of the Influenza A and B viruses is not a single continuous strand.
- It is divided into \( 8 \) distinct pieces (segments) of single-stranded RNA.
Why other options are incorrect:- 4, 6, 10: The biologically correct segment count for typical Influenza (A and B) is strictly 8.
#15 of 53
ETEA 2023
Permalink
Which of the following agents can easily pass through the filter paper?
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Historically, pathogens were categorized by their physical size using unglazed porcelain filters.
Solution:- Viruses are sub-microscopic entities (typically \( 20 \) to \( 300 \text{ nm} \)).
- Due to their extremely small size, they can easily pass through fine bacterial filters that trap larger cellular organisms.
Why other options are incorrect:- Bacteria, Fungi, Yeast: These are much larger cellular organisms (typically \( 1 \text{ }\mu\text{m} \) or larger) that are blocked by standard biological filters.
#16 of 53
UHS 2023
Permalink
Virus is what type of agent?
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Viruses exist on the edge of life, defined primarily by their ability to transmit disease.
Solution:- A virus is biologically classified as an obligate intracellular infectious agent.
- It is designed specifically to transfer its genetic material into a host to propagate, causing infection.
Why other options are incorrect:- Cellular agent: Viruses are acellular.
- Non-protein agent: Viruses contain protein capsids.
- Non-infectious agent: Infectivity is their defining characteristic.
#17 of 53
SZABMU 2023
Permalink
Choose the entities which requires a single cellular gene to encode the protein making up the organism:
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Subviral agents and their genetic basis.
Solution:- Prions are proteinaceous infectious particles completely devoid of nucleic acid.
- The structural protein making up a prion (\(\text{PrP}\)) is encoded by a single cellular gene (the PRNP gene) located in the host's own cellular genome.
- The normal cellular protein (\(\text{PrP}^\text{C}\)) undergoes conformational misfolding into the infectious, \(\beta\)-sheet rich scrapie isoform (\(\text{PrP}^\text{Sc}\)), which then induces further normal host protein molecules to misfold.
- Therefore, Prions require a single cellular host gene to encode their protein.
Why other options are incorrect:- A (Viroid): Viroids consist solely of tiny, naked circular RNA molecules and possess no protein coat (they do not encode or contain any protein).
- B & C (Virion / Virus): Viruses contain their own viral genome encoding multiple distinct proteins (capsid capsomeres, enzymes, envelope proteins), not a single cellular host gene.
#18 of 53
SZABMU 2023
Permalink
____ infection is caused by a viroid:
A
Mysterious brain infection
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Certain human pathogens blur the lines between standard viruses and naked viroids.
Solution:- Hepatitis D is uniquely caused by a "viroid-like" pathogen known as the Hepatitis Delta Virus (HDV).
- It possesses a tiny circular RNA genome and lacks its own envelope proteins, strictly requiring a co-infection with Hepatitis B to replicate and spread.
Why other options are incorrect:- Mad Cow / Mysterious brain infection: These are caused by prions.
- Hepatitis A: Caused by a standard picornavirus.
#19 of 53
ETEA 2023
Permalink
The head of some phages are icosahedral, which means that the head possess:
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Geometric morphology allows viruses to maximize internal volume while minimizing protein subunit variety.
Solution:- The term "icosahedral" originates from Greek, where "eikosi" means twenty and "hedra" means seat or face.
- Therefore, an icosahedral viral head structurally possesses exactly \( 20 \) triangular sides (faces).
Why other options are incorrect:- 6, 10, 15 sides: Do not correspond to the highly stable, geometric symmetry of an icosahedron.
#20 of 53
ETEA 2023
Permalink
HIV belongs to a special class of virus known as:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Viral classification relies on the nature of the genome and its replication strategy within the host cell.
Solution:- The Human Immunodeficiency Virus (HIV) carries RNA as its genetic material.
- It is classified as a retrovirus because it utilizes the enzyme reverse transcriptase to reverse the standard flow of genetic information, synthesizing DNA from its RNA genome.
Why other options are incorrect:- Flavivirus, Novavirus, Tetravirus: These are distinct viral families or genera with different genomic structures and replication mechanisms (e.g., Flaviviruses include Dengue and Zika, but they do not use reverse transcription to integrate into the host genome).
#21 of 53
ETEA 2023 Retake
Permalink
The genome of the human immunodeficiency virus is made up of:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:The native genetic material packaged inside a virion dictates its initial life cycle steps.
Solution:- Inside the infectious HIV particle (virion), the genome consists of two identical copies of single-stranded RNA.
Why other options are incorrect:- DNA/cDNA: While HIV creates a complementary DNA (cDNA) intermediate inside the host cell using reverse transcriptase, its actual packaged genome is RNA.
- rRNA: Ribosomal RNA is a cellular component used in protein synthesis, not a viral genome.
#22 of 53
UHS 2023
Permalink
The molecules used to control virus during infection of animal cells are:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Host cells possess innate biochemical defense mechanisms to limit viral spread to neighboring cells.
Solution:- When an animal cell is infected by a virus, it secretes antiviral proteins called interferons.
- These molecules bind to receptors on adjacent, uninfected cells, signaling them to produce enzymes that degrade viral RNA and inhibit viral protein synthesis, effectively "interfering" with viral replication.
Why other options are incorrect:- Antigen: The foreign molecule that triggers an immune response, not the defensive molecule.
- Histone: A structural protein for packaging DNA in eukaryotes.
- Serum: Blood plasma without clotting factors; while it contains antibodies, interferons are the specific cellular molecules secreted locally for immediate viral control.
#23 of 53
DUHS 2022
Permalink
Virus is a Latin word meaning:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:The etymology of scientific terms often traces back to their initial discovery and perceived nature.
Solution:- The word "virus" is derived from the Latin word venome, which translates to a poisonous fluid or venom.
- Historically, it was referred to as a poison associated with disease and death before its particulate nature was understood.
Why other options are incorrect:- Sweet, Acidic, Sour: These are taste and chemical descriptors unrelated to the historical Latin naming of pathogens.
#24 of 53
NUMS 2022
Permalink
Which one can be considered as living characteristic of virus?
A
Lack biosynthetic machinery
C
No cellular respiration
D
Mutate their genetic material
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Viruses exhibit a mix of both living and non-living characteristics, making them unique biological entities positioned at the borderline of life.
Solution:- A defining characteristic of life is the presence of genetic material (DNA or RNA) that can undergo replication and mutation.
- Viruses possess genomes that can mutate, allowing them to evolve and adapt to host defenses.
Why other options are incorrect:- Can be crystalized, Lack biosynthetic machinery, No cellular respiration: These are non-living characteristics of viruses.
#25 of 53
ETEA 2022
Permalink
Which one of the following is the characteristic of viruses?
A
They are facultative parasites
B
Non-facultative parasites
C
Intracellular obligate parasites
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:The ecological and biological classification of a virus depends entirely on its relationship with a host.
Solution:- Viruses are intracellular obligate parasites.
- This means they strictly require the internal environment of a host cell to replicate and survive. They cannot reproduce independently.
Why other options are incorrect:- Facultative parasites: These can live independently or as parasites. Viruses cannot live independently.
#26 of 53
UHS 2022
Permalink
Which of the following virus contains single stranded DNA?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:While most DNA viruses are double-stranded, there are specific exceptions in viral taxonomy.
Solution:- Parvovirus is a unique and medically significant virus because it is the primary family of viruses containing a single-stranded DNA (ssDNA) genome.
Why other options are incorrect:- Adenovirus, Herpes virus, Pox virus: All of these contain double-stranded DNA (dsDNA) genomes.
#27 of 53
BUMHS 2022
Permalink
A virion is designated as:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:The functional state of a virus is described by specific terminology.
Solution:- A virion is officially defined as the complete virus particle.
- It is fully equipped with its nucleic acid and protective coat, ready to infect a living cell.
Why other options are incorrect:- Viral enzyme, Viral genome: These are sub-components of the virus, not the complete infectious particle.
- Viral lysosome: Viruses do not possess lysosomes.
#28 of 53
BUMHS 2022
Permalink
Poliovirus is an example of:
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Viruses are classified structurally based on their capsid symmetry.
Solution:- The Poliovirus possesses an icosahedral symmetry, which gives it a roughly spherical appearance under an electron microscope.
Why other options are incorrect:- Tadpole shaped: Characteristic of bacteriophages.
- Rod/Helical shaped: Characteristic of viruses like the Tobacco Mosaic Virus (TMV).
#29 of 53
BUMHS 2022
Permalink
Which of the following is a DNA virus?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Identifying the nucleic acid core of major human pathogens is critical in viral classification.
Solution:- The Herpes virus is a prominent example of a virus containing a double-stranded DNA (dsDNA) genome.
Why other options are incorrect:- Polio, Influenza, and Mumps viruses: All of these contain RNA genomes.
#30 of 53
ETEA 2022
Permalink
Which one of the following pairs of disease is caused by virus?
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Recognizing clusters of pathogen types is vital for diagnosis and treatment.
Solution:- Measles and Mumps are both highly contagious diseases caused by viruses belonging to the Paramyxoviridae family.
Why other options are incorrect:- Syphilis and TB: Both are bacterial infections.
- Tetanus and Cholera: Both are bacterial infections.
- AIDS and Typhoid: AIDS is viral (HIV), but Typhoid is bacterial (Salmonella).
#31 of 53
DUHS 2022
Permalink
Rabies is caused by:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Viral families are classified based on the diseases they cause and their morphological features.
Solution:- Rabies is a deadly neurological disease caused by the Rhabdovirus (specifically, the rabies virus), which has a distinct bullet-like shape.
Why other options are incorrect:- Paramyxovirus: Causes measles and mumps.
- Arbovirus: Arthropod-borne viruses (e.g., Dengue).
- Rhinovirus: The primary cause of the common cold.
#32 of 53
ETEA 2022
Permalink
Human immunodeficiency virus (HIV) particles are surround with a coat known as the virus envelop or membrane made up of:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Viral envelopes are structurally derived from the host cell but modified by the virus.
Solution:- When HIV buds out of a host cell, it wraps itself in a section of the host's plasma membrane.
- This biological membrane is primarily composed of lipids with embedded viral proteins, classifying it biochemically as a lipoprotein envelope.
Why other options are incorrect:- Glycoprotein: Refers specifically to the spikes (gp120/gp41) sticking out of the envelope, not the continuous membrane layer itself.
#33 of 53
SZABMU 2022
Permalink
Which of the following is transmitted through infected blood and infected syringes?
B
Morbili virus (Measles)
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Pathogens evolve specific modes of transmission based on their environmental stability and tissue tropism.
Solution:- HIV is a blood-borne pathogen.
- It requires direct exchange of bodily fluids and is heavily transmitted through the sharing of infected needles/syringes and blood transfusions.
Why other options are incorrect:- Influenza & Measles: Transmitted via respiratory aerosols/droplets.
- Vibrio cholerae: Transmitted via the fecal-oral route (contaminated water).
#34 of 53
DUHS 2022
Permalink
In AIDS, 'D' stands for:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Medical acronyms describe the clinical manifestation of the disease.
Solution:- AIDS stands for Acquired ImmunoDeficiency Syndrome.
- "Deficiency" highlights the core pathology: the profound depletion of the body's immune cells.
Why other options are incorrect:- Decompose, Degenerate, Difficult: These are not part of the standard medical nomenclature for the disease.
#35 of 53
PMC 2020
Permalink
Which of the following is not related to enveloped virus?
A
They survive for a short time
B
Their envelop is sensitive to sunlight
C
They are tolerant to antibodies
D
Envelope is derived from host
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:The lipid envelope of a virus dictates its stability in the environment and its interaction with the host immune system.
Solution:- Enveloped viruses are generally fragile outside a host because their lipid envelope is susceptible to heat, detergents, and desiccation.
- They are NOT tolerant to antibodies. The host immune system easily targets surface proteins (spikes) on the envelope, neutralizing the virus.
Why other options are incorrect:- Short survival, sensitive to sunlight, derived from host: These are all true characteristic facts regarding enveloped viruses.
#36 of 53
PMC 2020
Permalink
The complete mature and infection virus particle is known as:
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Terminology in virology strictly defines different states and structures of the virus.
Solution:- A virion is the fully assembled, mature, and infectious viral particle capable of transmitting its genome to a new host cell.
- It includes the genome, the capsid, and occasionally an envelope.
Why other options are incorrect:- Genome/Capsid: These are merely parts of the virion.
- Venom: Refers to a biological toxin, not an infectious particle.
#37 of 53
PMC 2020
Permalink
Numerous opportunistic diseases might attack a person suffering from which of the following diseases:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:A severely compromised immune system creates an environment where normally harmless microbes become lethal.
Solution:- AIDS destroys T-helper cells, creating severe immunodeficiency.
- This allows numerous opportunistic pathogens (fungi, bacteria, atypical viruses) to successfully attack and overwhelm the patient.
Why other options are incorrect:- Measles, Influenza, Hepatitis A: While these can cause temporary immune stress, they do not systemically and permanently destroy the immune system to allow a cascade of opportunistic diseases like AIDS does.
#38 of 53
PMC 2020
Permalink
Which of the following is not true about human immunodeficiency virus?
B
It is surrounded by an envelope
D
It causes deficiency of the human immune system
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Understanding the direct causal relationship between HIV and its clinical pathology is fundamental to virology.
Solution:- The statement "It does not cause AIDS" is patently false.
- HIV is the sole, direct causative agent of Acquired Immunodeficiency Syndrome (AIDS).
Why other options are incorrect:- Retrovirus, Enveloped, Causes deficiency: All of these are factually true statements describing the nature and mechanism of HIV.
#39 of 53
NTS 2019
Permalink
Virus can only survive and reproduce inside a:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Viruses are defined by their obligate intracellular parasitic nature.
Solution:- Viruses lack the independent metabolic machinery required for reproduction.
- They must infect a living cell (host) to hijack its biosynthetic machinery (ribosomes, enzymes) to replicate.
Why other options are incorrect:- Animal/Bacterial cells: These are specific types of living cells, but viruses infect a wide variety of living cells (plants, fungi, etc.), making "Living cells" the most comprehensive and correct answer.
- Non-living cells: Viruses cannot replicate in dead or non-living environments.
#40 of 53
ETEA 2019
Permalink
The genome of influenza virus is made up of:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Different families of viruses carry different forms of nucleic acids as their genome.
Solution:- The Influenza virus belongs to the Orthomyxoviridae family.
- Its genetic material is composed of segmented, single-stranded RNA (ssRNA).
Why other options are incorrect:- ssDNA, dsDNA, dsRNA: These genomes are found in other viral families (e.g., Parvovirus has ssDNA, Adenovirus has dsDNA), not Influenza.
#41 of 53
MDCAT 2019
Permalink
Capsid, the protective coat of a virus is made up of subunits known as capsomeres that are ____ in nature.
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:The viral capsid provides structural integrity and protection to the viral genome.
Solution:- The capsid is a protective coat assembled from smaller, repeating structural subunits called capsomeres.
- Biochemically, capsomeres are entirely protein in nature.
Why other options are incorrect:- Lipid: Found in the viral envelope, not the capsid.
- DNA/RNA: These form the viral genome, not the protective coat.
#42 of 53
NTS 2019
Permalink
Genome of virus is composed of:
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept: Nucleic acid composition across viral families.
Solution: Unlike cellular organisms which strictly use dsDNA, viruses can utilize either DNA or RNA as their primary genetic material.
#43 of 53
ETEA 2019
Permalink
The bacteriophage replicates only inside the:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Viruses exhibit high host specificity determined by viral surface proteins and host cell receptors.
Solution:- A bacteriophage (phage) translates to "bacteria eater."
- It is highly specialized to recognize, infect, and replicate only inside a bacterial cell.
Why other options are incorrect:- Animal/Fungal cells: Bacteriophages cannot bind to or infect eukaryotic cells because they lack the required host receptors.
#44 of 53
AJK 2019
Permalink
The main target of HIV in AIDS is:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:HIV exhibits strict cellular tropism mediated by the CD4 surface receptor.
Solution:- The main target of HIV is the Helper T-lymphocytes (CD4+ cells), which serve as the "command centers" of the immune system.
- The destruction of these cells leads to the catastrophic immune failure seen in AIDS.
Why other options are incorrect:- Red blood cells, B-lymphocytes, Liver cells: Do not express the required CD4 receptor necessary for primary HIV attachment and entry.
#45 of 53
MDCAT 2018
Permalink
In viruses, a combined structure formed by core (Nucleic Acid) and capsid is:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:The structural anatomy of a virus is composed of fundamental morphological units.
Solution:- All viruses contain a genome (either DNA or RNA) and a protective protein coat called a capsid.
- Together, the nucleic acid core and the surrounding capsid are collectively referred to as the nucleocapsid.
Why other options are incorrect:- Envelope: A lipid bilayer outside the nucleocapsid.
- Capsomeres: Individual protein subunits that make up the capsid.
- Prions: Infectious proteins lacking nucleic acids entirely.
#46 of 53
NTS 2018
Permalink
Which of the following is the simplest forms of pathogens causing disease?
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Pathogens vary dramatically in structural complexity, from multicellular organisms down to mere molecules.
Solution:- Prions are the absolute simplest known infectious agents.
- They are composed exclusively of misfolded proteins and contain absolutely no genetic material (neither DNA nor RNA).
Why other options are incorrect:- Viruses: More complex as they contain both nucleic acids and proteins.
- Fungus/Amoeba: Highly complex eukaryotic organisms.
#47 of 53
NTS 2018
Permalink
Which is not a viral disease?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Distinguishing between the causative agents of major human diseases is a fundamental aspect of pathology.
Solution:- Malaria is not a viral disease. It is caused by Plasmodium, which is a single-celled eukaryotic parasite (a protozoan).
Why other options are incorrect:- AIDS (HIV), Chicken pox (Varicella-zoster), Influenza: These are all highly common viral diseases.
#48 of 53
MDCAT 2017
Permalink
Cilia and flagella are absent in:
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Viruses are highly simplified, acellular infectious entities that lack typical cellular motility structures.
Solution:- Viruses are infectious particles made up of a protein coat (capsid) and a genome (DNA or RNA).
- They completely lack cellular organelles, cytoplasm, and motility appendages like cilia and flagella.
Why other options are incorrect:- Lower plants, Bacteria, Lower animals: Many species within these groups possess flagella or cilia for locomotion.
#49 of 53
ETEA 2017
Permalink
Which one is not an opportunistic disease related to HIV infection?
B
Destruction of body immune system
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Opportunistic infections are secondary diseases that strike because the host's primary immune defenses have been compromised.
Solution:- Destruction of body immune system is the direct, primary physiological effect of the HIV virus itself, not an "opportunistic disease."
- It is the cause of the susceptibility, not the secondary infection.
Why other options are incorrect:- Tuberculosis, Pneumonia, Toxoplasmosis: These are classic opportunistic infections that heavily afflict AIDS patients due to their destroyed immune systems.
#50 of 53
MDCAT 2016
Permalink
AIDS is caused by:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Acquired Immunodeficiency Syndrome (AIDS) represents the advanced stage of a specific infection.
Solution:- AIDS is caused by the Human Immunodeficiency Virus (HIV).
Why other options are incorrect:- Fungi, Bacteria, Alga: While AIDS patients may die from secondary fungal or bacterial infections due to immunodeficiency, the underlying cause of the syndrome is viral.
#51 of 53
MDCAT 2015
Permalink
HIV is classified as:
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Viral classification is often based on the type of genetic material and the mode of replication.
Solution:- HIV (Human Immunodeficiency Virus) is a retrovirus.
- Retroviruses are RNA viruses that use the enzyme reverse transcriptase to convert their single-stranded RNA genome into double-stranded DNA within the host cell.
Why other options are incorrect:- Bacteriophage: A virus that infects bacteria.
- Oncovirus: A virus that primarily causes cancer.
- Icosahedral virus: Refers to shape, but retrovirus is the specific biological classification for HIV.
#52 of 53
KMDC 2014
Permalink
Polio vaccine is given by:
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Vaccine administration routes vary based on the formulation and the targeted immune response.
Solution:- The live attenuated Polio vaccine (Sabin vaccine) is famously administered globally via oral drops.
- This method simulates the natural fecal-oral route of polio infection, strongly stimulating mucosal immunity in the intestines.
Why other options are incorrect:- Spray, Tablets, Local application: Not the standard administrative routes for the polio vaccine. (Note: The inactivated Salk vaccine is given by injection).
#53 of 53
MDCAT 2014
Permalink
Which of the following cells does HIV mainly infect?
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Viruses bind to specific host cell surface receptors to gain entry.
Solution:- HIV uses its gp120 spike protein to specifically target and bind to CD4 receptors.
- These CD4 receptors are predominantly found on the surface of T-helper lymphocytes. By destroying these cells, HIV cripples the human immune system.
Why other options are incorrect:- T-killer, B-plasma, B-memory cells: These lack the dense concentration of CD4 receptors required for primary HIV entry.
The Complete Combat Engine
Ready to Score 180+ in MDCAT 2026?
Join thousands of pre-med students utilizing BeambePrep's full combat suite: Swarm Mode timed challenges, Normal Grind Mode, Propolis Ward mistake notebooks, Infinite Full-Length Practice (FLP) Mocks, and FSRS Spaced Repetition.