Which of the following virus has a double stranded DNA genome?
[NUMS-2024]
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.
Example of viruses having a polyhedral capsid that is with \( 252 \) capsomeres is:
[UHS-2024]
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Viral capsids exhibit precise, genetically determined geometric symmetries and specific capsomere counts.
Solution:- Adenoviruses are classic examples of non-enveloped, icosahedral (polyhedral) viruses.
- Their highly stable, geometric capsid is structurally composed of exactly \( 252 \) capsomeres (\( 240 \) hexons and \( 12 \) pentons at the vertices).
Why other options are incorrect:- Tobacco Mosaic Virus: Has a helical (rod-like) symmetry, not polyhedral.
- Bacteriophage: Typically has a complex (binal) symmetry with a polyhedral head and helical tail.
- Influenza virus: Has a helical nucleocapsid surrounded by a pleomorphic envelope.
The complete, mature & infectious particle of virus is known as:
[UHS-2024]
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Clear virological terminology distinguishes the actively infectious whole from its inert constituent parts.
Solution:- A virion is the official biological term for a fully assembled, complete, and infectious viral particle capable of transmitting its genome to a new host cell.
Why other options are incorrect:- Genome / Capsomere: These are simply parts of the virion (the nucleic acid and the protein subunits, respectively).
- Prion: An infectious misfolded protein entirely distinct from a virus.
Antibiotics can be used against:
[KMU-2024]
View Answer & Propolis Autopsy
Correct Key: Option A
Diagnostic Explanation
Concept:Antibiotics selectively target cellular components and metabolic pathways unique to bacteria (e.g., peptidoglycan synthesis, bacterial ribosomes).
Solution:- Salmonella typhi is a pathogenic bacterium (causative agent of typhoid fever).
- Because it is a cellular organism with its own metabolism and cell wall, antibiotics can effectively target and kill it.
Why other options are incorrect:- Herpes simplex, Influenza, Polio: These are viruses. Viruses lack cellular structures, cell walls, and independent ribosomes, making them completely immune to antibiotics. Antiviral drugs are required instead.
Which of the following is not true about viruses?
[KMU-2024]
C
They have a sub-cellular structure
D
Can replicate on their own
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Viruses are obligate intracellular parasites entirely dependent on host machinery.
Solution:- The statement "Can replicate on their own" is fundamentally false.
- Viruses possess zero metabolic enzymes and lack ribosomes. They must invade a host cell to copy their genome and synthesize their capsids.
Why other options are incorrect:- Contain DNA, Can infect bacteria, Have sub-cellular structure: These are all factual statements. Some viruses contain DNA, bacteriophages infect bacteria, and they are sub-cellular (acellular) entities.
The genetic code of ____ is bound by a lipid membrane?
[KMU-2024]
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.
Viruses cannot:
[KMU-2024]
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.
In the life cycle of a bacteriophage, the lysozymes are required in which of the following steps of infection process?
[UHS-2024]
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.
____ is transmitted through infected blood and hypodermic syringes:
[UHS-2024]
C
Vibrio cholerae (Cholera)
D
Morbilli Virus (Measles)
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Different pathogens rely on distinct bodily fluids and environmental routes for successful transmission.
Solution:- The Human Immunodeficiency Virus (HIV) is a fragile virus that cannot survive long outside the body.
- It requires direct, fluid-to-fluid contact to transmit successfully, making the sharing of infected blood via hypodermic syringes one of the most efficient transmission vectors.
Why other options are incorrect:- Influenza & Measles: These are respiratory viruses transmitted rapidly via airborne droplets.
- Vibrio cholerae: A bacterium transmitted via the fecal-oral route (contaminated water).
Where are the enzymes required for the replication of HIV virus located?
[KMU-2024]
A
Surrounding the viral core
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:Retroviruses must physically carry their replication enzymes into the host cell because the host lacks RNA-dependent DNA synthesis machinery.
Solution:- HIV packages its three essential replication enzymes (reverse transcriptase, integrase, and protease) directly inside the capsid, alongside its viral RNA genome.
- This ensures that the moment the capsid uncoats in the host cytoplasm, the enzymes are immediately available to begin reverse transcription.
Why other options are incorrect:- In the protein spikes / Outside the capsid: Enzymes placed outside the protective core would be unstable and useless during the intracellular replication phase. Spikes are strictly for attachment.
The causative organism of measles is:
[UHS-2024]
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Clinical diseases are directly mapped to specific viral families based on pathogenesis and taxonomy.
Solution:- Measles is a highly contagious respiratory disease caused by a virus belonging to the Paramyxovirus family (specifically, the Morbillivirus genus).
Why other options are incorrect:- Poxivirus: Causes smallpox and cowpox.
- Picornovirus: Causes polio and Hepatitis A.
- Paporivirus (Papillomavirus): Causes warts and cervical cancer.
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?
[NUMS-2024]
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.
Which of the following virus contains single stranded DNA?
[UHS-2023]
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).
Which of the following is not related to enveloped virus?
[SZABMU-2023]
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.
The complete, mature and infectious virus particle is known as:
[NUMS-2023]
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.
All viruses are:
[NUMS-2023]
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.
How many pieces of ribonucleic acid (RNA) make up the genome of influenza virus?
[ETEA-2023]
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.
Which of the following agents can easily pass through the filter paper?
[ETEA-2023]
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.
#19 of 59
ETEA-2023 Retake
Viruses are not classified based on:
[ETEA-2023 Retake]
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Viral taxonomy utilizes inherent structural and biological properties of the virus.
Solution:- Viruses are completely acellular. They entirely lack a cell membrane, cytoplasm, and organelles.
- Because a cell membrane is absent in all viruses, it cannot be used as a criterion for their classification.
Why other options are incorrect:- Morphology, Envelope presence, Host specificity: These are the primary criteria used universally by virologists to classify viral families.
Virus is what type of agent?
[UHS-2023]
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.
Choose the entities which requires a single cellular gene to encode the protein making up the organism:
[SZABMU-2023]
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.
____ infection is caused by a viroid:
[SZABMU-2023]
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.
The head of some phages are icosahedral, which means that the head possess:
[ETEA-2023]
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.
#24 of 59
ETEA-2023 Retake
The protein coat surrounding the genome of virus is called:
[ETEA-2023 Retake]
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Viral architecture consists of a nucleic acid interior and a protective protein exterior.
Solution:- The precise virological term for the protein coat that encloses and protects the viral genetic material is the capsid.
Why other options are incorrect:- Viroid/Phage: These describe types of infectious agents, not structural layers.
- DNA sheath: Not a standard virological term; bacteriophages have a tail sheath, but it surrounds the tail tube, not the main genomic head.
____ is transmitted through infected blood and hypodermic syringes:
[SZABMU-2023]
A
Morbilli Virus (Measles)
C
Vibrio Cholerae (Cholera)
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Pathogen transmission routes depend entirely on tissue tropism and environmental viability.
Solution:- HIV is heavily concentrated in blood, semen, and vaginal fluids.
- Direct blood-to-blood contact via shared hypodermic needles or transfusions is a highly efficient vector for transmitting the virus.
Why other options are incorrect:- Measles & Influenza: Are airborne/respiratory.
- Cholera: Is transmitted via contaminated food and water (fecal-oral).
HIV belongs to a special class of virus known as:
[ETEA-2023]
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).
#27 of 59
ETEA-2023 Retake
The genome of the human immunodeficiency virus is made up of:
[ETEA-2023 Retake]
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.
The molecules used to control virus during infection of animal cells are:
[UHS-2023]
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.
The provirus of HIV is structurally and chemically made up of?
[UHS-2023]
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:The term "provirus" refers to the specific state of the viral genome after it has been integrated into the host's chromosome.
Solution:- Once HIV enters a host cell, its single-stranded RNA (ssRNA) genome is reverse-transcribed into double-stranded DNA (dsDNA).
- This dsDNA is then transported into the nucleus and spliced into the host's DNA by the enzyme integrase. In this integrated state, it is termed a provirus.
Why other options are incorrect:- ssRNA: This is the structure of the free viral genome, not the integrated provirus.
- ssDNA / dsRNA: These are not intermediates in the HIV integration pathway.
In \( 1935 \) W. M. Stanley prepared an extract of:
[ETEA-2022]
A
Human immunodeficiency virus (HIV)
B
Tobacco mosaic virus (TMV)
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:The history of virology involves key milestones in isolating and identifying viral structures.
Solution:- In \( 1935 \), W.M. Stanley successfully prepared a crystallized extract of the Tobacco Mosaic Virus (TMV).
- This proved that viruses were particulate in nature and consisted of nucleic acids and proteins.
Why other options are incorrect:- HIV, Flu, and Polio: These viruses were not the first to be crystallized; Stanley's pioneering work was specifically on TMV.
Virus is a Latin word meaning:
[DUHS-2022]
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.
Which one can be considered as living characteristic of virus?
[NUMS-2022]
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.
Which one of the following is the characteristic of viruses?
[ETEA-2022]
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.
Which of the following virus contains single stranded DNA?
[UHS-2022]
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.
A virion is designated as:
[BUMHS-2022]
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.
Poliovirus is an example of:
[BUMHS-2022]
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).
Which of the following is a DNA virus?
[BUMHS-2022]
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.
What does the term bacteriophage refer to?
[UHS-2022]
A
Combination of bacterium and virion
B
A virus that infects bacteria
C
A virus which behaves as bacteria
D
A bacterium that infects virus
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:The nomenclature of viruses often reflects their specific host organism.
Solution:- The term "bacteriophage" is formed from "bacteria" and the Greek word "phagein" (to devour).
- It specifically refers to a virus that infects bacteria.
Why other options are incorrect:- Viruses do not behave like bacteria, nor do bacteria infect viruses. It is strictly a viral parasite of a bacterial host.
The word hepatitis means inflammation of the:
[ETEA-2022]
View Answer & Propolis Autopsy
Correct Key: Option C
Diagnostic Explanation
Concept:Medical terminology utilizes root words to designate specific anatomical structures.
Solution:- The prefix "hepato-" refers to the liver, and the suffix "-itis" indicates inflammation.
- Therefore, hepatitis is medically defined as the inflammation of the liver, typically caused by a viral infection.
Why other options are incorrect:- Inflammation of the gall bladder is cholecystitis, spleen is splenitis, and pancreas is pancreatitis.
Which one of the following pairs of disease is caused by virus?
[ETEA-2022]
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).
Hepatitis is caused by:
[DUHS-2022]
View Answer & Propolis Autopsy
Correct Key: Option D
Diagnostic Explanation
Concept:While liver inflammation can have non-infectious causes (like alcohol), infectious hepatitis is heavily associated with a specific pathogen class.
Solution:- Infectious hepatitis is primarily caused by hepatotropic viruses (such as Hepatitis A, B, C, D, and E viruses).
Why other options are incorrect:- While rare bacterial or protozoan infections can affect the liver, the standard disease known universally as "Hepatitis" is virally induced.
Rabies is caused by:
[DUHS-2022]
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.
The enzymes integrase, protease and reverse transcriptase are found in which virus?
[UHS-2022]
B
Human immunodeficiency virus
View Answer & Propolis Autopsy
Correct Key: Option B
Diagnostic Explanation
Concept:Retroviruses require a highly specialized suite of pre-packaged enzymes to complete their unique life cycle.
Solution:- The Human Immunodeficiency Virus (HIV) packages three essential enzymes within its capsid:
- Reverse transcriptase: To convert RNA into DNA.
- Integrase: To insert viral DNA into the host genome.
- Protease: To cleave viral polyproteins during maturation.
Why other options are incorrect:- Influenza, Hepatitis A, Herpes: These do not integrate via reverse transcription and lack this specific trio of enzymes.
Human immunodeficiency virus (HIV) particles are surround with a coat known as the virus envelop or membrane made up of:
[ETEA-2022]
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.
Which of the following is transmitted through infected blood and infected syringes?
[SZABMU-2022]
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).
In AIDS, 'D' stands for:
[DUHS-2022]
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.
Which of the following is not related to enveloped virus?
[PMC-2020]
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.
The complete mature and infection virus particle is known as:
[PMC-2020]
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.
Numerous opportunistic diseases might attack a person suffering from which of the following diseases:
[PMC-2020]
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.
Which of the following is not true about human immunodeficiency virus?
[PMC-2020]
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.
The genome of influenza virus is made up of:
[ETEA-2019]
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.
Capsid, the protective coat of a virus is made up of subunits known as capsomeres that are ____ in nature.
[MDCAT-2019]
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.
The bacteriophage replicates only inside the:
[ETEA-2019]
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.
In viruses, a combined structure formed by core (Nucleic Acid) and capsid is:
[MDCAT-2018]
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.
Cilia and flagella are absent in:
[MDCAT-2017]
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.
Which one is not an opportunistic disease related to HIV infection?
[ETEA-2017]
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.
AIDS is caused by:
[MDCAT-2016]
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.
HIV is classified as:
[MDCAT-2015]
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.
Which of the following cells does HIV mainly infect?
[MDCAT-2014]
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.
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