intro
MCQs 1:
What type of parasites can viruses be classified as?
Topic: Parasitology and Virology
Correct Answer: B) Obligate parasites
- Viruses are unique microorganisms that must infect living cells to reproduce, hence classified as "obligate parasites".
- While all given options represent different types of parasites, only obligate parasites such as viruses are entirely dependent on the host's cellular machinery for their replication.
- So, the correct answer is B, "Obligate parasites".
MCQs 2:
Which of the following assertions is accurate?
Topic: Microbiology – Viruses and Fungi
Correct Answer: C) A virus cannot contain both DNA and RNA
- A virus is a biological entity that utilizes the replication machinery of its host organism for multiplication - either DNA or RNA, but never both.
- For instance, viruses containing DNA are known as deoxyviruses, while those containing RNA are referred to as riboviruses.
- Hence, the correct answer is C, "A virus cannot contain both DNA and RNA."
MCQs 3:
Which among the following statements is incorrect?
Topic: Microbiology – Viruses and Prions
Correct Answer: B) The protein coat is the infective constituent in viruses
- Viruses infect their host organisms through their genetic material, either DNA or RNA, not through their protein coat.
- They commandeer the host cell's biosynthetic machinery to produce chemicals needed for their own multiplication.
- Thus, the incorrect statement is B, "The protein coat is the infective constituent in viruses."
MCQs 4:
What do we call a virus that possesses nucleic acid but lacks a protein coat?
Topic: Microbiology – Viruses and Viroids
Correct Answer: B) Viroid
- Viroids are the smallest known pathogens, consisting of small, circular, single-stranded RNA molecules. They lack any kind of protein capsid, making them totally dependent on host function for replication.
- Other options represent different components or forms of viruses, but only viroids match the given description.
- Therefore, the correct answer is B, "Viroid".
MCQs 5:
Why isn't a standalone virus classified as a living entity?
Topic: Microbiology – Viruses and Life Status
Correct Answer: B) It lacks metabolic capabilities
- A standalone virus is considered non-living primarily because it lacks one of the fundamental characteristics of life - metabolism.
- Unlike living organisms that can produce, convert, and utilize energy, a virus outside a host cell is metabolically inert, thereby classifying it as non-living.
- Hence, the correct answer is B, "It lacks metabolic capabilities."
MCQs 6:
What kind of nucleic acid can a virus contain?
Topic: Microbiology – Viruses and Nucleic Acids
Correct Answer: D) Either DNA or RNA
- Viruses are unique in the sense that they can contain either DNA or RNA as their genetic material, but not both simultaneously.
- This allows for a diverse range of viruses with different replication strategies and host interaction mechanisms.
- Therefore, the correct answer is D, "Either DNA or RNA."
MCQs 7:
What components does a virus possess?
Topic: Microbiology – Viruses and Components
Correct Answer: D) Nucleic acid and Protein
- Viruses are complex entities that straddle the line between living and non-living. They consist of a nucleic acid core (either DNA or RNA but not both) and a protein coat known as a capsid.
- The nucleic acid carries the genetic material for replication, while the protein coat protects this genetic material and aids in infecting host cells.
- Thus, the correct answer is D, "Nucleic acid and Protein."
MCQs 8:
What is the type of genetic material carried by the virus causing AIDS?
Topic: Microbiology – HIV and Genetic Material
Correct Answer: B) Single-stranded RNA
- HIV, the virus responsible for AIDS, is a type of retrovirus. Retroviruses are unique in that they carry single-stranded RNA as their genetic material.
- Retroviruses also possess an enzyme called reverse transcriptase, which facilitates the conversion of RNA into DNA, enabling HIV to infect human cells.
- Therefore, the correct answer is B, "Single-stranded RNA."
MCQs 9:
Which of the following assertions about viruses are accurate?
Topic: Microbiology – Viruses and Characteristics
Correct Answer: C) (iii) and (iv)
- Viruses are non-cellular, infectious entities composed of nucleoprotein. They cannot be grown in culture mediums as they rely on host cells for replication.
- The genetic material of viruses is either DNA or RNA, but not both, which is reflected in option (iii).
- Viruses can also be crystallized, as mentioned in option (iv).
- Therefore, the correct answer is C, "(iii) and (iv)."
MCQs 10:
Which of the following viruses is the smallest known to exist?
Topic: Microbiology – Viruses and Size
Correct Answer: C) Polio
- The poliovirus is one of the smallest and simplest known viruses. It is composed of a protein shell or capsid, which is approximately 30 nanometers in diameter.
- Despite their simplicity, viruses like the poliovirus can cause severe diseases.
- Thus, the correct answer is C, "Polio."
MCQs 11:
Identify the possession of viruses from the following:
Topic: Microbiology – Viruses and Genetic Material
Correct Answer: C) Either DNA or RNA
- Contrary to living cells, viruses do not possess ribosomes or organelles, hence options A and B are incorrect.
- Viruses carry one type of nucleic acid, either DNA or RNA, but not both, hence option C is correct.
- Therefore, the correct answer is C, "Either DNA or RNA."
MCQs 12:
Which of the following best describes the difference between viruses and viroids?
Topic: Microbiology – Viruses vs. Viroids
Correct Answer: A) Absence of protein coat in viroids but present in viruses
- Viruses are nucleoprotein entities that have a protein coat, unlike viroids which lack this protein coat, thus option A is correct.
- The statement in option B is incorrect since viroids, not viruses, possess low molecular weight RNA.
- Therefore, the correct answer is A, "Absence of protein coat in viroids but present in viruses."
MCQs 13:
How is HIV classified?
Topic: Microbiology – HIV Classification
Correct Answer: C) Retrovirus
- Bacteriophages infect bacteria, and HIV, which infects human cells, is not a bacteriophage, thus making option A incorrect.
- Oncoviruses are associated with cancer, but HIV, while it can lead to conditions that increase cancer risk, is not an oncovirus, hence option B is incorrect.
- HIV is a retrovirus, which is a type of virus that carries RNA as genetic material and reverse transcribes it into DNA in the host cells, making option C correct.
- Therefore, the correct answer is C, "Retrovirus."
MCQs 14:
Which of the following best represents the constituents of the virus responsible for AIDS?
Topic: Microbiology – Constituents of HIV
Correct Answer: A) Proteins bound with RNA
- The AIDS virus, known as HIV, belongs to the family-Retroviridae, and is a lentivirus. It has a core composed of two single strands of RNA molecules, proteins, and the reverse transcriptase enzyme.
- Therefore, the correct answer is A, "Proteins bound with RNA."
MCQs 15:
What distinguishes a virus from a bacterium?
Topic: Microbiology – Virus vs Bacterium
Correct Answer: D) Presence of DNA or RNA as genetic material
- Viruses, in addition to proteins, contain genetic material that could be either RNA or DNA, but not both. They lack characteristics like a cell wall, cytosol, or ribosomes, which are found in bacteria.
- Therefore, the correct answer is D, "Presence of DNA or RNA as genetic material."
MCQs 16:
Which kingdom do viruses belong to?
Topic: Microbiology – Classification of Viruses
Correct Answer: D) None
- Viruses are non-cellular, ultramicroscopic, and highly infectious entities that multiply only within living host cells, without growth or division. They are considered intermediates between non-living entities and living organisms, and their status as living or non-living is challenging to determine.
- Therefore, the correct answer is D, "None." Viruses do not belong to any known kingdom.
MCQ 17:
What does the term "Virus" translate to?
Topic: Microbiology – Definition of Virus
Correct Answer: C) Poison
- The word "Virus" has its origin in the Latin language where it translates to "Venom" or "Poison."
- Therefore, the correct answer is C, "Poison."
MCQ 18:
What is the composition of the viral envelope that surrounds the protein coat?
Topic: Microbiology – Viral Composition
Correct Answer: C) Lipoprotein
- Viruses are small infectious agents that multiply only within the living cells of other organisms.
- Some viruses are encompassed by a lipid bilayer containing viral proteins, which helps them bind to host cells.
- This structure, made of lipids and proteins, is referred to as the virus envelope, and it originates from the host cell membranes.
- Consequently, the correct answer is C, "Lipoprotein." The viral envelope is not composed solely of protein, lipids, or mucilage.
MCQ 19:
What is the term for the protein coat of a virus?
Topic: Microbiology – Viral Structure
Correct Answer: A) Capsid
- A capsid is the term used to describe the protein coat of viruses.
- It functions to safeguard the nucleoid and any present enzymes.
- Capsids are composed of identical protein subunits known as capsomeres, the quantity and arrangement of which are virus-specific.
- Therefore, the correct answer is A, "Capsid."
MCQ 20:
Which of the following is not found in viruses?
Topic: Microbiology – Viral Characteristics
Correct Answer: D) Metabolic machinery
- Viruses are acellular entities that do not possess the biosynthetic machinery needed for reproduction.
- They need to infect a host cell and use its metabolic machinery for replication.
- Therefore, the correct answer is D, "Metabolic machinery."
MCQ 21:
What are the constituents of a capsid in viruses?
Topic: Microbiology – Viral Structure
Correct Answer: A) Capsomeres
- The capsid is an outer protective layer that encompasses the virus and is made up of a specific number of protein subunits known as capsomeres.
- These capsomeres are usually associated with or found near the virus's nucleic acid.
- Hence, the correct answer is A, "Capsomeres."
MCQ 22:
What can't viruses generate or synthesize due to their lack of metabolic machinery?
Topic: Microbiology – Viral Metabolism
Correct Answer: D) All of these
- Viruses lack their own metabolic machinery, which means they can't generate energy or synthesize any substances, including proteins, carbohydrates, alcohol, etc.
- They rely on the host cell's metabolic machinery for these processes.
- Consequently, the correct answer is D, "All of these."
MCQ 23:
Which entity can be described as a parasitic being encapsulated in a protein coat with either DNA or RNA?
Topic: Microbiology – Viral Structure
Correct Answer: C) Virus
- A virus is a parasitic agent that has its genetic material (either DNA or RNA) enclosed in a protein coat known as a capsid.
- Thus, the correct answer is C, "Virus."
MCQ 24:
Which of the following correctly encapsulates characteristics of viruses?
Topic: Microbiology – Viral Characteristics
Correct Answer: D) All the above
- Viruses are submicroscopic infectious entities, obligate parasites, meaning they can only multiply or replicate inside a host cell.
- Their genetic material is composed of either DNA or RNA.
- Therefore, the correct answer is D, "All the above."
MCQ 25:
What disease is caused by the Human Immunodeficiency Virus?
Topic: Microbiology – Viral Diseases
Correct Answer: B) Acquired Immune Deficiency Syndrome
- Human Immunodeficiency Virus (HIV) is a virus that can lead to the development of Acquired Immune Deficiency Syndrome (AIDS).
- AIDS is a condition in humans in which the immune system begins to fail, leading to life-threatening opportunistic infections.
- As a result, the correct answer is B, "Acquired Immune Deficiency Syndrome."