Free Acellular Life MCQs with Answers
342 Acellular Life MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Viruses are acellular infectious particles whose capsid, nucleic acid and host-dependent replication distinguish them from living cells. HIV infection covers transmission, replication, effects on helper T cells, progression to AIDS, symptoms, prevention and treatment, while AIDS is the disease state caused by advanced immune-system damage rather than a separate virus.
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Read the Acellular Life notesFree MDCAT chapter notes with key terms342 questions · page 6 of 18
- A. Charles Chamberland
- B. Ivanowski
- C. Twort
- D. D Herelle
Explanation: Felix d'Herelle coined the term bacteriophage for viruses that infect and destroy bacteria.
Correct answer: D Herelle- A. Louis Pasteur
- B. Edward Jennar
- C. Ivanowski
- D. Stanely
Explanation: Edward Jenner developed the first successful vaccine by using material from cowpox lesions to protect against smallpox.
Correct answer: Edward Jennar- A. 10 - 100 times
- B. 10 - 1000 times
- C. 100 - 1000 times
- D. 1000 - 10000 times
Explanation: Viruses commonly measure about 20 to 300 nm, whereas bacteria are roughly 0.5 to 5 micrometres, or 500 to 5000 nm.
Correct answer: 10 - 1000 times- A. 10 nm
- B. 20 nm
- C. 30 nm
- D. 40 nm
Explanation: The smallest commonly cited viruses, such as parvoviruses, are approximately 20 nm in diameter.
Correct answer: 20 nm- A. Sweet fluid
- B. Sore Fluid
- C. Poisonous Fluid
- D. Salty Fluid
Explanation: The word virus comes from the Latin word meaning poison or poisonous fluid, reflecting the early view that viruses were harmful agents in…
Correct answer: Poisonous Fluid- A. Protein
- B. Carbohydrate
- C. Lipid
- D. DNA
Explanation: A virus's genetic material is enclosed in a protein coat called the capsid.
Correct answer: Protein- A. Lytic cycle
- B. Lysogenic cycle
- C. Both a & b
- D. All of these
Explanation: During the lytic cycle, viral genes direct the host cell to synthesize viral nucleic acid and capsid proteins, assemble new virions and…
Correct answer: Lytic cycle- A. RNA non-enveloped
- B. RNA enveloped
- C. DNA non-enveloped
- D. DNA enveloped
Explanation: Poxviruses are large double-stranded DNA viruses surrounded by a complex envelope derived from host membranes.
Correct answer: DNA enveloped- A. All RNA viruses
- B. All DNA viruses
- C. All retroviruses
- D. All viruses
Explanation: Retroviruses contain reverse transcriptase, which copies their RNA genome into DNA so it can integrate into the host-cell genome.
Correct answer: All retroviruses- A. They can be crystallized
- B. They occur in plants and animals
- C. They are microscopic
- D. They contain DNA and can be reproduced
Explanation: Viruses contain genetic material, either DNA or RNA, and can make new virus particles inside a suitable living host cell.
Correct answer: They contain DNA and can be reproduced- A. T2
- B. T4
- C. Both A and B
- D. None
Explanation: The bacteriophage that resembles a tadpole is the T-even phage, such as the the T2, T4, and T6 phages.
Correct answer: T4- A. T phages
- B. P phages
- C. Both A and B
- D. None
Explanation: T phages carry out a lytic life cycle, which means they directly infect the bacteria and immediately kill it; however, P phages carry out…
Correct answer: T phages- A. Virulent phage
- B. Lytic phage
- C. Temperate phage
- D. Both a and b
Explanation: A lytic (virulent) phage infects a bacterium, injects its DNA, uses the host machinery to produce new phages, and causes the cell to burst…
Correct answer: Both a and b- A. Human
- B. Horse
- C. Bacteria
- D. Animal
Explanation: Bacteriophages replicate inside bacterial cells.They attach to the bacterium, inject their genetic material, use the host's machinery to…
Correct answer: Bacteria- A. Viruses
- B. Prions
- C. Fungus
- D. Amoeba
Explanation: Prions are the simplest disease-causing pathogens because they are merely misfolded proteins with with no nucleic acid (no DNA or RNA)…
Correct answer: Prions- A. Attachment
- B. Penetration
- C. Injection
- D. Replication
Explanation: Lysozyme is a digestive enzyme, so it will have to be released when the bacterial cell wall has to be digested, which occurs during the…
Correct answer: Penetration- A. 50
- B. 200
- C. 10
- D. 1000
Explanation: After 25 minutes of initial infection, about 200 bacteriophages are formed, which corresponds to the burst size of bacteriophage T4.
Correct answer: 200- A. 100-300
- B. 100-500
- C. 100-200
- D. 100-400
Explanation: During the lytic cycle of bacteriophages, the host bacterial cell is eventually lysed (burst open), releasing numerous new phage particles…
Correct answer: 100-200- A. Lack envelope
- B. Have no capsid
- C. Reverse transcriptase enzyme
- D. DNA genome
Explanation: Retroviruses are a unique group of RNA viruses that can reverse transcribe their RNA genome into DNA; that's how they are characterised.
Correct answer: Reverse transcriptase enzyme- A. Virophage
- B. Lysophage
- C. Bacteriophage
- D. None of these
Explanation: A bacteriophage is a type of virus that infects bacteria. In fact, the word "bacteriophage" literally means "bacteria eater," because…
Correct answer: Bacteriophage