Free Biodiversity and Variety of Life MCQs with Answers
3,130 Biodiversity and Variety of 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.
Biological classification uses taxonomic ranks, binomial nomenclature and shared characteristics to organize life into kingdoms. The major groups include prokaryotes, protists, fungi, plants and animals, with comparisons based on cell type, cell wall, nutrition, body organization, reproduction and evolutionary relationships; prokaryotes lack a membrane-bound nucleus.
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641. When a virus enters a cell and incorporates its RNA or DNA into host DNA, what is this stage called?
- A. Lysogeny
- B. Fermentation
- C. Symbiosis
- D. Synergism
Explanation: The correct answer is A, as the stage when a virus enters a cell and incorporates its RNA or DNA into host DNA is called lysogeny.
Correct answer: Lysogeny- A. T4 phage
- B. Provirus
- C. Prophage
- D. Bacteriophage
Explanation: The correct answer is C) prophage. A prophage is a phage genome that has been incorporated into the host cell's DNA.
Correct answer: Prophage- A. Virion
- B. Viroid
- C. Prion
- D. Virus
Explanation: The answer is B) viroid. A viroid is a small, infectious RNA molecule that does not have a protein coat (capsid).
Correct answer: Viroid- A. 100 mm to 150 mm
- B. 20 nm to 250 nm
- C. 300 nm to 3000 nm
- D. 3 nm to 30 nm
Explanation: The size of a virus ranges between 20 nm and 250 nm.
Correct answer: 20 nm to 250 nm645. What is a provirus?
- A. Free virus
- B. Free DNA
- C. Primitive virus
- D. Integrated viral genome
Explanation: The correct option is D, as a provirus is the form of a retrovirus that is integrated into the host cell's DNA.
Correct answer: Integrated viral genome- A. Protection against the viral genome from physical and enzymatic destruction.
- B. Providing binding sites that enable the virus to attach to specific receptor sites on the host cell.
- C. Serving as a vehicle of transmission from one host to another.
- D. All of the above
Explanation: The viral capsid is a protein shell that protects the viral genome from damage and enzymatic degradation, allows the virus to attach to…
Correct answer: All of the above- A. Adenovirus
- B. Herpes virus
- C. Poliovirus
- D. None of these
Explanation: The correct option is B, as out of all the above-mentioned viruses, only the herpes virus is an enveloped virus, as it has a lipid…
Correct answer: Herpes virus- A. Virus containing single strand DNA
- B. Virus containing double strand DNA
- C. Virus containing single strand RNA
- D. Virus containing single strand RNA and single strand DNA
Explanation: Option D is correct, as viruses can be classified into two groups based on their genetic material: DNA viruses and RNA viruses.
Correct answer: Virus containing single strand RNA and single strand DNA- A. Centimeters
- B. Micrometers
- C. Nanometers
- D. Millimeters
Explanation: Viruses are microscopic organisms measured in nanometers. They can range from 20 nm to 400 nm.
Correct answer: Nanometers- A. 20
- B. 30
- C. 10
- D. 40
Explanation: Fact: The capsomeres are arranged in 20 equilateral triangles in icosahedral viruses.
Correct answer: 20- A. Having capsid
- B. Having DNA
- C. Having RNA
- D. Having small size
Explanation: The correct option is A. A capsid is a protein coat that surrounds the genetic material of a virus.
Correct answer: Having capsid- A. Capsid has capsomeres
- B. Both DNA and RNA together as genome
- C. Some are enveloped
- D. Many infect animals
Explanation: Viruses cannot have both DNA and RNA as their genome because each type requires a completely different replication strategy and enzymes.
Correct answer: Both DNA and RNA together as genome- A. Free living
- B. Obligate parasites
- C. Both A and B
- D. None of the above
Explanation: Option B is correct. Viruses are obligate parasites. This means that they can only survive and reproduce inside living cells.
Correct answer: Obligate parasites- A. Capsomeres
- B. Size of virus
- C. Whole capsid
- D. Internal proteins
Explanation: The antigenicity of a virus is mainly determined by its whole capsid, as the capsid surface exposes epitopes recognized by the immune…
Correct answer: Whole capsid- A. TMV
- B. T4 Phage
- C. Poxvirus
- D. Herpes virus
Explanation: Tobacco mosaic virus (TMV) is a well-studied plant virus that belongs to the Tobamovirus genus.
Correct answer: TMV- A. Capsid
- B. Matrix protein
- C. Envelope
- D. Nuclear capsid
Explanation: In viruses, the matrix protein is a structural protein located between the nucleocapsid and the viral envelope.
Correct answer: Matrix protein- A. DNA-enveloped virus
- B. RNA-enveloped virus
- C. DNA naked virus
- D. RNA naked virus
Explanation: The correct option is D.An RNA-naked virus is a virus that has an RNA genome but no envelope.
Correct answer: RNA naked virus- A. Herpes virus
- B. Reovirus
- C. Polio virus
- D. Papillomavirus
Explanation: Among all of the above options, only herpes is an enveloped virus. All the rest are non-enveloped.
Correct answer: Herpes virus- A. Hexagonal capsomeres
- B. Pentagonal capsomeres
- C. Triangular Capsomeres
- D. Both A and B
Explanation: An icosahedral shape, common in viral capsids, is made of protein subunits called capsomeres, which can be pentameric (five subunits) or…
Correct answer: Both A and B- A. Can only replicate in certain types of cells.
- B. Certain cells are susceptible to viral infection.
- C. They can only enter cells that have proper/specific receptors.
- D. They can only enter cells with glycoproteins.
Explanation: Viruses have a limited host range because they cannot infect all cells.
Correct answer: They can only enter cells that have proper/specific receptors.