Consider the following statements:
I. No virus can survive in ocean waters.
II. No virus can infect bacteria.
III. No virus can change the cellular transcriptional activity in host cells.
Which of the statements given above are correct?
Detailed Explanation:
All three statements are incorrect because viruses are found in diverse environments, can infect bacteria, and can manipulate host cell functions.
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Statement I is Incorrect: Viruses are extremely abundant in oceans and play an important role in marine ecosystems.
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Statement II is Incorrect: Certain viruses called bacteriophages specifically infect bacteria.
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Statement III is Incorrect: Viruses can alter the host cell's transcriptional machinery to produce viral proteins and replicate themselves.
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Therefore, none of the statements are correct, making Option D the correct answer.
Statement-wise Analysis
| Statement | Status | Explanation |
|---|---|---|
| I. No virus can survive in ocean waters | ❌ Incorrect | Oceans contain billions of viruses and are one of the largest viral reservoirs on Earth. |
| II. No virus can infect bacteria | ❌ Incorrect | Bacteriophages are viruses that infect bacteria. |
| III. No virus can change cellular transcriptional activity | ❌ Incorrect | Viruses frequently modify host gene expression to support their replication. |
Viruses
What are Viruses?
Viruses are microscopic infectious agents that can reproduce only inside living host cells.
Important Facts
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Found in soil, air, freshwater, oceans, and living organisms.
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Cannot reproduce independently.
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Use host cell machinery to make new viruses.
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Can infect animals, plants, fungi, and bacteria.
Bacteriophages
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Viruses that infect bacteria.
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Among the most abundant biological entities on Earth.
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Widely used in biotechnology and phage therapy research.
How Viruses Affect Host Cells
Viruses can:
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Alter gene expression.
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Hijack cellular machinery.
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Suppress immune responses.
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Change transcription and protein synthesis pathways.
Question 1 of 10 Microbiology
Practice PYQ questions from this topic across all years
First question in this topic
Consider the following statements: Some microorganisms can grow in environments wi...