SCIENCE
VIRUS AND BACTERIA
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Viruses contain DNA as their nucleic acid and are always round
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Viruses contain DNA or RNA and are always surrounded by an envelope
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Viruses always contain RNA and usually have tail fibers
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Viruses contain DNA or RNA and are always surrounded by a capsid
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Detailed explanation-1: -All viruses are obligate parasites; that is, they lack metabolic machinery of their own to generate energy or to synthesize proteins, so they depend on host cells to carry out these vital functions.
Detailed explanation-2: -which of the following statements about viral structure is true? Option (d) Glycoproteins help the virus attach to the host cell. All the virions have the nucleic acid genome which is covered with an outer protein protective layer is termed as capsid.
Detailed explanation-3: -Viruses are smaller and simpler in construction than unicellular microorganisms, and they contain only one type of nucleic acid-either DNA or RNA-never both.
Detailed explanation-4: -The simplest virions consist of two basic components: nucleic acid (single-or double-stranded RNA or DNA) and a protein coat, the capsid, which functions as a shell to protect the viral genome from nucleases and which during infection attaches the virion to specific receptors exposed on the prospective host cell.