virus chapter

Bacteriophages specifically infect bacterial cells by attaching to receptors on the bacterial cell wall.

Tobacco Mosaic Virus causes mosaic-like discoloration on tobacco and several other plant leaves, reducing crop yield.

DNA viruses contain DNA as their genetic material, whereas RNA viruses contain RNA. A virus never contains both DNA and RNA simultaneously.

Bacteriophages are highly specific viruses that infect bacteria and cannot infect plant or animal cells.

Viral glycoproteins embedded in the envelope recognize host receptors and facilitate membrane fusion during infection.

Naked viruses lack a lipid envelope, making them more resistant to drying, acids, and detergents than enveloped viruses.

Poliovirus infects motor neurons and may cause poliomyelitis, leading to paralysis in severe cases.

Baltimore Group III viruses contain double-stranded RNA genomes and require viral RNA-dependent RNA polymerase for replication.

Coronaviruses possess one of the largest positive-sense single-stranded RNA genomes among viruses.

TMV has a rod-shaped appearance due to its helical arrangement of capsid proteins around the RNA genome.

Complex viruses, particularly bacteriophages, possess specialized structures like heads, tails, and tail fibers for host attachment.

Human Papillomavirus infects epithelial tissues and is responsible for warts and cervical cancer.

Negative-sense RNA cannot be translated directly. It must first be converted into positive-sense RNA by viral RNA-dependent RNA polymerase.

Adenoviruses possess a linear double-stranded DNA genome enclosed in an icosahedral capsid.

Viruses contain either DNA or RNA as their genetic material, never both. This is the most fundamental basis of viral classification.

Adenovirus is a classic example of a naked virus with an icosahedral capsid, making it highly resistant to environmental conditions.

Retroviruses, such as HIV, possess ssRNA and the enzyme reverse transcriptase, enabling synthesis of DNA from RNA.

Rabies virus has a bullet-shaped appearance but internally possesses a helical nucleocapsid.

Bacteriophages are viruses that specifically infect bacteria and play important roles in bacterial genetics and biotechnology.