Ch. 10 Molecular Biology of the Gene – 10.22

What are two ways in which bacteriophage can reproduce? Lytic cycle: Lysis or breaking open of the cell Lysogenic cycle: inserts its DNA into a chromosome of the host cell, which will replicate both the virus and its own DNA.

An influenza virus, aka: “the flu” has RNA rather than DNA. What is the purpose of RNA? Serves as template for making more viral-genome RNA & mRNA for synthesis of new viral-proteins What is the purpose of the glycoprotein spikes? Helps virus enter and leave cells Other RNA viruses include the common cold, measles & mumps. DNA viruses include hepatitis, chicken pox & herpes.

How does a virus reproduce without having DNA polymerase or ligase? Virus uses that infected cells organelles to reproduce (HIJACK) RNA is replicated inside the host cell by special enzymes encoded by the virus. Viral RNA serves as mRNA for synthesis of viral proteins.

In what ways do Viruses enter humans? Lesions or bodily fluids, insects, contaminated foods & surfaces How do they get into plant cells? Lesions caused by injury Transfered from insects feeding on them Contaminated farming or gardening tools

Mutations of existing viruses is a major source of new viral diseases. Why is this dangerous? Cause disease in people with immunity to the old virus. Come from animals (Give example…chirp chirp) Start isolated and spread suddenly (AIDS)

HIV has some special twists to it such as? Membrane envelope like mumps to leave the cell (disguised) 2 strands of RNA HIV is a retrovirus…what is that? Retrovirus – reverse transcription because of reverse transcriptase (RNA to DNA)

How can a retrovirus make DNA from RNA? Uses RNA as template to synthesize DNA from its RNA genome, sends DNA into cell nucleus What’s a provirus? Foreign DNA inserted into your DNA… Can be transcribed, translated to viral proteins. New viruses are made & leave cell to infect and reproduce in other cells.

What do you think are all the blue dots on the red blob? HIV attacking the white blood cells killing them, and weakening your immune system.