AP Bio - Unit 6: Gene Expression and BioTechnology (Viruses)

what is a virus

what is a virus

genetic informtion (DNA or RNA) wrapped in a protein coat. many are harmless, some are deadly

types of prokaryote viruses (bacteriophages)

virulent phages and temperate phages (only affect bacteria)

virulent phages

preform the lytic cycle in which they attack to the bacteria and insert their viral DNA to be sequenced by the cell until it lyces

temperate phages

goes through the lysogenic cycle in which it inserts it genome into the host. when the host duplicates, so does it. it waits in the host until it senses danger and tries to escape via the lytic cycle

eukaryote viruses

DNA viruses, RNA viruses and RNA Retroviruses. they affect us, could be single or double stranded and have a lipid layer

DNA viruses

goes through lysogenic cycle, doesnt mutate much because od DNA proofreading system in eukaryotes

examples: herpes, smallpox, chickenpox

RNA viruses

preform lytic cycle, mutate frequently because there is no proofreading

examples: common cold, flu, covid-19

RNA retroviruses

converts their RNA into DNA using Reverse Transcriptase to embed their DNA into ours

example: HIV

transposons

genes that copy and paste themselves to other areas of the genome

how to viruses form

antigenic shift and antigenic drift

antigenic shift

mixing of genes from different viruses(fast) (bacterial transfer)

antigenic drift

accumulation of mutations (slow)