chapter 19: viruses

protein enclosing viral genome

membrane surrounding the viral capsid, made from host membrane and viral parts

virus that infects bacteria

reproductive cycle of viruses which results in host cells being destroyed and releasing progeny viruses

reproductive cycle resulting in viral genome being engrained into host cell, letting the host cell continue living and viral genome being passed onto daughter cells. creates prophages

virus that only uses lytic cyclet

virus that can use lytic and lysogenic cycle

result of lysogenic cycle

viral DNA in host DNA as a permanent part of it

a nonliving because it requires other cells for duplication

• elongated capsid head that contains genome

• protein tail piece used to inject genetic info into host

environmental conditions control this. if the environment is stressful (starvation or toxic chemicals) will cause virus to use lytic cycle

allows for host cell to live

• DNA or RNA

• single or double stranded

virus will use reverse transcriptase to incorporate viral RNA in host DNA

used by retroviruses to put viral genome in host DNA

• a new virus

• from mutations, dissemination from isolated human pop., or transferred from different species

circular RNA molecule that infects plant cells and affects growth

slow-acting, virtually indestructible infectious protein. propagates by turning normal proteins in prions

• hard to detect

• brain disease

• don’t know you have until too late