Evolution, Viruses, and Prokaryotes Flashcards
Prion
Misfolded protein which causes a chain reaction leading to more misfolding. Examples: Mad cow, Kuru, Creutzfeldt-Jakob, Chronic Wasting Disease, Scrapie, Feline Spongiform Encephalopathy, Zoo animal encephalopathy, etc
Nucleoid
Complex of RNA, DNA and proteins in prokaryotes that forms a structure visible under light microscope
Virulent Virus
Virus capable of causing disease
Virus in lytic cycle

viral envelope
A membrane that encloses the capsids of some viruses. Normally includes specialized proteins that attach to host-cell surfaces.
Enveloped viruses form envelopes from the host cell which protect against detection by the immune system.
Host cell may not die from lysis, but will die from degrading cellular membrane
Kingdoms in Eukarya
Protista, Fungi, Animalae, Plantae
Phylogeny refers to
evolutionary relationships that are based on shared characteristics including physical traits, genetics, and behavior
Speciation
Members from a single species have evolved into different groups that can no longer produce fertile offspring
Gene pool
Total of all alleles in a population

Bacteriophage
a virus that infects and replicates within bacteria
Bacteriophage are composed of proteins that encapsulate a DNA or RNA genome, and may have relatively simple or elaborate structures.
many of the most complex capsids
Injects nuclei acids into host cell through tail
Viral enzymes digest hole in cell wall
Host cell in viral infection
Cell that is being infected
Lysogenic infection:
In a lysogenic infection, the viral DNA is incorporated into the host genome, or, if the virus is an RNA virus and it possesses the enzyme reverse transcriptase, DNA is actually reverse-transcribed from RNA and then incorporated into the host cell genome. When the host cell replicates its DNA, the viral DNA is replicated as well. A virus in a lysogenic cycle is called a temperate virus.
A host cell infected with a temperate virus may show no symptoms of infection. While the viral DNA remains incorporated in the host DNA, the virus is said to be dormant or latent, and is called a provirus (a prohage if the host cell is in a bacterium). the dormant virus may become active when the host cell is under some type of stress. ultaviolent light or carcinogens also may activate virus. When the virus becomes active, it becomes virulent.
Provirus or Prophage
Virus incorporated into host DNA
RNA-dependent RNA polymerase (RdRP)
Enzyme that can synthesize new RNA from template RNA. Makes either RNA+ from RNA- or vice versa
RNA+ encodes for proteins
RNA- complimentary strand that cannot encode for protein
Viruses preferentially carry either RNA+ or RNA-
Ontogeny recapitulates phylogeny?
Embryonic development retraces the steps of evolutionary history
Latent period with viral infection
Period from infection to lysis
Retrovirus
ssRNA virus that transcribe RNA into dsDNA by using reverse transcriptase (carried by retrovirus)
Example: HIV
Virus
Tiny infectious agents that usually lack cellular machinery to reproduce and leverage the transfer of genetic information to cells to reproduce. Not considered living. Can contain DNA or RNA
Known as viral particle or virion as mature virus outside of host
Can be thought of as a eukaryotic nucleus
Natural selection
Genes that are advantageous in environment are preferentially passed down from generation to generation
Random Mating
Organisms are equally likely to mate with each other regardless of their phenotype
Taxonomical Classification System
Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species
Prokaryotes
single-celled organism that lacks a membrane-bound nucleus (karyon),mitochondria, or any other membrane-bound organelle.
Two domains- Archaea and Bacteria
