Chapter 1, 2, 3, and 4 exam review Flashcards
Viruses are composed of what?
Nucleic acids and proteins
Viruses are acellular which means what?
That they have no organelles.
Why does parasitic means?
They must infect the host in order to reproduce
Why do viruses do not have all the characteristics of life?
Because they cannot metabolize or grow.
Viruses evolutionary pathways unclear but they can?
Mutate and evolve.
Define viron?
They are single virus particle; their basic structure are Nucleic acids.
What are capsids?
Protein external covering.
What are the four main shapes of viruses?
- ) Filaments: long and cylindrical
- ) Isometric: spherical
- ) Envelope: extra membrane surrounding the capsid
- ) Head and tail
What are DNA viruses?
DNA directs host cells replication. It makes new copies of viral genome and then transcribe and translate the viral protein.
What do RNA viruses do?
Makes enzymes that can replicate RNA into DNA.
What is a genome?
It only needs the genetic info to create proteins not present in host cell.
The virus classification system is also called the what?
Baltimore classification, which look at genetic info on how the mRNA is created and the structure of the capsid.
The classification has how many groups?
7
What is a replication?
DNA making DNA
What is transcription?
DNA making RNA
What is translation?
RNA making proteins.
What are the four steps of a virus infection?
- ) Attachment
- ) Entry
- ) Replication
- ) Egress
What is attachment?
Virus will bind specific receptors
What is entry?
Genetic info will enter host cell the capsid remains outside.
What is replication and assembly?
Virus incorporates its genetic info into host cell and uses host cell to create new virons.
What is egress ?
Releases new virons from host cell
What is cell death?
Apoptosis
What is bacteriophage?
Virus that infect bacteria.
How do animal cells affect the host?
They enter through receptor mediated endocytosis.
How do plant cell viruses affect the host?
They are transmitted through damage to the plant. It penetrates the cell wall. Infected cells may commit suiccide to prevent spread.
How do vaccines help build immunity?
Viruses help build immunity through live or dead viruses
What is more effective live or dead viruses?
Live vaccines are more effective, however there is a small chance they can mutate to become infectious
What is the lyric phase?
The viruses created, immediately released and then the bacteria cell bursts.
What is the lysoggenic phase?
The virus DNA is incorporated into bacteria .
What is endocytosis
Vesicles transports out to in
What is horizontal transfer?
Viruses enter plant through damaged tissue.
What is vertical transmission?
Parent plant passes the virus to offspring through reproduction.
Define prokaryotes?
Are singled organisms with no internal organelles that just group together.
What are microbial mat?
Mixture of bacteria and Archae. Multiple layers of cells held together with extra cellular matrix.
What does anaerobic mean?
Does not use oxygen.
What is Cyanobacteria?
They was the first to use oxygen.
What are extremophiles?
A group that lives in extreme conditions.
What is a Biofilm?
A community of micro organisms. Example would be your teeth.
What are the five kingdoms scientist grouped living things?
Animals, plants, fungi, protists, prokaryotes.
Carl Woese and other scientist proposed what?
That all life on Earth evolved along three lineages, called domains.
What are the three domains?
Bacteria, Archaea, and Eukarya.
Which two of the three domains are prokaryotic?
Bacteria and Archaea.
What is the preferred condition of acidophiles?
A pH of 3 or below.
What is the preferred condition for growth for alkallphiles?
A pH of 9 or above
What is the preferred condition of thermophiles?
A temperature of 60 to 80 degrees Celsius.
What is the preferred condition for hyperthermophiles?
80 to 122 degrees Celsius
What is the preferred condition of pyschrophiles?
15 to 10 degrees Celsius or lower