exam 3 Flashcards
(39 cards)
compare lytic replication and lysogeny
Both produce viruses in the end
lysogeny
– Modified replication cycle in which the viral DNA is incorporated into the DNA of the host cell
– Infected host cells grow and reproduce normally for generations, thereby amplifying the phage DNA
– Eventually, environmental stress causes the phage to excise and enter the lytic cycle
lytic replication cycle
Attach Entry Synthesis assembly Release
– Replication cycle usually results in death and lysis of host cell
viral lyptic replication
compare mitosis and meiosis
Both processes include the breakdown of the nuclear membrane
• Mitosis = Replication division
- Chromosomes are copied, then separated to 2 nuclei
- 1 sequence of nuclear division with 4 phases (prophase, metaphase, anaphase, and telophase)
- Asexual reproduction
- 1 diploid nucleus → 2 identical, diploid nuclei
• meiosis= Reduction division
Chromosomes are copied once, then separated in 2 division events: meiosis I and meiosis II
– 1 diploid nucleus → 4 non-identical, haploid nuclei; unidentical from crossing over
– sexual reproduction
pour plate method
CFUs are separated from one another using a series of dilutions. An initial 1mL sample is mixed into 9.0 mL of medium in a test tube. After mixing, a new sample from this medium is then used to inoculate 2nd tube of liquid medium. The process is repeated to establish a series of dilutions.
compare pour plate and streak plate method
The goal for both is to come up with a pure culture
streak plate method
The back loop of an inoculum is spread across the surface of a petri dish in a streak pattern. The loop is sterilized by flame between streaks. The set of (4) streak patterns gradually dilute the sample to a point that CFUs are isolated from one another
the process by which bacteriophages carry genes that are expressed in the bacterium and cause human disease
Lysogenic conversion
human prion disease
variant Creutzfeldt-Jakob Disease (vCJD)
Proteinaceous infectious agents
Prions
viruses cause what % of human cancers
20-25%
What is a bacteriophage? Which bacteriophage is the model for studying the viral infection process for bacteria?
Bacteriophage (viruses that eat bacteria) = “bacteria eater”.; Bacteriophage T4
tiny infectious acellular agent with nucleic acid surrounded by a protein covering called a capsid
virus
extracellular form of a virus
viron
*the motile feeding form of a protoza
tropozoite
culture refers to a pure culture
axenic
genus that causes the disease UTI
Pseudomonas
genus that causes listerosis and contaminates dairy and meat products
listeria
genus that causes cholera; characteristics: facultatice anaerobes, curved rods, polar flagells
Vibrio
causes tetanus; forms endospores
clostridium
causes NO disesas; worlds toughest bacterium
deinococcus
