exam 2 Bacterial and viral gentic system Flashcards
freely replicating plasmids are called
Episomes
Describe bacterial genome
mostly single, circular DNA molecule/chromosomes
these are extra chromosomes, small circular dna that sometimes integrate into genome
plasmids
What are ways to transfer gene in Bacteria
COnjugation
Transformation
Transduction
This direct transfer of DNA from one bacterium to another
Conjugation
In this way, the bacterium takes up free DNA from the medium
Transformation
This way, bacterial viruses take DNA from one bacterium to another
Transduction
Is conjugation a reciprocal exchange of genetic information TRUE/FALSE
False
sex pilus is a
connection tube
F+ cells
donor cells containing F factor
F- cells
recipient cells lacking F factor
Antibiotic resistance comes from
the action of genes located on R plasmids.
Is antibiotic resistance a natural gene transfer or artificial
natural gene
Is the transfer of R plasmiods restricted to bacteria of the same or even related species
no, it is not
which cell takes up DNA
Competent cells
which cells that receive genetic material
transformants
which cells that are transformed by two or more genes
cotransformed
What is the name of the small infectious agent that only replicates INSIDE the living cell of another organism
Virus
Describe the genome of Virus
can be dna or RNA, single or double strand
What does it means for a virus to be sometimes enveloped
it means they are wrapped in a small piece of the host cells’ membrane
How does transformation work
a bacterium takes up DNA from the medium
How do virulent phages reproduce
through lytic cycle and always kills the host cells
An example of bacterial infection virus?
bacteriophage
Which phage phages DNA integrates into bacterial chromosome where it remains as inactive prophage?
Lysogenic phages
Lysogenic phages are also known as
Temperate phages
Lytic cycle process
- The phage binds to the bacterium
- The phage DNA enters the host cell
- The host DNA is digested
- Phage DNA replicates
- The host cell transcribed and translates the phage, producing phage protein
- Assemble of new phage is complete. A phage encoded enzyme causes cell to lyse
Lysogenic cycle process
- The phage binds to the bacterium
- The phage DNA enters the host cell
- The phage DNA integrates into the bacterial chromosomes and becomes a prophage
- The prophage is replicated as part of the bacterial chromosome. This replication can continue through many cell divisions.
- The prophage may separate from the chromosome and the cell will enter the lytic cycle.
Which comes first lysogenic/ lytic cycle
lysogenic process then lytic cycke
What are the steps in the CRISP-Cas immunity
1, Adaptation
2. Expression
3. Interference
Does HIV retrovirus have a dormant phase
yes
Characterictics of Retrovirus
- RNA genome
- Reverse transcriptase synthesizes DNA from RNA template
- HIV is an example
What phases does a herpes virus have
latent and lytic phases
Describe process of infection in herpes virus
Double stranded DNA enveloped virus
Infects epithelial cells, then associated sensory neurons
Viral latent phase is in neurons where viral is episomal
Varoety of factors reintiate lytic phase
What type of strand is Influenza
Single stranded negative sense RNA genome
Most cases of influenza A is divided into
hemagglutin (HA) and neuraminidase(NA)
Mutation isn Influenxa can result in antigenic shift or antogenic drift
antigenic shift
which replication is error prone
INfluenza
What type of changes result in antigenic shift
big changes, more than one type of influenza virus infects a single cell producing hybrid virus.
which animal harbor most viruses
Birds
SWINE can be infected by?
bird and human strains
Is there a reciprocal exchange of gene material in Conjugation
no, DNA is transferred only from donor to recipient
Which type of continual change is new mutation continually introduced into the genome of each viral strain
antigenic drift
Which type of change is major in which genetic material from different strains is combined in a process
Antigenic shift
