Term
| True or False: T4 bacteriaphage is non-lytic |
|
Definition
|
|
Term
| How does T4 replicate and why? |
|
Definition
|
|
Term
| What is a lytic bacteriaphage? |
|
Definition
| Infects the host, replicates, then lyses the host |
|
|
Term
| What is a lysogenic bacteriaphage? |
|
Definition
It integrates itself into the host chromosome
- does this by site-specific recombination at homologus attachment sites |
|
|
Term
| Does lambda replicate by a lytic or lysogenic pathway? |
|
Definition
|
|
Term
| What is the integrated form of the lambda phage? |
|
Definition
|
|
Term
|
Definition
| Circular DNA molecules often found in bacteria, and can replicate independently of the bacterial chromosome |
|
|
Term
| What type of plasmid contain genes that can provide resistance to antibiotics? |
|
Definition
|
|
Term
| What type of plasmids contain genes that allow gene transfer by conjugation? |
|
Definition
|
|
Term
| What are the three mechanisms of gene transfer in bacteria? |
|
Definition
| Transformation, conjugation, and transduction |
|
|
Term
|
Definition
| It is the uptake of free DNA through the cell wall; is sensitive to DNase |
|
|
Term
|
Definition
| The transfer of DNA from one bacteria to another through a conjugation pore |
|
|
Term
| True or False: It requires cell contact |
|
Definition
|
|
Term
|
Definition
| Infection with a virus; does not require cell-cell contact; not sensitive to DNase |
|
|
Term
| True or False: Transformation occurs in all bacteria |
|
Definition
|
|
Term
| What is required for transformation? |
|
Definition
| Formation of a receptor/channel complex |
|
|
Term
| What happens in transformation? |
|
Definition
| One strand is degraded, and the other strand undergoes homologous recombination with the host chromosome |
|
|
Term
| What is required for conjugation? |
|
Definition
| A fertility factor which is a genetic element that encodes genes required for conjugation |
|
|
Term
| Where would a fertility factor be found? |
|
Definition
| On a plasmid in F+ cells; or incorporated into the host Hfr cells |
|
|
Term
|
Definition
| They pull the recipient cell to the donor cell and form a conjugation channel? |
|
|
Term
| How does replication work in conjugation? |
|
Definition
- Donor DNA is cut at oriT site\
- one strand is transferred to the recipient cell where the second strand is synthesized (rolling circle mechanism) |
|
|
Term
| What is required for transformation? |
|
Definition
| Formation of a receptor/channel complex |
|
|
Term
| What happens in transformation? |
|
Definition
| One strand is degraded, and the other strand undergoes homologous recombination with the host chromosome |
|
|
Term
| What is required for conjugation? |
|
Definition
| A fertility factor which is a genetic element that encodes genes required for conjugation |
|
|
Term
| Where would a fertility factor be found? |
|
Definition
| On a plasmid in F+ cells; or incorporated into the host Hfr cells |
|
|
Term
|
Definition
| They pull the recipient cell to the donor cell and form a conjugation channel? |
|
|
Term
| How does replication work in conjugation? |
|
Definition
- Donor DNA is cut at oriT site\
- one strand is transferred to the recipient cell where the second strand is synthesized (rolling circle mechanism) |
|
|
Term
| How can chromosomal genes be mapped? |
|
Definition
| By interupting mating b/w Hfr and F- cells |
|
|
Term
|
Definition
| Excision of an F factor from an Hfr cell, which transfers host DNA to the F plasmid. |
|
|
Term
| What is general transduction? |
|
Definition
| Random bits of host DNA are encapsulated into a phage coat and transferred to a recipient cell |
|
|
Term
| What is specialized transduction? |
|
Definition
| The lambda prophage can occur anomalously |
|
|
Term
| What causes the inclusion of flanking chromosomal DNA? |
|
Definition
|
|
Term
|
Definition
| A DNA sequence that can change its position in the genome |
|
|
Term
|
Definition
| An insertion sequence which acts as a small transposon |
|
|
Term
| What are composite elements |
|
Definition
| IS elements that are close together, and when transposed (relocated) take the DNA sequence that's in between, with them |
|
|
Term
| What are IS elements made of? |
|
Definition
| terminal inverted repeats & an intervening sequence |
|
|
Term
| What does the intervening sequence of an IS element do? |
|
Definition
| encodes the transposase gene |
|
|
Term
| How does transposition work? |
|
Definition
-IS is removed from original site
-a staggered cut is created in the new site
-IS element is inserted
-gap is filled |
|
|
Term
| What are replicative transposons? |
|
Definition
Tn3
-donor and recipient elements are fused, the transposon is replicated, recombined and then released
-results in the duplication of the transposon |
|
|
Term
| What kind of transposons are found in bacteria? |
|
Definition
| composite elements (IS elements) and replicative transpons |
|
|
Term
| What kind of transposons are found in eukaryotes? |
|
Definition
| cut and paste elements (Ds) elements, retiroviruslike elements |
|
|
Term
| Why do Ds elements require an Ac element to encode the transposase gene? |
|
Definition
| Ds elements don't have the transposase gene |
|
|
Term
| What are retroviruslike elements |
|
Definition
| Genetically similar to retroviruses but dont have the genes needed to spread outside of the cell |
|
|
Term
| How do retroviruses transpose? |
|
Definition
1.transcription of the retroviruslike element
2. Reverse transcription of the RNA into DNA
-insertion of the DNA into a new position in the genome |
|
|
Term
| What are the two kinds of retrotransposons? |
|
Definition
|
|
Term
| What kind of organisms have retrotransposons? |
|
Definition
|
|
Term
| What are retrotransposons lacking? |
|
Definition
|
|
Term
| How are retrotransposons formed & re-inserted into the chromosome |
|
Definition
-transcribed from their own promoters by RNA pol II
-reverse transcribed into DNA
-inserted into chromosome |
|
|
