🏷️ LIMITED TIME OFFER: GET 20% OFF GRADE+ YEARLY SUBSCRIPTION →
Log in
Biology
3
answers
0
watching
104
views

An Hfr strain is an E. coli strain in which the F plasmid isintegrated into the chromosome. How does an Hfr cell replicate itsDNA? (under which condition, it uses the theta structure? Underwhich condition, it uses the rolling circle mode?)

Watch
3
answers
0
watching
104
views

For unlimited access to Homework Help, a Homework+ subscription is required.

Unlock all answers

Get 1 free homework help answer.
Already have an account? Log in
Share
Already have an account? Log in
Share
Casey Durgan
Casey DurganLv2
29 Sep 2019
Already have an account? Log in
Share

Related textbook solutions

Molecular Cell Biology
8 Edition,
Lodish
ISBN: 9781464183393
Biology: Science for Life with Physiology
6 Edition,
Belk
ISBN: 9780134555430
Concepts of Biology
OER Edition,
Openstax
ISBN: 9781938168116
Biology
2nd Edition, 2013
Openstax
ISBN: 9781947172517
Essentials of Biology
5 Edition,
Mader
ISBN: 9781259660269

Related questions

A. What is the problem during replication at the end of a linearchromosome?


B. How can a DNA polymerase use a protein as a primer forreplication?


C. Why is a rolling circle model of replication advantageous forviral replication but not bacterial replication?


D. What happens to a virus that uses the rolling circle model ofreplication but has no means to cut monomers at discrete sites andcuts only unit lengths?


E. How can an integrated F factor be used to map the bacterialchromosome?


F. Why do recipients from an Hfr mating rarely become Hfr?


G. Why don't multicopy plasmids use the same kind ofpartitioning system as single-copy plasmids?


H. How does one plasmid know whether or not another plasmid isin the same family?


I. How is crown gall disease similar to cancer in humans?


J. What features of the Ti plasmid make it attractive to use asa system to transfer genes into plants?


H. Why is the mitochondrial replication system not identical toeukarotic nuclear replication?

Hfr Mapping Problem

An Hfr E. coli contains the following genetic traits: kans, lac+ , his+ , trp+ , ampr . It is mated with a recipient E. coli that contains the opposite genetic traits for those traits listed abov: kanr. lac- , his- , trp- , amps . Assume all other catabolic and biosynthetic genes are present in both strains. Note that kanS means the absence of the kanamycin resistance gene in the Hfr strain, which will allow growth only of the recipient cells in the presence of kanamycin. This is necessary to select against the Hfr donor strain as you are monitoring which genes transferred to the recipient.

At periodic intervals, conjugation is disrupted and cells are plated onto several types of defined media. Nothing grows at the beginning of the experiment on media containing lactose, kanamycin, and ampicillin as this is the most selective medium, but all cells grow on complex media containing no ampicillin (the least selective medium). Mating is interrupted at the times listed below and the following are some of your observations of growth characteristics on a few of the selective media plates containing the indicated nutrients/antibiotics:

15 min.

Growth on defined media containing: kanamycin, glucose, histidine (does not contain tryptophan).

No growth on defined media containing: kanamycin, lactose (sole carbon source), tryptophan, histidine.

30 min.

Growth on defined media containing: kanamycin, lactose (sole carbon source), histidine (does not contain tryptophan).

No growth on defined media containing: kanamycin, glucose, tryptophan (does not contain histidine).

No growth on defined media containing: kanamycin, ampicillin, lactose (sole carbon source), histidine, tryptophan.

45 min.

Growth on defined media containing: kanamycin, lactose (sole carbon source) (does not contain histidine or tryptophan).

No growth on defined media containing: kanamycin, ampicillin, lactose (sole carbon source), histidine (does not contain tryptophan).

60 min.

Growth on defined media containing: kanamycin, lactose (sole carbon source) (does not contain histidine or tryptophan).

No growth on defined media containing : kanamycin, ampicillin, lactose (sole carbon source) (does not contain histidine or tryptophan).

Multiply questions here

Q2. What is the consequence of chromosome inversion on meiosis? (work on a zygote with one normal chromosome and one chromosome with an inversion)

Q3. Search the web or read the textbook. Find a disease that is caused by translocation. What kind of translocation causes the disease?

Q4. Briefly explain how down’s syndrome or other trisomy is generated (3 sentences should be enough for you to explain this clearly)

Q5. I mutated a culture of wild type E. coli cells and wanted to isolate mutants that are unable to synthesize uracil (a nitrogen base in RNA). How can I achieve my goal? (try to finish your answer in 2-3 sentences)

Q6. For the ura- mutant isolated in Q5, I want to convert it to URA+ by transformation. Please tell me how I can achive this transformation with 3 SIMPLE sentences

Q7. What is the difference and relationship between an Hfr cell and an F+ cell?

Q8. I want to set up a mating between an Hfr strain and an F- (ade- his- bio-) strain and detect bio+ recombinant. Please design the experiment for me. (What genotype for Hfr do you need to choose? How will you select your recombinant? etc).

Q9. I want to use phage T2 to transducer the wild type ADE2 gene from the wild type E. coli strain to an ade2- E. coli mutant. How can I do this experimentally? (please briefly describe the approach, not experimental details such as incubation for 10 min, etc).

Q10. We talked about recombination in both eukaryotes and prokaryotes. Are there any differences in these two recombination ? (what are they if there are?)

Q11. Whose (or what) experiment proves that DNA is the genetic material?

Q12. What knowledge did Watson and Crick use in constructing the DNA model?

Q13. How does the double helix model support the three major functions of genetic materials?

Q14. What is the major chemical force that holds DNA and histone together? Hydrogen bonds

Q15. If I label E. coli cells in an N15 medium overnight and chase cells in an N14 medium for 2 generations, what fraction of cells still carry the N15 label?

Q16. If a 1000 kilobase fragment of DNA has five evenly spaced replication origins and DNA polymerase moves at 1 kilobase per second, how many seconds will a cell take to produce two daughter molecules?

Q17. DNA polymerases catalyze the polymerization of nucleotides. Use the formula for enzyme catalyzed reaction (see the example) to describe DNA polymerases. Example: Enzyme Substrate A + substrate B -------------------ïƒ product c + product D Q8. During DNA replication, what is the direction of the growing strand?

Q18. For DNA synthesis in cells, why are there a leading strand and a lagging strand?

Q19. The following is the DNA sequence of a template strand. If the primase begins to synthesize primers from the middle ‘g’, what will the primer sequence be? (assuming the primer can be 8 nucleotides long) 5’ GACTCTAgGACTCCT 3’

Q20. Both DNA polymerase I and DNA polymerase III synthesize DNA during DNA replication. Please state the different roles they played during DNA replication.

Weekly leaderboard

Home
Homework Help 3,900,000
Biology 460,000
Start filling in the gaps now
Log in