Ask Question, Ask an Expert

+61-413 786 465

info@mywordsolution.com

Ask Biology Expert

problem 1: Five Hfr strains A though E are derived from a single F+ strain of E. coli. The following chart shows the entry times in minutes of the first five markers into an F- strain when each is used in an interrupted mating experiment.

a) Draw a map of the F+ strain, indicating the position of all the genes and the distance between them in minutes

1140_position of genes.jpg

problem 2: An ade+ arg+ cys+ his+ leu+ pro+ bacterial strain is known to be lysogenic for a new phage but the site of the prophage is not known. The bacterial map is:

1339_bacterial map.jpg

The lysogenic strain is used as a source of phage and the phages are used to infect a bacterial strain with the genotype ade- arg- cys- his- leu- pro-. After a short incubation samples of these bacteria are plated on six different selective media (see table below; – indicates that supplement was not added, + means it was added) but colonies grew only on media 3 and 5.

a) describe the genetic process that this illustrates.
b) Indicate on the map where the prophage is integrated.

502_bacterial map table.jpg

problem 3: In a generalize transduction experiment, phages are collected from the donor strain of E. coli (genotype cys+ leu+ thr+) and used to infect a recipient strain (genotype cys- leu- thr-). The initial plating is on media supplemented leu and thr. 100 colonies grow.

a) What are the possible genotypes of the colonies on the original plate?

b) The colonies from the original plate are replica plated on the media in the table below. Describe the genotypes that could theroretically grow on each of these media

c) Use the data in the table to:

  • Draw a map of the three genes and indicate which two are closer together.
  • State what the actual genotypes are on each plate.

Media supplement    Leu    thr    None
Number of colonies    5      56    0

problem 4: In a newly discovered organism the Histidine operon is negatively regulated. It contains the structural genes for the enzymes needed to synthesize Histidine and the repressor protein is also coded within the operon. In other words, the polycistonic mRNA molecules that codes for the other proteins needed to synthesize Histidine also codes for the repressor protein. Synthesis of this mRNA is controlled by a single operator regulating the activity of a single promoter. The Allosteric effector molecule for the repressor is the tRNA bound to Histidine. The tRNA is not coded for by the operon. A collection of mutants with the following defects is isolated.

a) Determine which of these would synthesize the enzymes for Histidine synthesis

b) Determine which would be cis-dominate mutations to the wild-type allele

c) Determine which would be cis-recessive to the wild-type allele in a partial diploid

  • The promoter can not bind to RNA polymerase.
  • The operator is mutated such that it will no longer bind the repressor.
  • The DNA binding domain of the repressor is mutated suich that it no longer binds to DNA.
  • The allosteric site of the repressor protein is mutated such that it no longer binds to tRNAHIS.
  • The  allosteric site is mutated such that is binds to the tRNA without His bound.

problem 5: You isolate a new strain of bacteria that cannot use any other sugar besides glucose. You clone the genes from this strain for the enzymes necessary to ferment arabinose and lactose and find these are completely wildtype. What gene would you test next?

problem 6: Below is a picture of the current model of the interaction between the lac repressor, CAP, and the DNA of the operators and promoter regions. The repressor is shown in pink, CAP is blue the operator DNA is in red and the CAP binding site is in Blue. The Shine Dalgarno sequences are shown in green. describe how the bending and looping of the DNA may affect the RNA polymerases ability to initiate transcription.

1238_lac repressor.jpg

Biology, Academics

  • Category:- Biology
  • Reference No.:- M9565

Have any Question? 


Related Questions in Biology

Question 1go outside during daylight hours to a natural or

Question 1. Go outside during daylight hours to a natural or semi-natural space (e.g., Burton's Pond, an urban park, your backyard). Sit still for 20 minutes and closely observe the plants and animals around you. Describ ...

Assignment 1 create at least a 350-word blog post in

Assignment 1: Create at least a 350-word blog post in Microsoft® Word in response to the following question: Female copperhead snakes have the ability to reproduce both sexually and asexually. In your opinion, which meth ...

What is the process of turning polynucleotides into

What is the process of turning polynucleotides into proteins?

In a cross between two heterozygous aa individuals what is

In a cross between two heterozygous (Aa) individuals, what is the likely percentage of the offspring that will be heterozygous

Calculate the concentrations at eqbm of h2co3 hco3- co32-

Calculate the concentrations at eqbm of H2CO3, HCO3-, CO32-, and H+ in a saturated aq solution of H2CO3 in which the original concentration of H2CO3 is 0.034M (Ka1= 4.3*10^-7, Ka2 = 4.8*10^-11)

1 identify the maternal homolog for both chromosome 1 and 2

1.) Identify the maternal "homolog" for both Chromosome 1 and 2 and then the paternal homologs. Arrange these chromosomes as you would expect to find them during  G 1  of  interphase. What is the haploid number of our ce ...

Question all cancers are characterized by uncontrollable

Question: All cancers are characterized by uncontrollable cell growth and division, and when untreated, may be fatal. Cancers that occur in childhood are usually more malignant than those developed later in life. 1) Why ...

Two true-breeding stocks of pea plants are crossed one

Two true-breeding stocks of pea plants are crossed. One parents has red, axial flowers and the other has white terminal flowers; all F1 individuals have red, axial flowers. The genes for flower color and location assort ...

The ch50 assay is a traditional clinical assay that

The CH50 assay is a traditional clinical assay that measures the function of complement components. In a CH50 assay patient blood is drawn and serum separated from it (serum has no cells). Patient serum is mixed with ant ...

Assignment on nutrition - q1 task you need to select 2

Assignment on Nutrition - Q1. Task: You need to select 2 different age groups of your choice. You will need to plan balanced meals with snacks for a day. Once you have laid out the meal plan you need to: Explain why the ...

  • 4,153,160 Questions Asked
  • 13,132 Experts
  • 2,558,936 Questions Answered

Ask Experts for help!!

Looking for Assignment Help?

Start excelling in your Courses, Get help with Assignment

Write us your full requirement for evaluation and you will receive response within 20 minutes turnaround time.

Ask Now Help with Problems, Get a Best Answer

Why might a bank avoid the use of interest rate swaps even

Why might a bank avoid the use of interest rate swaps, even when the institution is exposed to significant interest rate

Describe the difference between zero coupon bonds and

Describe the difference between zero coupon bonds and coupon bonds. Under what conditions will a coupon bond sell at a p

Compute the present value of an annuity of 880 per year

Compute the present value of an annuity of $ 880 per year for 16 years, given a discount rate of 6 percent per annum. As

Compute the present value of an 1150 payment made in ten

Compute the present value of an $1,150 payment made in ten years when the discount rate is 12 percent. (Do not round int

Compute the present value of an annuity of 699 per year

Compute the present value of an annuity of $ 699 per year for 19 years, given a discount rate of 6 percent per annum. As