Ask Biology Expert

The basic formula for mutation rate is: mutation rate= # mutation events/(gene x generation). consider a situation when a scientist measures the mutation rate in an organism over several generations. if the scientist observes 10 mutant organisms for a particular gene after 4 generations (assuming 100,000 individuals or 100,000 genes per generation), they might conclude that the mutation rate is 10/(100,000 +100,000 +100,000 +100,000) = 10/(4 x 100,000) =2.5 x 10^-5. however, this analysis neglects a crucial detail: that all the mutants may have originated from a single mutant early in the experiment. for ex, all 10 mutants might represent exactly the same mutation, perhaps due to the origination of this mutation in the parental generation. in such a case, we have to consider that only one mutation event has occured; then the true mutation rate would be 1/(4x 100,000) = 2.5 x 10^-6. apply this concept to the following ex:

E.coli are grown in minimal medium containing lactose as the only carbon source until their density is 10^4 cells/milliliter; so all cells must have the lac operon to survive and reproduce. one milliliter of these cells is then put into 20 milliliters of rich growth medium containing glucose instead of lactose, but now also containing acridine orange (an intercalculating mutagen). the cells are cultured for 1 hour, the length of time it takes for E.coli to complete two divisions (i.e., double four times) at 37 degrees C; so there have been 2 generations after 1 hour. the cells are then plated on agar plates containing chemicals that can induce the lac operon and turn blue in the prescense of B-galactose.

Fifty-eight white colonies (not turning blue) are observed and picked to identify pure clones of each. of these 58 strains, many of these strains are identicdal. in all, there are only 20 different mutations, so the 58 different strains must have initially started from 20 different cells at some stage of the 2 hour incubation.

a) what is the mutation frequency for the lacZ gene at the end of the experiment>?
b) what is the mutation rate for the lacZ gene?
c) what kind of mutations would you expect to be most frequently caused by the acriding orange?

Biology, Academics

  • Category:- Biology
  • Reference No.:- M927814

Have any Question?


Related Questions in Biology

Case study question -case study - mary 21 years old

Case Study Question - Case Study - Mary, 21 years old, presented to the hospital emergency department with an infected laceration on her left foot. Mary was at a beach resort four days ago, when she trod on a broken glas ...

Assignment -the upper-case blue letters are the 14th exon

Assignment - The upper-case, blue letters are the 14th exon (of 20) in the Hephl1 gene in mice. The lower-case (black) letters are from the flanking introns.  The highlighted bases indicate primers that may be used to ge ...

Question - a pure strain of mendels peas dominant for all

Question - A pure strain of mendel's peas, dominant for all seven of his independently assorting genes, was testcrossed. How many different kinds of gametes could the F1 PRODUCE?

Igfbp2 rbp4 and factor d post bariatric surgeryigfbp2 what

IGFBP2/ RBP4 and Factor D Post Bariatric Surgery IGFBP2 ( what the normal physiological action in the body? And how it affectedby obesity? andpost bariatric surgery?) RBP4 (what the normal physiological action in the bod ...

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 ...

Question - gene cloning a please write the steps to clone

Question - Gene Cloning a) Please write the steps to clone the protease gene from Bacillus strain whose genome sequence is not known. b) Express the protease gene to obtain the enzyme in high yield, please plan your prot ...

Instructions address each question below as it relates to

Instructions: Address each question below as it relates to the caw study given. A patient was brought to the Emergency Department by ambulance with two arrow wounds. One arrow is still in the patient on the left side; en ...

Use of molecular tools and bioinforrnatics in the diagnosis

Use of Molecular Tools and Bioinforrnatics in the Diagnosis Characterization of Enteric Pathogens from a Case Study Purpose: The purpose of this project is to familiarize the student with modern molecular tools and bioin ...

Experiment 1 staining video1 open the media player by

Experiment 1: Staining Video 1. Open the Media Player by clicking on the film-strip button in the lower left of the lab's window frame, as shown below. The Media Player is a repository of images, videos, saved snapshots, ...

Chosen dr jan nolta- stem cell researcher head of uc davis

Chosen Dr. Jan Nolta- Stem Cell Researcher Head of UC Davis Stem Cell Program Director Topic Background: early Stem cells have the ability to develop into many different types of cells. Stem Cell Research is not without ...

  • 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