Question: In a cotransformation experiment (see solved problem S4), DNA was isolated from a donor strain that was proA+ and srrC+ and sensitive to tetracycline. (The

In a cotransformation experiment (see solved problem S4), DNA was isolated from a donor strain that was proA+ and srrC+ and sensitive to tetracycline. (The proA and strC genes confer the ability to synthesize proline and confer streptomycin resistance, respectively.) A recipient strain is proA- and srrC- and is resistant to tetracycline. After transformation, the bacteria were first streaked on a medium containing proline, streptomycin, and tetracycline. Colonies were then restreaked on a medium containing streptomycin and tetracycline. (Each type of medium had carbon and nitrogen sources for growth.) The following results were obtained:
70 colonies grew on the medium containing proline, streptomycin, and tetracycline, but only 2 of these 70 colonies grew when restreaked on the medium containing strepto'mycin and tetracycline but lacking proline.
A. If we assume the average size of the DNA fragments is 2 minutes, how far apart are these two genes?
B. What would you expect the cotransformation frequency to be if the average size of the DNA fragments was 4 minutes and the two genes are 1.4 minutes apart?

Step by Step Solution

3.40 Rating (153 Votes )

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock

A We first need to calculate the cotransformation frequency which equ... View full answer

blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Document Format (1 attachment)

Word file Icon

894-M-S-B-G (401).docx

120 KBs Word File

Students Have Also Explored These Related Biology Questions!