Here is graph of describing what happened to a culture when it was exposed to a
ID: 215762 • Letter: H
Question
Here is graph of describing what happened to a culture when it was exposed to a temperature higher than it's maximum temperature LOOE 1. The following tow questions are about using heat to kill microorganisms. OOEG7 What is the decimal reduction time for this organism? (1 point) a. CFU/ml Time in seconds b. You repeat DRT experiment with a Gram-positive rod and this is the result. Your water bath maintained a constant temperature; your dilution and plating technique is perfect. All the colony morphologies match that ove your original culture. What would cause this result? (1 point) CFU/ml 10 100 200400 00 00 Time in Seconds 2. Lacl and LacZ are proteins encoded by genes, and there can be mutated forms of them. The place where Lacl binds, lacO, is also a DNA element, and is subject to mutation. In the table below, I've listed a number of potential mutations. I want you to tell me after growing each mutant in a minimal medium with equal parts glucose and lactose, both sugars at 0.2% do you think you'd see blue in a -galactosidase assa ? (2 points Mutation: or No Color Change? A Lacl mutated so that it no longer recognizes laco A Lacl that no longer binds lactose A LacZ that no longer cleaves lactose A lac0 mutated so Lacl no longer recognizes it. A one base frame shift mutation after the first 9 bases of laclExplanation / Answer
1. 200 S
2. Spore formation
3. A. Blue - LacI mutated so it not repress the lac operon. So constitutively express the operon.
B. No color change - LacI binds to opertor it not release from the operator due to binding site gets mutated.
C. No color change - Cleaved lactose activates the lacZ
D. Blue - lacO muataed so nno binding of lacI. So always express
E. Blue - LacI frameshift muatation leads to non functional repressor.