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Home Q & A Board Biology-Related Homework Help Genetics and Developmental Biology
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asjd11 asjd11
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10 years ago
(5 pnts). 3 discs were impregnated with either a control substance, chemical 1, or chemical 2 and placed on a lawn of his- Salmonella grown on medium that does not contain histidine supplement (think: would you expect this strain of Salmonella to grow on plates without histidine?).  Above are the results after incubating the plates for 2 days at 37oC.  In a few words, describe the results for the control and chemicals 1 and 2.







(5 pnts). Which chemical would you NOT recommend as a sunscreen additive and why?
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10 years ago
Quote from: asjd11 (10 years ago)
(5 pnts). 3 discs were impregnated with either a control substance, chemical 1, or chemical 2 and placed on a lawn of his- Salmonella grown on medium that does not contain histidine supplement (think: would you expect this strain of Salmonella to grow on plates without histidine?).  Above are the results after incubating the plates for 2 days at 37oC.  In a few words, describe the results for the control and chemicals 1 and 2.

If the strain of salmonella requires the amino acid histidine to grow, it will not grow is the disc's nutrients does not contain his histidine. If the stain does not require histidine, and the nutrients do not contain histidine, you will see growth because the salmonella will biosynthesize a sufficient amount of histidine to survive.



Quote from: asjd11 (10 years ago)
(5 pnts). Which chemical would you NOT recommend as a sunscreen additive and why?

I'm not sure where you are going with this question Frowning Face Is this related to the first one? Could you give me a little direction on how to answer it?

PS: Are these questions coming from a textbook?
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