Lab 2 Exam Questions And Correct Answers | Verified |latest Update

Which temperature seems to be closest to the optimum temperature for pigment formation in Serratia marcescens? {Ans: Although S. marcescens will grow at 38 degrees C, it will not produce the red pigment at that temperature. It will only produce the red pigment at lower temperatures..}Why was half of each plate covered with an index card? {Ans: It serves as a control to block UV light.}There is definitely survival of some microorganisms even after alcohol treatment. Without staining or microscopic scrutiny, predict what types of microbes are growing on the medium where you made the right thumb impression after treatment. {Ans: Gram-positive because they have a thicker peptidoglycan layer and no LPS to dissolve. Also endospore formers and other difficult to kill microorganisms.}Describe the damaging effects of UV radiation on living cells. {Ans: It is mutagenic by causing pyrimidine dimers that change the structure of the DNA in places so replication as well as transcription will be problematic.}What types of damage to human tissues can result from prolonged exposures to UV radiation? B. What protective measures can be taken to limit these types of damage, both during the experiment and in everyday life? {Ans: DNA