Q 1. The susceptibility tests included in this unit are typically used to differentiate between Gram-positive cocci. Would you predict them to be an affective differential test for Gram-negative oganisms? Why or why not? Q 2. Why is important to get a bacterial lawn rather than isolated colonies on the […]

a) In explaining their findings, the authors have ignored a major threat to the validity of their estimates of exposure. Explain and discuss this error. b)Specify the alternative study design should overcome this problem and why? c) Rate the study’s internal validity; low, medium or high. Explain this systematically in […]

If we add 100 ul of 0.5 mg/ml ConA and 100 ul of 1 M mannose to 800 ul of a dilute suspension of red blood cells in ConA buffer, what should we expect to happen? Explain why we expect to see these results. (Describe what is happening at the […]

The expected ratio of phenotypes among the progeny of a test cross is 1:1:1:1. Out of 200 total resulting progeny, 48 occur in one of the four phenotypic classes. Given this information, which of the following must also be true? 1) Since 48 is so close to the expected value, […]