A hand sanitizer was advertised to be more effective at killing bacteria than any antibacterial soap. Students were split evenly into 4 groups to test this claim. Groups 1-3 washed their hands using the assigned hand sanitizer or soap (see table) and warm water for two minutes, and then dried their hands with a paper towel. Group 4 rubbed their hands vigorously for 2 minutes in warm water, without any soap or sanitizer, and then dried their hands with a paper towel. After washing, each student’s hands were swabbed and the swab was applied to a culture plate and incubated. Finally, the bacterial cultures were counted. What are the independent and dependent variables in this experiment? What is the control group? List 3 constants. *

How does upwelling affect coastal fisheries? upwelling damages nutrient supplies at coastal fisheries as the warm, nutrient-rich surface water is replaced by nutrient-poor, cold water. upwelling damages nutrient supplies at coastal fisheries as the cold, nutrient-rich surface water is replaced by nutrient-poor, warm water. upwelling improves the nutrient supply at coastal fisheries as the warm, nutrient-rich surface water replaces the nutrient-poor, cold water. upwelling improves the nutrient supply at coastal fisheries as cold, nutrient-rich water replaces the warm, nutrient-poor surface water.

Astudent from one of the research labs is having trouble preparing a slide for examination and photographing. the bacterial slide that he has brought to you was prepared using a commercially purchased stain. he has asked for your in determining what he is doing wrong so that he can change the lab protocols and continue on with his project. after examining the slide under oil immersion, you determine that no bacteria are present even though the student is able to show you the culture he used to make that slide that has visible growth in the liquid medium. which of the following statements does not explain the fact that there are no bacteria present on the student’s slide? by not allowing a glass slide to completely air dry before heat fixation, the flame will cause the surrounding water to boil and this will damage the bacterial cell. overheating during the fixation step boiled the water within the bacterial cells and resulted in the cells bursting. insufficient heating of the slide did not drive out the thin layer of water and this resulted in minimal bonding between the bacteria and the glass slide. rinsing with alcohol during the washing step stripped the bacteria off the glass slide. rinsing with alcohol during the washing step stripped the bacteria off the glass slide.

Why are recessive alleles not removed from populations over time? a.individuals can pass recessive alleles on to offspring b.recessive alleles are removed with enough time c.recessive alleles will always reappear after being removed