some scientists propose that life on earth could have formed from primitive conditions, like those illustrated in the urey-miller experiment model shown above. however, more recent analysis indicates that the atmospheric components might be different than is shown above. if high rates of volcanic activity were responsible for the atmospheric conditions in the atmosphere, what modifications to the model might be necessary?
a) water vapor should be present in higher concentrations, as volcanic activity would cause more water to evaporate.
b) oxygen gas should be present in higher quantities, as photosynthesis would be occurring at a higher rate after volcanic activity.
c) ozone would be present in higher quantities, as volcanic activity would increase the combination of free oxygen atoms into ozone.
d) carbon dioxide, sulfur dioxide, and hydrogen sulfide should be present in higher concentrations than are depicted above, as they are emitted from volcanic eruptions.

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.