Jane filled one transparent bottle and one brown bottle of the same capacity with pond water. she kept the first bottle in sunlight and the second in dark. after one hour she calculated the amount of oxygen present in both the bottles. what will be her observation? in the transparent bottle, the algae and small plants present in the pond water utilize oxygen for photosynthesis. in the brown bottle, due to darkness they cannot utilize oxygen dissolved in the water. therefore, oxygen in the transparent bottle is lesser than that in the brown bottle. in both the bottles the algae and small plants present in the pond water carry out photosynthesis. therefore, the amount of oxygen in both the bottles remains the same. in the transparent bottle, the algae and small plants present in the pond water release oxygen during photosynthesis, while in the dark bottle, photosynthesis doesn’t occur due to darkness. therefore, oxygen in the transparent bottle is more than that in the dark bottle.

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.