thank u 4 the help. But check this part out. I did an experiment and when the oil was added to the yeast the oil began to rise, and the yeast rose afterwards. During the occasional rising of the yeast, bubble appeared in the lime juice. As the oil settled at the bottom of the test tube, and the yeast settled at the top.
Can u say why all of this occurred please?
I can't really understand what you mean here. The oil should NEVER settle at the bottom of the test tube, as it floats on water! The bubbles aren't a surprise, because anaerobic respiration in yeast (unlike in animals) produces carbon dioxide.