Reduce, reuse, recycle

Before the can be observed by using a transmission electron microscope, cells are sliced into very thin sections. what disadvantage does this procedure present in the study of cellular parts

Vinegar has a ph of 3, and household ammonia has a ph of 11. is the concentration of h+ greatest in the vinegar or ammonia?

In general, characteristics that an organism survive and reproduce become more common in a population over time. what mechanism of evolution cause this change?