Final answer:
The student was instructed not to push the cover slip sideways to prevent smearing or distortion of cells, which are being observed for the stages of mitosis. Active cell division is mainly found in the meristematic tissue of the onion root tip.
Step-by-step explanation:
The student was advised to push down hard on the cover slip but not to push it sideways to prevent the cells from getting smeared or distorted. It is crucial to maintain the integrity of the cells and their structure as they are being observed under a microscope for the process of mitosis. Smearing could make it harder to identify and count the different stages of mitosis, such as prophase, metaphase, anaphase, and telophase.
When preparing microscope slides to study mitosis, it is common to focus on areas of active cell division such as the meristematic tissue. In this area, especially just behind the root cap, one would expect to find a high number of cells actively undergoing mitosis. The prediction is that, just like the cells in the whitefish blastula, cells in the growing tip of the onion root will be rapidly dividing. As the technician moves further from the growing tip, the rate of cell division will decrease, and cells in the interphase period of the cell cycle will be more prevalent.