Ap Biology Lab Report

1. This experiment was performed using cells from 3 different species, Vicia faba (broad bean), Allium cepa (onion), and Coregonus clupeiformis (whitefish), which obviously have variability between them. Onions are bulb plants, meaning they have a ball of stored nutrients underneath the soil out of which the roots protrude, where the broad bean does not have a bulb, having most of its mass above the soil. The whitefish is of course an animal, entirely different from the plants, including in how the cell cycle is performed. A cleavage furrow forms instead of a cell plate to perform cytokinesis, and centrosomes are present in its mitotic cycle, unlike in plants. It should also be said, pertaining to this experiment, that whitefish travel to spawning grounds to reproduce, and that there is no parental care, which could have an effect on the rate of cell division in embryonic and larval whitefish. The data my group collected is somewhat similar to the average data, though it has some significant differences. The

Based on the observations collected over the three species, interphase is by far the longest phase, and metaphase, anaphase, and telophase are similar in length, with telophase being slightly shorter. In the broad bean, almost all of the cells were in interphase, for reasons stated in the previous question. In the onion root, about 3/4 of the cells were in interphase, with most of the rest in prophase, and a few in metaphase, anaphase, and telophase. The whitefish had about 70% in interphase, with most of the rest in prophase (15%) , and more in metaphase than in the previous species (6%). The whitefish could have had more cells in metaphase because being animal cells, they require the centrosomes to align at opposite poles, which may cause it to take longer. As well, slightly longer relative times were observed in the plant telophase, which may have occurred due to the forming of the cell plate in plant cells, which could cause this phase to take