Lab Manual - eScience Labs

Lab 11: Mitosis
Experiment 1: Observaon of Mitosis in a Plant Cell
Mitosis is virtually idencal in plant and animal cells, however, there is one small difference which occurs
during telophase. Plants, due to the presence of a cell wall, can not “pinch” the cytoplasm into
two daughter cells. Instead, a new cell wall must be developed which will then separate the two cells,
allowing them both to be fully covered with a cell wall.
In this experiment we will look at the different stage of mitosis in an onion cell. The large size of the
onion cell allows the different stages of mitosis to be observed with the aid of a microscope. Also,
when you are asked in the lab to specify the amount of me each stage takes during the cell cycle, remember
that mitosis only occupies 1-2 hours while interphase can take anywhere from 18-24. With
this informaon, you will be asked in the procedure below to calculate the percentage of cells in each
stage of the cell cycle.
Materials
Prepared Allium root p digital slide picture (Figure 5)
Procedure
1. The length of the cell cycle in the onion root p is about 24 hours. Predict how many hours
of the 24 hour cell cycle you think each step takes in Table 1.
2. Examine a digital slide picture (following page) of an onion root p. Count the number of
cells in each stage within a single field of view. Record this number in Table 1.
124