Mitosis Lab
Ocular lens
- 10X
Objectives
- 4X
- 10X
- 40X
Total Magnification
x 10X = 40X
x 10X = 100X
x 10X = 400X
Diaphragm – adjusts light & heat
How to use the microscope
1. Turn on – crank dial to 10
2. Adjust light with diaphragm
3. Place slide in corner & release
retractable arm….gently!!!!!!
4. Using scanning lens (4X), focus
on sample with coarse focus
5. Change objective (if needed)
6. Repeat
Mitosis Lab
Mitosis Lab
Figure 12.10
Mitosis Lab
Table 3.1
Prophase
Metaphase
Anaphase
Telophase
= 25 cells
1.
If your observations had not been restricted to the area of the root tip that
is actively dividing, how would your results have been different?
2.
Why did we choose to use the onion root tip to study mitosis?
3.
Calculate the percentage of cells in each stage. Consider that it takes (on
average) 24 hours (1440 min) for onion roots tip cells to complete the cell
cycle. Knowing this, you can calculate the amount of time spent in each
phase of the cell cycle from the percentage of cells found in each stage of
mitosis. (Recall 90% of time is spent in interphase.)
% of cells in stage (decimal) X 144 min = _____ minutes in that stage
(mitotic phase)
4.
Draw an example of each stage.