The document provides instructions for students to count cells in different stages of the cell cycle (interphase, prophase, metaphase, anaphase, and telophase) by examining an onion root tip specimen under a microscope. Students are asked to tally the number of cells in each stage and calculate the percentage of total cells in each stage to input into an Excel spreadsheet to create a pie chart. The homework task is to analyze which stage had the most cells based on what occurs in each phase of the cell cycle.

1. Representation Description Diagram

2. Onion root tip – cell count
Task #1
Now that you are able to identify cells in different stages of the cell cycle, now it
is time to understand how long a cell will tend to be at each of these stages.
The task is to count how many cells in your root tip specimen were ‘frozen in
time’ in different stages of division when this slide was made.
Tip 1 –For cells that do not appear to be in a stage of division, if there is no
clearly defined nucleus, disregard the cell. If the nuclear envelope is
clearly defined then this can be counted as a cell in interphase.
Tip 2 - The most efficient way to conduct this part of the experiment is if one
member of your group scans the sample whilst the other member keeps a
tally of the cells cited.
Stage of Interphase Prophase Metaphase Anaphase Telophase Total
Mitosis
Cell count
Percentage 100%
Task #2
This is your homework task
Calculate the percentage of the total number of cells for each stage of the cell
cycle and then put this information in to an Excel spreadsheet. Use this
spreadsheet to create a pie chart, and bring this to next class for analysis.
Discussion
In which phase of the cycle did you find most cells? Based on your knowledge of
what the cell is doing at each stage can you explain your findings?