Name_________________________
The Cell Cycle Lab
Online Onion Root Cells
PRE-LAB QUESTIONS:
1. What is a chromosome?
2. What is a sister chromatid?
3. If I have 50 cells total and 20 of those cells are blue, how do I find the percent of blue cells? Write the
equation you used to solve the problem and then the answer.
To complete the following online lab, go to www.biology.arizona.edu
Click on CELL BIOLOGY and then Click on ONLINE ONION ROOT TIPS
1. Read through the page and answer the following questions in COMPLETE SENTENCES.
a. What type of cells will you be observing?
b. Why are root tip cells good for studying mitosis?
2. Click NEXT and answer the following questions.
a. What are the 6 major phases of the cell cycle in order?
b. Write the name of the phase in which we can first see chromosomes. ______________________
c. Write the name of the phase in which the spindles first appear. ___________________
d. Write the name of the phase in which the chromosomes align in the middle of the cell.
___________________
Name_________________________
e. Write the name of the phase in which 2 new nuclear envelopes form around the chromosomes.
_________________________
f. Write the name of the phase in which the paired chromosomes separate and move to opposite
sides of the cell ____________________________
g. Write the name of the phase in which the nuclear envelope disappears ___________________
3. Click on NEXT and read the assignment at the top of the webpage. Use the date table below to record
your final data once you finish the assignment. Use a calculator to figure out the percent of cells at each
phase.
INTERPHASE PROPHASE
METAPHASE ANAPHASE
TELOPHASE
TOTAL
Number of
Cells
36
Percent of
Cells
100%
4. Create a bar graph below to represent the number of cells at each phase of the cell cycle.
Name_________________________
5. CONCLUSION QUESTIONS: Answer the questions in COMPLETE SENTENCES
a. Based on the data you collected, in what phase does a cell spend most of its time?
In what phase does a dividing cell spend the least amount of time?
b. Why do you think the sister chromatids line up down the center of the cell?
c. What are the two major purposes of the cell cycle? (Why do cells need to make copies?)
6. Extension – yes, you have to do it!
Go to www.classzone.com.
Choose the High School Science Book for Ohio.
Choose the Biology Book (lizard on front).
Click Animated Biology.
Choose Unit 2: Cells.
Choose Chapter 5: Mitosis Stage Matching.
Look at the pictures of cells and drag the picture into the phase where the cell belongs.
Don’t worry, it will tell you if you need to try again!
When you’ve completed this, print out the page (you should be able to right click and choose print) and hand it
in with this lab, with your name on it.