Name, Date, Hr/Pr _____________________________KEY
KEY______________________________________________
KEY
The Cell Cycle -- Internet Lesson & Webquest
In this internet lesson, you will review the steps of mitosis and meiosis and view video simulations of cell
division. You will also view an onion root tip and calculate the percentage of cells at each of the stages of
cell division.
Mitosis Tutorial
Go to: http://www.cellsalive.com/mitosis.htm
Read the text on the page and view the animation. You can slow down the video by clicking step-by-step
through the phases. Then, complete the table below – IN WHICH STAGE DOES EACH OCCUR?
1. Chromatin condenses into chromosomes
___
_prophase_
prophase___
2. Chromosomes align in center of cell.
__metaphase
metaphase__
metaphase
3. Longest part of the cell cycle.
__interphase
interphase__
interphase
4. Nuclear envelope breaks down.
__prophase
prophase__
prophase
5. Cell is cleaved into two new daughter cells.
__telophase/cytokinesis
telophase/cytokinesis__
telophase/cytokinesis
6. Daughter chromosomes arrive at the poles.
__telophase
telophase__
telophase
Watch the video carefully.
The colored chromosomes represent chromatids. There are two of each color because one is an exact
duplicate of the other.
7. How many chromosomes are visible at the beginning of mitosis? _4
4 (interphase); 0 (prophase)_
(prophase)
[either ok – mitosis doesn’t really start until prophase, but this question was posed re: interphase]
8. How many are in each daughter cell at the end of mitosis? _4
4_
9. The little green T shaped things on the cell are: __centrioles
centrioles__
centrioles
10. What happens to the centrioles during mitosis? _move
move to ends of cell; pull chromosomes
chromosomes_
omosomes
_ with spindle fibers_
fibers
Identify the stages of these cells [write stage below the picture]:
prophase_______________
11. ____________
telokphase/ cytokinesis__
12. __
metaphase_____________
13. _____________
Mitosis Animation
Go to: www.sci.sdsu.edu/multimedia/mitosis/
*this takes a while to load, be patient.
ANSWER THESE QUESTIONS BASED ON WHAT YOU FIND ON THE SITE..
SITE.. IF YOU CANNOT FINISH DURING
THE HOUR, USE OTHER REFERENCES OR ACCESS THE SITE AT HOME OR THE LIBRARY.
LIBRARY.
14. What is a eukaryote? __cells
cells with a nuclear membrane surrounding their DNA__
DNA
15. What is a non-reproductive cell? __neither
neither sperm nor ovum [egg]__
[egg]
Click on “What is Mitosis” after the page has loaded to view the animation and complete the following table.
Phase
What happens during this phase?
16.Interphase
DNA replicates, centrioles divide, proteins are produced, organelles double
17.Prophase
nucleolus fades, chromatin condenses into chromosomes, microtubules disassemble to
form the spindle
spindle
18.Prometaphase
nuclear envelope disappears/breaks down, spindle fibers eongate and attach to
[aka latekinetochores or other fibers at other sides of cell
prophase]
19.Metaphase
chromosomes align in the center along the equator
20.Anaphase
spindle fibers shorten, kinetochores separate, chromatids start moving to poles
21.Telophase
chromatids arrive at poles, spindle fibers disappear
Another Mitosis Animation
Go to www.johnkyrk.com/mitosis.html
22. Prophase
View the animation and sketch the cell in:
23. Metaphase
24. Telophase
[see site / book / notes for images] [see site / book / notes for images] [see site / book / notes for images]
Onion Root Tip - Online Activity
http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html
Read the introduction, then click the “next” button.
You will have 36 cells to classify. When you’re finished, record your data in the chart below.
Interphase
Prophase
Metaphase
Anaphase
Telophase
Total
20
10
3
2
1
36
55.6
27.8
8.3
5.6
2.7
100 %
[25-29] Number of cells
[30-34] Percent of cells
(calculate: number of cells
divided by total cells x 100 )