Mitosis Tutorial Virtual Lab

1. Which stage does the following occur
Chromatin condenses into chromosomes
PROPHASE
Chromosomes align in center of cell.
METAPHASE
Longest part of the cell cycle.
PROPHASE OR ANAPHASE, (DEPENDING ON IF YOU ARE INCLUDING PROMETAPHASE OR NOT)
Nuclear envelope breaks down.
PROMETAPHSE
Cell is cleaved into two new daughter cells.
CYTOKINESIS
Daughter chromosomes arrive at the poles.
TELOPHASE
Watch the video carefully.

2. The colored chromosomes represent chromatids. There are two of each color because one is an exact duplicate of the other.

--How many chromosomes are visible at the beginning of mitosis?
8

-- How many are in each daughter cell at the end of mitosis?
4

--The little green T shaped things on the cell are:
Centrioles

-- What happens to the centrioles during mitosis?
The fibers (with the chromatids attached) hook on to the centrioles who then travel to opposite poles of the cell and are split into each cell when it is divided. (Question: There were four in the mother cell, and two in each daughter cell. The next generation of cells from the daughter cell will have enough centrioles, but what happens after that? Each daughter cell would only have one centriole.)

3 . Identify the stages of these cells:
Interphase: When the cell is not experiencing mitosis.
Prophase: The nucleus dissolves and chromatin condense into chromosomes.
Prometaphase: Fibers elongate to attach to either kinetochores or chromosomes.
Metaphase: Chromosomes align at the equator of a cell.
Anaphase: Daughter chromosomes are pulled to opposite poles of the cell by shortening spindle fibers.
Telophase: Daughter chromosomes arrive at the opposite ends of the cell, and the fibers disappear.
Cytokinesis: A contracting rings severs the cell in two.

Another Mitosis Animation

Go to www.johnkyrk.com/mitosis.html

View the animation and sketch the cell in:
Prophase
Chromosomes condense and become visible while the nucleus dissolves. Centrioles appear and move to opposite poles on the cell. Spindle fibers form but do not latch on yet.

Metaphase
Chromosomes line up at the equator of the cell and spindle fibers attach onto their kinetochores (where the duplicated and original chromosomes are connected).

Telophase
The nucleus reforms after spindle fibers shorten, then dissipate. Then the chromosomes disperse. Cytokinesis, while not technically considered part of mitosis, would be when the equator of the cell is stretched and begins to squeeze into two cells, then splits. This creates the two, duplicated sister cells.


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
Number of cells | 20 | 10 | 3 | 2 | 1 | 36
Percent of cells | 56% | 28% | 8% | 6% | 3% | 100% (Technically, 101%, but I rounded)


Mitosis in Whitefish & Onion Roots

http://www.biologycorner.com/flash/mitosis.html

For each organism, identify the stage of mitosis.

Whitefish
View 1: Telophase
View 2: Metaphase
View 3: Prophase
View 4: Anaphase

Onion
View 1: Prophase
View 2: Metaphase
View 3: Interphase
View 4: Telophase
View 5: Anaphase