Science NetLinks: Mitosis

Lesson Plan Navigator
and


	5C Cells #2 Cells repeatedly divide to make more cells for growth and repair....

Send us feedback

Printer icon Print this lesson

Mitosis

Purpose

To develop an understanding of mitosis.

Context

Students have been taught at an early age that the cell is the building block of life, and have most likely used a simple microscope to view cells in elementary school. They have been introduced to the idea that organisms depend on cell division to pass the genetic information from one cell to the next, but how this is accomplished is still a mystery. They are now ready to understand the concept that one cell is capable of making an exact copy of itself.

This lesson will introduce students to the step-by-step phases of mitosis in an effort to imprint on the young mind the idea that each cell is highly organized. Prior to this lesson, students should have discussed both plant and animal cell structures. If they haven't, focus students solely on animal cells throughout the lesson.

Planning Ahead

In this lesson, students will make physical representations of mitosis. Read the activity ahead of time and choose appropriate materials for your class.

Possible materials:

Poster board
Glue
Scissors
Yarn (any color)
Several small beads
Lifesavers or other round candy
Construction paper
Macaroni
Spools of thread
Markers, crayons, or colored pencils

Students will also develop and perform a skit about the phases of mitosis. The props needed for this activity will depend on your students' ideas as they create the skit.

Motivation

Help students focus on cell division by asking questions such as:

Has your body changed in the past six months?
How did you recognize this change?
Are you taller? Did your hair grow? Did you clip your toenails?
Has anyone broken a bone recently?
How does your body repair itself?

Say to students: We are going to investigate the process by which cells make exact copies of themselves. Bone cells repair bone cells, hair cells cause your hair to grow, and new fingernails grow to replace broken ones. Practically every cell in your body is capable of making a copy of itself through the process of mitosis. Plant cells replicate by mitosis as well. There is another process by which living things make an entirely new organism, but that won't be discussed in this lesson. We will focus on plant and animal cells making exact copies of themselves.

Development

Introduction to the Phases of Mitosis
Ask students to scroll through the set of five pictures on the Stages of Mitosis page, which is part of the University of North Carolina at Charlotte Biology website, as you briefly explain each stage. (Using a presentation station simplifies this task.) Ask students to identify the cell parts they recognize when appropriate.

Scroll through the pictures again, instructing the students to draw and take notes on each of the five stages. Next to each picture, students should write the name of the stage it depicts.

To learn more as well as to check for understanding, have students view the Mitosis Animation on the University of Arizona's The Biology Project website (the animation is at the bottom of the page.) You will need the QuickTime plug-in to view the animation.

Let the animation run, then click through each picture, pausing for discussion. Ask students to describe what is happening in each image.

Creating a Physical Representation of Mitosis
In this part of the lesson, students will create physical representations of mitosis on poster board, using a variety of the materials listed in the Planning Ahead section (e.g., yarn to represent chromosomes, lifesavers to represent centromeres).

Students should divide the poster board into five sections (one for each phase of mitosis) and use what they have learned to depict each phase. Students may work independently or in pairs to illustrate mitosis of a plant or animal cell, with the shape reflecting the type; plant cells should be rectangular, and animal cells should be more circular.

You may give specific instructions to the students, or set them free and let their creative juices flow!

Possible instructions include:

Label the first box Interphase. Draw a circle or rectangle to represent the cell (plant or animal cell) and a small circle in the center to represent a nucleus. The chromosomes cannot be seen yet and the picture should reflect this. Label the cell membrane, the nuclear membrane and the chromatin. If it is a plant cell, also draw and label a cell wall.
Label the second box Prophase. Draw a cell and use small pieces of yarn to represent the chromosomes. Use four chromosome pairs. Glue the yarn in place, keeping the pairs together. Use small circles of construction paper, small beads, or lifesavers to represent the centromeres, which are attached to the chromosome pairs. The nucleus has disappeared during this phase and the picture should reflect this idea. You may use small rectangles cut from construction paper or pieces of macaroni to represent the centrioles. Label the chromosomes, centromeres, centrioles, and the cell membrane.
Label the third box Metaphase. Draw the cell and use four double pieces of yarn to represent the double-stranded chromosomes as in prophase. These chromosomes are lined up along the middle of the cell and glued in place. Glue the two objects used to represent the centrioles at opposite ends of the cell. You should also use the glue to attach pieces of thread or string to the yarn chromosomes to represent the spindle fibers. Label the cell membrane, chromosomes, spindle fibers, and the centrioles in this picture, as they are the key organelles in this phase.
Label the fourth box Anaphase. This cell model should reflect the chromosomes separating and moving to opposite ends of the cell. The spindle fibers are shorter and the four double chromosomes are now being pulled away from each other to form a new cell, identical to the first. Glue all pieces into place and label appropriate parts. (The teacher may direct the labeling in this phase.)
Label the fifth box Telophase. In the final step of mitosis, the spindle fibers have disappeared along with the centrioles. Draw the cell membrane. Also draw a nuclear membrane and lightly draw lines to represent the chromosomes (they are barely visible in this phase). If the cell is a plant cell, also draw a line to represent the cell wall, which is visible again at this stage.

After all the posters have dried, display them around the class in a "Mitosis Gallery." Ask students to help with the display and divide the posters into two groups based on the cell type.

To check for understanding, have students draw a flow chart depicting a cell going through four rounds of mitosis (rather than just one, as in their posters). Students should realize that four rounds of mitosis would lead to 16 cells.

Mitosis Skit
Have students write and perform a skit to show the process of mitosis, using the loose guidelines that follow. These guidelines are intended to help get you started, as well as provide room for the development of a skit that suits your class size, available supplies, and students' creativity.

Tell students that they need to write a "scene" representing each phase of mitosis. Have them refer to the posters they created to determine the essential "characters," as well as what the characters should be doing in each scene. In addition, have students create a narrator(s) role, which will explain the processes as they are happening in the skit.

Following is a sample scene, representing Metaphase:

When the narrator calls out "Metaphase," the chromosomes meet in the middle of the imaginary cell. The students playing centrioles walk into the center of the cell and had the students playing chromosomes a piece of yarn. This represents the spindle fibers attaching to the chromosomes. While holding the other end of each string, the students playing centrioles walk to opposite ends of the imaginary cell to prepare for anaphase.

Following are ideas for props to be used throughout the skit:

A circle of students could hold plastic wrap to represent the cell membrane.
A small group of students could hold bright colored construction paper to represent the nuclear membrane.
Students could hold oval-shaped construction paper to represent chromosomes; they could use two pieces, one behind the other, which can be separated in prophase when chromosomes duplicate and begin to form an "X".
Yarn can be used to represent spindle fibers.

Again, structure this activity to meet the needs of your students. It can be as simple or elaborate as you'd like, but should allow students the opportunity to refine and demonstrate their understanding of mitosis.

Assessment

Ask students to respond to the following in their science journals:

Pretend you are a theater critic and your job is to write a review of the Mitosis Skit for the school newspaper. Write a brief review that includes at least the following:

How the skit represented the process of mitosis;
a review of the players of mitosis (e.g., cell membranes, chromosomes); and
thoughts on how this skit could be improved to better represent mitosis (focusing on the science of mitosis).

Extensions
Students can find Stages of Mitosis slides of animal and plant cells at the University of North Carolina at Charlotte Biology website.

Slides of mitosis in onion root tip cells can be found on the Molecular Expressions website. This could be used after students have looked at onion root tip cells under a microscope.

The Molecular Biology Notebook could be used to extend ideas in this lesson.

Created :10/20/2001