MitosisInquiring Minds Want to KnowSUNY EmpireTami Gilbeaux

Bell Ringer & Lab Goals

Review of mitosis stages via video http://www.teachersdomain.org/resource/tdc02.sci.life.stru.dnadivide/

Complete the worksheet—Call on individual students for the answers

Discuss characteristics of mitosis stages in preparation of the lab

The goal of the lab is to observe the different stages of cellular growth including the entire process of mitosis. You will work with your lab partner seated next to you to locate and view the onion cell root tips under the microscope.

Mitosis Lab InstructionQuiz the students about lab techniques and safety using this

worksheet.

Ross, how do we act when we conduct experiments?◦ We must conduct ourselves in a responsible manner and follow all

instructions carefully. Megan, what else is important to keep everyone safe?

◦ We must never work alone or without the teacher and we have to keep the aisles clear. Oh, yes, we must keep our hands away from our face, eyes and mouth while conducting the experiment.

Dillon, how do we handle the slides?◦ We hold the slides by the edges and not put our fingers directly on

the slides. If it is chipped, we call you, Ms. Gee, immediately. Leslie, can you tell us about the microscope?

◦ Yes, we have to handle it properly like we already know how to do. And finally, Megan, what do we do when we finish the lab?

◦ We wash our hands.

Essential Question & Student Hypotheses

Do all phases of the cell cycle

require the same amount of time?

Dillon says, “ If I count the onion cells,

then I predict to see more cells in Interphase

than in Telophase.”

Megan says, “ If I count the onion cells,

then I will see all phases of

mitosis.”

Bradley says, “If I see the onion cells,

then I will see more of

Prophase.”

Ms. Gee’s Inquiring Minds…

•I see the cells in Prophase.

“Dillon, what do you see in this

quadrant?”

•I see the spindles forming. This is the beginning process for the new cell to get all of the chromosomes needed.

“Megan, How does each cell get a complete

set of chromosomes? Do you see this phase in your

samples?”

Compiling & Documenting Data

Now it is time to record your data and prepare for the presentation of your findings.

We will use the laptop and an

excel file to chart your data. Each student has been assigned a time to use the laptop.

For those with access to a laptop at home, please

email the chart to me and you can

add it to the overall

spreadsheet in class.

In additional to your charting, let’s

answer the following

questions to supplement your

lab findings:

Student Responses to Lab Data Questions

Sydney, what information did you learn when charting your data?

• We all had different data, but there were more cells in iIterphase than the other phases.

Bradley, what phase of the cell cycle is the longest? Why?

• Hey, my hypothesis is right!! It seems that the cells in Interphase were the longest. This is where the cell grows and replicates the DNA and centrioles.

Megan, What would happen if a cell did not make a copy of the DNA before mitosis?

• If a cell did not make a copy of the DNA before mitosis, there would be one cell with no DNA—does that mean it is not a cell?

Dillon, what happens if mitosis is not followed by cytokinesis?

• Without cytokinesis, the cytoplasm would not split into two distinct cells. There would be only one cell with two identical nuclei.

What Did You Learn Today?(Your parents will ask)

Class, what did you find interesting about the

observation of the onion cells?

Growth continues through the process of mitosis. There are

different phases that have to occur for cells to multiply

—Interphase, Prophase,

Metaphase, Anaphase,

Telophase and Cytokinesis.

Dillon, Megan and Bradley, tell me how your results compared

to your hypothesis?

Dillon—I found out that my hypothesis is correct! I saw more cells in Interphase, the

longest stage of mitosis.

Megan—I did see all the phases of the cell cycle and mitosis. There were not as

many in Telophase or Cytokenisis.

Bradley—My data showed that I saw more

in Interphase than in Prophase, as I predicted.