Onion Root Cell Virtual Lab and Lab and Meitosis

Here is a copy of the virtual lab write up and actual onion root lab. This was a pre-test to what we will need to be looking for in the actual lab. What we are looking for is the differences of Mitosis in an onion root cell. You have EARLY PROPHASE AKA INTERPHASE, PROPHASE, METAPHASE, ANAPHASE & TELEPHASE. 

Early Prophase is where the cell has a dark colored nucleus in the cell. Just like the one in the picture above.

The next is Prophase it is similar to early prophase but in prophase is where the nucleolus has disappeared and duplicated chromosomes are visible. Centrosomes begin moving apart and spindle and spindle is in process of forming.
THIS IS A PICTURE OF PROPHASE. As you can see the nucleolus has dissappeared and duplicated chromosomes are visible.

After Prophase there is Metaphase. This is where centromeres of duplicated chromosomes are aligned at the center if the cell also called metaphase plate. The kinetochore spindle fibers attached to the sister chromatids come from opposite spindle poles.

<------METAPHASE 




Anaphase follows after Metaphase and Anaphase is a really cool step in Mitosis. Anaphase is where the chromosomes move toward the spindle poles. Anaphase is the phase where the chromosomes look like fingers.

<---------- ANAPHASE

Lastly there is Telophase this is where the cell divides and the daughter cells are forming as nuclear envelopes and nucleoli reappear. Chromosomes will become indistinct chromatin. This this the step where the cell splits in half and starts the process of Mitosis all over again.

ONION ROOT TIPS AND THE CELL CYCLE


In this activity, you will calculate the lengths of the various phases of the cell cycle in an onion root tip. First you will view some slides and graphics of onion root tips provided by the Molecular Expressions Photo Gallery. Then you will complete the online activity provided by the Biology Project at the University of Arizona.

Part 1.

Use your browser to go to Molecular Expressions Photo Gallery: Mitosis

http://www.microscopy.fsu.edu/micro/gallery/mitosis/mitosis.html

Notice in the micrograph at the top of the page that there are cells in a variety of stages. View the onion slides in this section, then click on "mitosis" in the sentence "Learn the steps in mitosis ... " This will take you to a Java tutorial.  Keep in mind what you have learned here as you proceed to the second part of the activity.

Part 2.

Use your browser to go to Online Onion Root Tips at

http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/assignment.html
Begin by reading the description of the five major cell phases. You will need to keep this information in mind during the activity.

Make a copy of the data sheet that appears on the second page. You will need it to answer the questions.

Proceed through the activity, identifying the phase for each cell you are shown. Pay attention to the hints if you misidentify a cell at first.

When you have completed the activity, answer the following questions:

1. What percent of cells were in interphase?
The percent of cells that were interphase is 56%
2. What percent were in mitosis?
44% of cells were in mitosis.
3. Which phase of mitosis takes the longest?
Prophase is the phase of mitosis that takes the longest.
4. During which stage is the nucleolus visible as a dark spot?
Interphase is the stage the stage where the nucleolus that has visible dark spots.
5. How can you recognize a cell in metaphase?
You can recognize a cell in metaphase is where you can see the chromatids.
6. How might you figure out how long (in minutes and/or seconds) each phase of the cell cycle takes based on the data from these onion root cells? Explain your logic and show your calculations and results below.







7. Produce a pie chart in Create-a-Graph that shows the relative lengths of each stage of the cell cycle in these cells including interphase and each stage of mitosis. You can embed the graph here or directly in your blog.

REAL ONION ROOT LAB WRITE UP

For this actual lab write up, it is actually the same as the virtual lab EXCEPT for the fact that we had to look through a microscope at a real onion root cell. We counted all the Interphase aka Early Prophase, Prophase, Metaphase, Anaphase and Telephase.

Here is the graph of real data that we found in the onion root lab.

FOR ALL THE TWILIGHT FANS!!!!

"THE GOLDEN ONION"