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Mitosis Internet Lesson. Un'attività per il CLIL di Biologia in lingua inglese

red - Di seguito viene proposta un'attività sulla mitosi, utile per le classi in cui sono attivi dei percorsi CLIL di Biologia in lingua inglese.

Mitosis - Internet Lesson

To study mitosis, biologists often look at particular cells. Remember, that mitosis occurs only in areas of growth, so finding a good spot to study it can be challenging. Two specimens are commonly used by biologists to study mitosis: the blastula of a whitefish and the root tip of an onion.

The whitefish embryo is a good place to look at mitosis because these cells are rapidly dividing as the fish embryo is growing. The onion root is also a good place because this is the area where the plant is growing. Remember that when cells divide, each new cell needs an exact copy of the DNA in the parent cell. This is why mitosis is only visible in cells that are dividing, like the whitefish embryo and the onion root tip.

Mitosis can take several hours to complete. Scientists will make slides of cells that should be undergoing mitosis in order to find a particular cell in any of the stages - prophase, metaphase, anaphase, and telophase. Remember that most cells you see will be in interphase, that's the cells "resting" state. Your task is to look at photographs of actual slides and identify the stages of mitosis. Answer the questions on each page in your lab notebook or print this first page and answer direction on it.

Pre-Lab:

Review the stages of mitosis at: http://www.cellsalive.com/mitosis.htm

1. What are the four stages of mitosis?

2. How long does it take for mitosis to complete? Why will most of the cells you view be in interphase?

Internet Lab:

In this internet lesson, you will review the steps of mitosis 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 at http://www.cellsalive.com/

On the left side of the screen is a navigation bar, click on the link to “MITOSIS” Read the text on this page and view the animation, you can slow down the video by clicking step by step through the phases.

1. Which stage does the following occur:

  • Chromatin condenses into chromosomes ________________
  • Chromosomes align in center of cell ________________
  • Longest part of the cell cycle ________________
  • Nuclear envelope breaks down ________________
  • Cell is cleaved into two new daughter cells ________________
  • Daughter chromosomes arrive at the poles ________________
  • Chromatids are pulled apart ________________

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?

  • How many are in each daughter cell at the end of mitosis? __________________
  • The little green T shaped things on the cell are: ____________________________
  • What happens to the centrioles during mitosis? _____________________________

Another Mitosis Animation

Go to http://www.johnkyrk.com/mitosis.html . Draw a cell in each of the following phases.

Prophase

 

Metaphase

 

Telophase

Onion Root Tip

Online Activity at http://www.biology.arizona.edu/cell_bio/activities/cell_cycle/cell_cycle.html

Read the introduction, and then click the “next” button.

You will have 36 cells to classify. When you’re finished, record your data in the chart below. Round to whole numbers.

 

Interphase

Prophase

Metaphase

Anaphase

Telophase

Total

Number of Cells

 

 

 

 

 

 

Percent of Cells (calculate: number of cells divided by total cells x 100)

 

 

 

 

 

 

Mitosis in Whitefish & Onion Roots

Click on the Whitefish embryo and the onion root tip:

http://www.biologycorner.com/projects/mitosis/whitefish_embryo.html.

http://www.biologycorner.com/projects/mitosis/onion_root.html

For each organism, identify the stage of mitosis.

 

View 1

View 2

View 3

View 4

View 5

Whitefish

 

 

 

 

 

Onion

 

 

 

 

 

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