Laboratory Investigation:

Mitosis

 

Cell Division

Now the cell will make an extra copy of each chromosome.  This will allow the cell to divide without losing any information.  A plant or an animal is made of millions of cells.  Each time a copy is made of a cell so that the organism can grow, none of the genetic information is lost.

Below is an animation showing copies being made of  the genetic information:

For a short time, the cell will contain more genetic information than it normally does.  

  • How much more genetic material is in the cell now compared to its usual quantity? 

  • Has the number of chromosomes changed?

  • Explain: 

Now the cell is ready to divide.  The set of extra copies of the 8 chromosomes moves to the new cell. The animation below shows this separation:

Here are the two daughter cells which have formed:

  • How many chromosomes are in each cell?

  • From a genetic point of view, are these two cells identical? 

  • Are the two daughter cells identical to the original cell before it divided?  

  • If the original cell was a skin cell from an adult, could one or both of the daughter cells be something different - a nerve cell, for example?

 

Click on the next page to see another form of cell division:  Meiosis.