Personal Genome Project Study Guide
    Welcome About the PGP About the Study Guide FAQ Contact Credits
Part I: Genetic Material

Part II: Gene Transmission

Part III: Gene Expression

Part IV: Genetic Regulation

Part V: Genetics and Society

Part VI: Project Literacy

 

 

 

 

 

  Part II: Gene Transmission
Lesson 5: Meiosis
Goals123456 
Lesson 5 Practice Test

To grow tissue and renew cells, existing cells divide by mitosis.  The steps of mitosis are:

  1. 1.Growth in cell size
  2. DNA replication.  The chromosomes duplicate themselves so that instead of two copies of every gene per cell (the normal diploid condition), there are 4 copies of every gene.
  3. The cell's nucleus dissolves, and the chromosomes distribute themselves into two identical diploid sets at opposite sides of the cell.
  4. Two new nuclei form around the sets of chromosomes.
  5. The cell splits into two cells, each with its own nucleus and each with a diploid set of chromosomes.

Mitosis produces genetically identical cells.  Cells in the human body divide by mitosis.  The only exception occurs during the production of sperm and egg cells.  These cells are produced by meiosis.