MitosisMitosisUnit 4-2 Notes

Mr. Hefti – Pulaski Biology

1. Definition1. Definition

• Cell division producing 2 identical cells each having a complete set of homologous chromosomes (2N).– 2N means diploid– 1N means haploid

• Any new cells called daughter cells

• Mitosis for growth and repair!

2. What is the diploid number in 2. What is the diploid number in humanshumans??

• Body cells have 23 pairs of chromosomes (23+23 = 46)

–Diploid

• Gametes (egg and sperm cells) have 23

–Haploid

3. Which types of cells are made 3. Which types of cells are made this way?this way?• Muscle cells• Skin cells• Nerve cells• Bone cells• Many others…

• Think of all of the different types of cells in your toes!

• Every type of cell except gametes!

4. How do the resulting cells 4. How do the resulting cells compare to each other?compare to each other?

• Genetically identical to each other and to the parent cell!

• Importance - preserves a cell’s structure and function

5. What is the mathematical 5. What is the mathematical equation for mitosis?equation for mitosis?• 2N ￫ 2N + 2N• Translation: “A diploid cell divides

and makes 2 new diploid cells.”

6. What are the stages of 6. What are the stages of mitosis?mitosis?• Interphase: chromosomes replicate

• Prophase: chromosomes become visible and the nuclear envelope dissolves

• Metaphase: chromosomes line up in the middle

• Anaphase: chromosomes pull to opposite ends

• Telophase: cells separate

7. What happens if the steps of 7. What happens if the steps of mitosis don’t go in order?mitosis don’t go in order?

• Most likely result… the cells do not develop properly and die

• Sometimes the new cells will survive with a mutation

• _________ phase: chromosomes replicate• _________ phase: chromosomes become visible and the nuclear envelope dissolves• _________ phase: chromosomes line up in the middle• _________ phase: chromosomes pull to opposite ends• _________ phase: cells separate

• _________ phase: chromosomes replicate• _________ phase: chromosomes become visible and the nuclear envelope dissolves• _________ phase: chromosomes line up in the middle• _________ phase: chromosomes pull to opposite ends• _________ phase: cells separate

• _________ phase: chromosomes replicate• _________ phase: chromosomes become visible and the nuclear envelope dissolves• _________ phase: chromosomes line up in the middle• _________ phase: chromosomes pull to opposite ends• _________ phase: cells separate

• _________ phase: chromosomes replicate• _________ phase: chromosomes become visible and the nuclear envelope dissolves• _________ phase: chromosomes line up in the middle• _________ phase: chromosomes pull to opposite ends• _________ phase: cells separate