Mitosis NOTES

1

February 11, 2015

MitosisCell Division

• is the part of the cell cycle when body cell divides into two identical "daughter" cells

• occurs after DNA replicates itself

Mitosis

Mitosis NOTES

2

February 11, 2015

• This is the number of chromosomes in an eukaryotic body cell • All species have a specific chromosome number

An individual has to sets of chromosomes so all species chromosome number are 2n

• In humans there are 46 chromosomes (2n=46) or 23 pair (n)

• one pair is passed down from one parent and the other pair is passed down from the other parent

Chromosome Number

Body Cells

Gametes

• This includes all of the cells in our body (tissues like skin and bone) except gametes• Each cell has a paired set of chromosomes • Written as 2n• diploid

• This includes only egg and sperm cells• 1 set of chromosomes• Written as n• haploid

Mitosis NOTES

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February 11, 2015

Chromosomes Number Before and

After Mitosis

BeforeParent Cell = 2n

After Daughter cell = 2n

They are identical

• 2n -----> 2n + 2n parent cell forms 2 identical daughter cells

• Two new daughter cells are produced from an original parent body cell, each with the correct “2n” number•• Daughter cells are genetically identical to the parent cell and to each other

Result of Mitosis

Mitosis NOTES

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February 11, 2015

1. The correct chromosome number for the species is preserved

2. Allows for growth by adding cells

3. Allows for repair by replacing damaged cells with new cells

Benefit of Mitosis

• Interphase: (before Mitosis begins)-cell growth, DNA replication, preparation for mitosis

• Prophase: chromatids pair up to form chromosomes/nucleus begins to disappear

• Metaphase: centrioles move to opposite poles/chromosomes line up in the middle/fibers attach to chromatids

Stages of Mitosis

Mitosis NOTES

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February 11, 2015

• Anaphase: chromosomes are pulled apart by fibers into separate chromatids

• Telophase: 2 new cells begin to form/ nuclear membrane returns

Cytokenesis-cytoplasm separates, causing 2 new, identical cells to form

Stages of Mitosis

Attachments

Mitosis.mov

SMART Notebook

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