Download Cell Cycle

Cell Division
Cell Cycle
Cells divide to make new cells
Includes interphase and all of the stages of mitosis
Diploid Cell
Normal cells
o (e.g. skin cells, heart cells, etc)
Cell goes through mitosis
1 round of cell division
makes 2 exact copies of itself (identical)
o Daughter cells have same number of chromosomes as
parent
(e.g. 46 chromosomes in humans)
Haploid Cells
Goes through two rounds of cell division
Has only ½ of the chromosomes of the parent cell
o e.g. 23 chromosomes instead of the 46 chromosomes of a
human parent cell
End with four cells, ½ the chromosomes in each cell
Gametes (sex cells)
Chromatids
DNA & assorted proteins
Dispersed in nucleus
Not seen until the cell divides (then called chromosomes)
Chromosomes
Chromatids that have combined
Visible during division
DNA & assorted proteins
Each strand is a sister chromatid
Held together by a centromere
Gene
Part of a chromosome
Regulates the characteristics present in an individual
Mitosis (diploid cells)
Interphase
Cell is not dividing
Going through normal cell functions
Prophase
Chromosomes double and become visible
Nuclear membrane disappears
Centrioles appear
o Act as anchors as the cell divides
Spindle fibers start to form from the centrioles
o Act as fishing line
Metaphase
Chromosomes line up
o Normally in the middle of the cell
Spindle fibers attach to chromosomes
Anaphase
Chromosomes split in half
Spindle fibers contract
o Reeling in the fish
Sister chromosomes pulled to different poles of cell
Telophase
Cytokinesis
o Cytoplasm splits
Animal cells = pinches in two
Plant cells = forms a cell wall down the center of
the cell
Nuclear membrane reforms
Centrioles and spindle fibers disappear
Mitosis End Result
Two daughter cells
Identical to each other and to the original parent cell
Diploid cells, same number of chromosomes as the parent cell
Meiosis (haploid cells)
InterphaseI
Cell is not dividing
Going through normal cell functions
Prophase I
Chromosomes double and become visible
Nuclear membrane disappears
Centrioles appear
o Act as anchors as the cell divides
Spindle fibers start to form from the centrioles
o Act as fishing line
MetaphaseI
Chromosomes line up
o Normally in the middle of the cell
Spindle fibers attach to chromosomes
Anaphase I
Chromosomes split in half
Spindle fibers contract
o Reeling in the fish
Sister chromosomes pulled to different poles of cell
TelophaseI
Cytokinesis
o Cytoplasm splits
Animal cells = pinches in two
Plant cells = forms a cell wall down the center of
the cell
Nuclear membrane reforms
Centrioles and spindle fibers disappear
Meiosis I End Results
Two identical cells
Will go under another round of cell division
InterphaseII
Cell is not dividing
DNA is not duplicating
Prophase II
Occurring in two cells at the same time
Chromosomes double and become visible
Nuclear membrane disappears
Centrioles appear
o Act as anchors as the cell divides
Spindle fibers start to form from the centrioles
o Act as fishing line
MetaphaseI
Occurring in two cells at the same time
Chromosomes line up
o Normally in the middle of the cell
Spindle fibers attach to a single chromatid
o Not the entire chromosome as in mitosis
Anaphase I
Occurring in two cells at the same time
Chromosomes split in half
Spindle fibers contract
o Reeling in the fish
Sister chromatids pulled to different poles of cell
TelophaseI
Occurring in two cells at the same time
Cytokinesis
o Cytoplasm splits
Animal cells = pinches in two
Plant cells = forms a cell wall down the center of
the cell
Nuclear membrane reforms
Centrioles and spindle fibers disappear
Meiosis End Result
Four daughter cells
Goes through two rounds of cell division
Has only ½ of the chromosomes of the parent cell
o e.g. 23 chromosomes instead of the 46 chromosomes of a
human parent cell
End with four cells, ½ the chromosomes in each cell
Gametes (sex cells)
o Now can share genetic information