Why should your body grow new cells?
In the time it takes you to read this sentence how many new cells do you think your body will produce?
Millions!Your stomach alone has so much
acid that the cells in the lining have to be replaced every few days!
Cytokinesis
Mitosis
CentromereChromatids
BinaryFission
HomologousChromosomes
Chromosomes
The CellCycle
Cell Cycle
• Different stages of a cell’s life• Cycle begins when cell is formed…ends when
cell divides to make a new cell.
Ex. You go thru stages of life so does a cell!
To
Binary Fission
• Happens in Prokaryotic cells• Means “splitting into 2 parts”• Results in a copy of bacteria
How do Eukaryotic cells divide?
Mitosis
• The way organisms replace damaged and old cells or grow new cells.
Mitosis
• Making or replacing cells involves copying and moving DNA to the new cell.
Chromatids• Are the ½ the chromosome. • Centromere: is the connection part of the X.
Centromere
Chromosomes• DNA organized into structures• Vary in organism Ex. Humans=46, flies=8
1 “X”
Homologous Chromosomes
• Are 2 strands of chromosomes placed together to form an XX.
Pre-phase: Interphase
• Cell grows and copies organelles & chromosomes
• Has loose DNA
• The 2 copies are called chromatids.
Mitosis.asx
Mitosis: Prophase• Nuclear membrane breaks apart• Centrioles move to opposite sides• Fibers form bet. the 2 centrioles and centromeres
catch the DNA.
Mitosis: Metaphase
• Chromosomes begin to line up
Mitosis: Anaphase
• Chromatids separate and move to centrioles on fibers.
Mitosis: Telophase
• Nuclear membrane forms around chromosomes.
Post-Phase: Cytokinesis
• Is when the cytoplasm splits in 2.• This ends the cell cycle.
Sentence What happens in cell
Cats copy
Can catch
Lick Line up
Pop Pull apart
Rocks Reform
Carefully cytokinesis