Cell Division
Review
What the four major stages
of the cell cycle?
Which stages make up
interphase?
What occurs during each
stage of the cell cycle?
• G1
•S
• G2
•M
• G1- growth, replicate organelles, normal
functions
• S- DNA synthesis
• G2- Additional growth
• M- Mitosis and cytokinesis
* What is the purpose of mitosis? What is the
end result?
* What kind of human cells do mitosis?
* What are the 4 stages of mitosis?
What occurs during each
stage of mitosis
• Prophase
• Metaphase
• Anaphase
• Telophase
•Prophase- DNA condenses into
chromosomes, nuclear envelope breaks
down
•Metaphase- Spindle fibers attach
chromosomes and align them in center of
cell
•Anaphase- sister chromatids separate to
opposite poles
•Telophase- nuclear membrane starts to
reform, chromosomes start to uncoil
What is
cytokinesis?
What is binary
fission?
• Binary fission- prokaryotic, asexual
reproduction, much simpler than mitosis
* What is the purpose of meiosis? What is the
end result?
* Meiosis is associated with what kind of
human cells?
* What are the stages of meiosis?
* What is the difference between homologous
chromosomes and sister chromatids?
*What is the main purpose of meiosis I?
meiosis II?
Meiosis I
• Main idea: divides homologous chromosomes
• Prophase I- homologous chromosomes start to pair up, nuclear
membrane breaks down. Crossing over occurs!
• Metaphase I- spindle fibers attach, homologous chromosomes
pair up on either side of cell equator.
• Anaphase I- homologous chromosome pulled to opposite poles
• Telophase I- spindle fibers disassemble, cell does cytokinesis
• End result- 2 genetically unique haploid cells with duplicated
chromosomes
Meiosis II
• Main idea: divides sister chromatids
• Prophase II- homologous chromosomes start to pair up, nuclear
membrane breaks down
• Metaphase II- spindle fibers align chromosomes along equator
• Anaphase II- sister chromatids pulled apart to opposite poles
• Telophase II- nuclear membrane reforms, cell does cytokinesis
• End result: 4 genetically unique haploid cells
Unchecked cell division is
known as what?
• Cancer