The document describes the process of cell division through mitosis and meiosis. It explains the stages of mitosis (interphase, prophase, metaphase, anaphase, telophase, and cytokinesis). Interphase is the longest stage and includes DNA replication. Meiosis results in four haploid cells through two rounds of division, while mitosis produces two identical diploid daughter cells. Meiosis is important for sexual reproduction as it combines the haploid cells to create a diploid offspring.

1. The Case of the Dividing Cell
By Lauren and Robert

2. Life Cycle of a Cell - Mitosis

Interphase

Prophase

Metaphase

Anaphase

Telophase

Cytokinesis

3. Interphase

Longest stage

3 stages: G1, S, G2

G1 – cell accelerates biochemical processes that
were slowed down by mitosis

S – DNA replication

G2 – chromosomes condense

4. Prophase

Spindle fiber is formed

Centrioles are duplicated

Nuclear envelope begins to break up

5. Metaphase

Chromosomes line up in center of cell

6. Anaphase

Chromosomes split

Move to opposite sides of the cell

7. Telophase

Chromosomes are completely separate

Nuclear envelope begins to reform

8. Cytokenesis

Cells split apart

Two daughter cells result

9. Cell Division –
Prokaryotes vs. Eukaryotes

Prokaryotes use binary
fission

DNA replicates; strands
attach to membrane

Cell elongates; DNA
separates

Cell wall and membrane
grow from the center of
cell causing division

Eukaryotes must go
through all the steps of
either mitosis or meiosis

10. Meiosis

1st
half (Meiosis 1) is the same as mitosis

2nd
round skips the DNA replication

4 haploid daughter cells result

11. Mitosis vs. Meiosis

Mitosis

Asexual
reproduction

2 diploid cells result

Meiosis

Sexual reproduction

4 haploid cells result

12. Crossing Over

Exchange of genetic material between
homologous chromosomes

Occurs during Prophase 1 of Meiosis

However, similarities in sequences can
cause non-homologous chromosomes to
cross over with each other.

13. Why is Meiosis Important for
Sexual Reproduction?

Sexual reproduction uses two haploid cells

They combine to produce a diploid offspring

If the cells didn't divide a second time to
make a haploid, the offspring would have
double the diploid