Mitosis and Meiosis

Here are some notes that I took on Mitosis and Meiosis

A chromosome is just coiled up DNA

S phase of Replication of DNA

Replicates the other side of the chromosome

 

     Sister Chromatids are connected by Centromere

     Split the sister chromatids to get two single chromatids

Mitosis

Interphase

G1

   Growth

   Normal living

S

   Protein Synthesis

   DNA Replication

G2

   Getting ready to mitosis

(M) Mitotic Phase

Mitosis

   Split the Chromosome into two

Cytokinesis

   Splitting of the cells into two separate cells

Checkpoints

Basically…

When checkpoint is down, it is like a green light

When checkpoint is up, it is like a red light

Controlling Mitosis

Caused by fluctuation between MPF activity and the enzyme Cyclin

 

Eukaryote

Process by which the contents of the eukaryotic nucleus are separated into two genetically identical packages

Start with sister chromatids in a cell nucleus

Interphase

Prophase

The nuclear envelope disintegrates

Metaphase

Sister Chromatids move toward the center

Then they attach their centromeres to spindle fibers

Anaphase

The Sister Chromatids split into single chromosomes

Pac-man...eat away at the spindle fibers which causes movements

Telephase

Nuclear envelope forms each set of chromosomes

Prokaryote

No  nucleus --> no mitosis

Binary Fission

Meiosis

At the start, each chromosome finds its homologous counterpart

Crossing over occurs.

Spindles pull the homologs apart. Sister Chromatids are not split

Repeat.

Creates four cells. Each with one copy of each chromosome.