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