Cell Division

3 reasons cells need to divideReason Why

3 reasons cells need to divideReason Why

Growth

Repair

Reproduction

3 reasons cells need to divideReason Why

Growth An individual cell cannot grow very large so it has to split into two cells with the same function

Repair

Reproduction

3 reasons cells need to divideReason Why

Growth An individual cell cannot grow very large so it has to split into two cells with the same function

Repair Cells don’t live as long as we do. We need to replace cells that die.

Reproduction

3 reasons cells need to divideReason Why

Growth An individual cell cannot grow very large so it has to split into two cells with the same function

Repair Cells don’t live as long as we do. We need to replace cells that die.

Reproduction Organisms made of one cell need to divide to make new organisms

Cell structures needed for cell division

• Nucleus: The control center of the cell- It directs cell division

- Contents of the nucleus for cell division

Cell structures needed for cell division

• Nucleus: The control center of the cell- It directs cell division

- Contents of the nucleus for cell division- Chromosomes: The material that directs all the

activities of the cell.- Made of DNA (deoxyribonucleic acid)

- Nucleolus: Makes the ribosomes and ships them out to the cell.

Chromosomes and DNA

What is DNA made of?

• The structure of DNA looks like a twisted ladder. – The sides of the ladder are made from sugar-

phosphate chains– The steps of the ladder are made from two of the

four nitrogenous bases• Adenine • Cytosine • Thymine• Guanine

What is DNA made of?

.

Which nitrogenous bases pair up?

DNA Replication

• Before a cell divides it needs to make sure it has two copies of DNA. To make this copy it unzips and new pieces ofDNA fill in the other sides