1. 5a. The Cell Cycle
Chapters 5.1 & 5.4

2. Cells have a life cycle just like other living organisms
“Born, live, die”
Cells reproduce through division
An existing cell divides into 2 new cells
There are 2 types reproduction
Sexual
Asexual

3. Asexual Reproduction
Asexual reproduction is the creation of offspring from a single parent.
Binary fission produces two daughter cells genetically identical to the parent cell.
Binary fission occurs in prokaryotes.
parent cell
DNA
duplicates
cell begins
to divide
daughter
cells

4. There are many different forms of asexual reproduction
Budding
Fragmentation
Vegetative Reproduction
bud
Hydra
Yeast

5. There are benefits to asexual reproduction
Can be rapid
No need for other organisms
All the same DNA
Disadvantages
No genetic variation
No adaptation of species

6. Sexual Reproduction
1 new cell is from 2 existing cells

7. The Cell Cycle Eukaryotic cells do not undergo binary fission
Cells must divide to make new cells
New cells come from other existing cells
The original cell divides to become 2 new cells
The 2 new cells begin the cell cycle over again

8. The cell cycle has four main stages.
The cell cycle is a regular pattern of growth, DNA replication, and cell division.

9. The main stages of the cell cycle are gap 1, synthesis, gap 2, and mitosis.
Gap 1 (G1): cell growth and normal functions
DNA synthesis (S): copies DNA
Gap 2 (G2): additional growth
Mitosis (M): includes division of the cell nucleus (mitosis) and division of the cell cytoplasm (cytokinesis)
Mitosis occurs only if the cell is large enough and the DNA undamaged.

10. Cells divide at different rates.
The rate of cell division varies with the need for those types of cells.
Some cells are unlikely to divide (G0).