1. How do little elephants grow up to be BIG elephants?

3. Cell Division Large cells cannot transport nutrients across membrane
Cells will divide when they become too large
Old cells that become damaged must be replaced
Each new cell must be an exact copy of the original

4. Cells are the basic unit of structure & function of all living things…
If all living things are made of cells, what makes each organism different from other organisms?
Sea Urchin sperm cells fertilizing egg
Human sperm Cell fertilizing egg

5. DNA (deoxyribonucleic acid)
Contains the genetic instructions used in the development and functioning of all known living organisms

6. Chromosomes Compacted DNA containing cell’s genetic code
DNA must compact in order to separate when cells divide
Each chromosome has a matching pair (Homologous Pair)
One came from your mom & one came from your dad

8. Three Phases of Cell Division
Interphase – cell copies DNA and prepares for division
Mitosis – chromosomes line up in middle of cell then separate
Cytokinesis – cytoplasm divides

9. Interphase Cell growth Chromosomes are copied
Chromosomes appear as threadlike coils (chromatin)

10. Mitosis = nuclear division
The steps of mitosis ensure that each new cell has the exact same number of chromosomes as the original
Mitosis is divided into 4 phases

11. PMAT Prophase: DNA condenses (coils) into chromosomes
Animal Cell
Plant Cell
Prophase: DNA condenses (coils) into chromosomes
- copies of each chromosome stay connected
- now called sister chromatids
Metaphase: chromosomes move to the center of the cell
-spindle fibers help them align
Anaphase: sister chromatids separate & move to opposite ends of the cell (spindle fibers pull apart)
Telophase: chromosomes begin to uncoil and form two new nuclei

12. Cytokinesis
Cell membrane moves inward to create two new daughter cells
each has its own nucleus with identical DNA (chromosomes)
The two new cells are genetically identical
Animal Cell
Plant Cell

13. Cell Cycle

14. Bacteria Cell Division (Binary Fission)
Bacteria only has one circular chromosome.
The chromosome replicates then the cell divides in two.
The two daughter cells are identical to each other.

15. Viruses
infectious non-living organism that reproduces within the cells of an infected host.
It is composed of DNA inside a protein coat or capsid.