1. Cell Division
Chapter 3

2. Do Now What happens when you get a cut?
Use pictures, symbols, words, etc. to explain.

3. Objectives
To list and explain the different reasons cells must divide.
To define chromosomes and all their counterparts.
To determine different things that limit cell size.

4. Cellular Division A. Cell division is involved in many functions.
1. Unicellular division= “binary fission”
2. Multicellular division = “mitosis”

5. Binary Fission

6. Multicellular Division

7. DO NOW
How big is a cell?
Why can’t a cell get too big?

8. Why do we need cell division?
Cell division is involved in many processes.
a. Growth- get bigger
b. Development- change
c. Repair- fix damaged/old cells, cuts
d. Reproduction- make new cells

9. B. Cell Division is involved in growth, development, and repair…
All organisms start as a single cell
Growth- limited by surface area ( needs high ratio of surface area to volume)
High SA allows nutrients in & waste out

10. Surface area vs. volume

11. Cellular Growth
Ratio of Surface Area to Volume
Area
Volume

12. Equations Surface Area: (2 x L x W) + (2 x L x H) + (2 x H x W)
Volume:
L x W x H

13. Do Now Which cell has a bigger Surface Area to Volume Ratio?
2 x 3 x 2 OR 4 x 1 x 1
Which cell is more efficient?

14. B. Cell Division is involved in growth, development, and repair…
c. Development
i. makes cells that are specialized
ex: nerve, blood, muscle, bone

15. B. Cell Division is involved in growth, development, and repair…
i. healing of cuts and wounds
ii. Cells divide to fill space and close wound.

16. Chromosome Activity
Worksheet

17. C. The genetic material of eukaryotic cells is organized in chromosomes.
DNA (Deoxyribonucleic Acid)
Discovered by Watson, Crick, and Franklin
1. purpose: hereditary material (what makes you you!)
Shape: Double Helix
1. Repeating units of nucleotides

18. C. The genetic material of eukaryotic cells is organized in chromosomes.
c. How does all of this DNA fit in a cell?
1. Loose= chromatin
2. Coiled around proteins- chromosome
a. chromosome = 2 chromatids
-connected by a centromere
50250

19. o
Do Now
Label the parts of the chromosome.