1. AIM: Why and how do cells divide.
DN: Compare and Contrast Sexual and Asexual Reproduction.
HW: Castle Learning due Monday

3. Compare the size of these organisms
Vs.
Vs.

4. Do these organisms have different size cells?No
How do organisms get so big?
Cell
Division

5. Why do cells divide rather than grow in size?XX XX XX XX XX +

6. DNA “Overload” Nucleus (DNA) loses control over the
Small Town
DNA Library
Nucleus (DNA) loses
control over the
Cell as it grows larger!!
City

7. Exchange of Materials
Cell Membrane
4 small cells have more surface area than 1 big cell
More cell membrane – less cytoplasm
Rate of Exchange Increases
Surface area

8. Surface Area
Small particles have a relatively larger surface area than large particles.
Why?
What will melt first?
The smaller chips have more surface
area.
Vs.
Ice Chips
Ice Cube
Smaller cells have more surface area and can exchange materials across
membrane more efficiently.

9. What is Cell Division? One cell divides into 2 new daughter cells
Size?

10. What happens to the chromosomes before a cell divides?
They need to replicate
What does replication mean?
To make an exact copy of the chromosome.

11. Chromosomes Replicate before the cell divides
Centromere
2 Chromatids
1 Chromosome

12. When do cells divide?
Organism Growth

13. When do cells divide?
Repair

14. What tissues in our body need to undergo a lot of cell division?
Skin
Stomach
Why? y?
Bone

15. What is Mitosis?
Mitosis is the process that divides the cell’s nucleus into two, each with a complete set of genetic material from the parent’s cell

16. What are the phases of the Cell Cycle?
Interphase
Centriole

17. Stages of Mitosis: Prophase: The chromosomes becomevi sible.
The centrioles separate and Spindle fibers begin to form.
Centriole
The nuclear membrane breaks down.
Nuclear
Membrane
Spindle Fibers

18. Stages of Mitosis: Metaphase:
The chromosomes line up across the center of the cell.
Each chromosome is connected to a spindle fiber at the centromere.

19. Stages of Mitosis: The spindle fibers separate
Anaphase:
The spindle fibers separate
the chromatids into individual
chromosomes and are they
are moved apart.

20. Stages of Mitosis: Telophase: The chromosomes gather at opposite
ends of the cell.
2) Two new nuclear membranes form.
The chromosomes lose their distinct
shapes.

21. Cytokinesis:
The cytoplasm pinches and two cells are formed.

22. What is the end result of Mitosis?
46X
46X
46X +
Parent
Daughter Cell
Daughter Cell
Is the genetic material of the
daughter cells identical to the
parent?
Chromosome Number?
The same number of
chromosomes is maintained
from one generation to the
next.
YES

23. Mitosis Phases
Prophase
Metaphase
Anaphase
Cytokinesis
Telophase

24. Plant Cells vs. Animal Cells
Which are plant cells and which are animal cells?
Animal Cells
Plant Cells
Cell Wall

25. Plant Cell vs. Animal Cell Mitosis
What process is this?
How is plant cytokinesis different
than animal cell cytokinesis?
Cytokinesis
In plants, a Cell Plate forms
across the middle of the
cell.
In an animal cell, the
cytoplasm pinches off.

26. Which phase are these cells in?
Prophase
Anaphase

27. What phase are these cells in?
Telophase
Metaphase