1. CELL Reproduction (Division)
Georgia Performance Standards: Compare and contrast cell reproduction (mitosis) in eukaryotes and prokaryotes
Essential Questions:
EQ: Why is mitosis necessary in cell reproduction?
EQ: What happens when mitosis goes wrong?

2. What’s wrong with big cells?
Chapter 9
Cellular Reproduction
What’s wrong with big cells?
As the cell grows, its volume increases much more rapidly than the surface area.
The cell might have difficulty supplying nutrients and expelling enough waste products.

3. Ratio of Surface Area to Volume in Cells
Section 10-1
Cell Size
Surface Area (length x width x 6)
Volume
(length x width x height)
Ratio of Surface Area to Volume
Review: The larger a cell becomes, the more demands the cell places on its DNA and the more trouble the cell has moving enough nutrients and wastes across the cell membrane.
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4. Transport of Substances is slow for big cells
Chapter 9
Cellular Reproduction
Transport of Substances is slow for big cells
Substances move by diffusion or by motor proteins.
Diffusion over large distances is slow and inefficient.
Small cells maintain more efficient transport systems.

5. Cellular Communications are compromised in big cells
Chapter 9
Cellular Reproduction
Cellular Communications are compromised in big cells
The need for signaling proteins to move throughout the cell also limits cell size.
Cell size affects the ability of the cell to communicate instructions for cellular functions.

6. Cell Division
What do you think would happen if a cell were simply to split into two, without any advance preparation?
Would each daughter cell have everything it needed to survive?

7. Every cell must first copy its genetic information before cell division begins.
Each daughter cell then gets a complete copy of that information.
Cell division is called mitosis
Each cell has identical DNA

8. Cell Division
In eukaryotic cells, the genetic information is carried by chromosomes.
Chromosomes are made up of DNA and protein.
At the beginning of cell division, each chromosome consists of two identical “sister” chromatids.
Each pair of chromatids is attached at an area called the centromere.

9. Cell division prevents the cell from becoming too large.
Chapter 9
Cellular Reproduction
The Cell Cycle
Cell division prevents the cell from becoming too large.
The cell reproduces so that you grow and heal certain injuries.
Cells reproduce by a cycle of growing and dividing called the cell cycle.

10. The Cell Cycle
During the cell cycle, a cell grows, prepares for division, and divides to form two daughter cells, each of which then begins the cycle again.

11. Chapter 9
Cellular Reproduction
9.1 Cellular Growth
Interphase is the stage during which the cell grows, carries out cellular functions, and replicates.
Mitosis is the stage of the cell cycle during which the cell’s nucleus and nuclear material divide.
Cytokinesis is the method by which a cell’s cytoplasm divides, creating a new cell.

12. The Cell Cycle Section 10-2 G1 phase M phase S phase G2 phase
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13. The Stages of Interphase
Chapter 9
Cellular Reproduction
9.1 Cellular Growth
The Stages of Interphase
The first stage of interphase, G1
The cell is growing, carrying out normal cell functions, and preparing to replicate DNA.

14. The Second Stage of Interphase, S
Chapter 9
Cellular Reproduction
9.1 Cellular Growth
The Second Stage of Interphase, S
The cell copies its DNA in preparation for cell division.

15. The Third Stage of Interphase, G2
Chapter 9
Cellular Reproduction
9.1 Cellular Growth
The Third Stage of Interphase, G2
The cell prepares for the division of its nucleus.

16. Mitosis: Four Stages
Prophase
Metaphase
Anaphase
Telophase

17. The cell’s chromatin tightens.
Chapter 9
Cellular Reproduction
9.2 Mitosis and Cytokinesis
The Stages of Mitosis
Prophase
The cell’s chromatin tightens.
Sister chromatids are attached at the centromere.
Spindle fibers form in the cytoplasm.

18. The nuclear envelope seems to disappear.
Chapter 9
Cellular Reproduction
9.2 Mitosis and Cytokinesis
The nuclear envelope seems to disappear.
Spindle fibers attach to the sister chromatids.

19. They line up in the middle of the cell.
Chapter 9
Cellular Reproduction
9.2 Mitosis and Cytokinesis
Metaphase
Sister chromatids are pulled along the spindle apparatus toward the center of the cell.
They line up in the middle of the cell.

20. The microtubules of the spindle apparatus begin to shorten.
Chapter 9
Cellular Reproduction
9.2 Mitosis and Cytokinesis
Anaphase
The microtubules of the spindle apparatus begin to shorten.
The sister chromatids separate.
The chromosomes move toward the poles of the cell.

21. The chromosomes arrive at the poles and begin to relax.
Chapter 9
Cellular Reproduction
9.2 Mitosis and Cytokinesis
Telophase
The chromosomes arrive at the poles and begin to relax.
Two new nuclear membranes begin to form and the nucleoli reappear.
The spindle apparatus disassembles.

22. Cytokinesis
As a result of mitosis, two nuclei—each with a duplicate set of chromosomes—are formed, usually within the cytoplasm of a single cell.
Cytokinesis: the division of the cytoplasm itself, ends mitosis.
Cytokinesis usually occurs at the same time as telophase.

23. Cytokinesis In most animal cells In plants cells
the cell membrane is drawn inward until the cytoplasm is pinched into two nearly equal parts.
Each part contains its own nucleus and cytoplasmic organelles.
In plants cells
a structure known as the cell plate forms midway between the divided nuclei
The cell plate gradually develops into a separating membrane.
A cell wall then begins to appear in the cell plate.

24. Chapter 9
Cellular Reproduction

25. Concept Map Cell Cycle Section 10-2 M phase Interphase (Mitosis)
includes
M phase
(Mitosis)
Interphase
Cytokinesis
is divided into
is divided into
G1 phase
S phase
Prophase
G2 phase
Metaphase
Telophase
Anaphase
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26. Prokaryote (Bacteria) Structure
Bacteria and Viruses
Prokaryote (Bacteria) Structure
Prokaryotes are microscopic, unicellular organisms.
They have some characteristics of all cells, such as DNA and ribosomes.
Lack a nuclear membrane and other membrane-bound organelles

27. Cell Division
In prokaryotes, the cell first replicates its genetic information before cell division begins. Then the cell splits into two parts.

28. Reproduction of Prokaryotes: 2 Types
Bacteria and Viruses
Reproduction of Prokaryotes: 2 Types
Binary Fission: Division of a cell into two genetically identical cells
Conjugation: Two prokaryotes attach to each other and exchange genetic information.

29. Mitosis Summary
Every cell must first copy its genetic information before cell division begins.
Cell division is called mitosis
Mitosis produces two genetically identical daughter cells with 2 sets of chromosomes (diploid)

30. Checkpoint Questions 1. Name the 3 main events of the cell cycle.
2. Describe what happens during each of the four phases of mitosis.
3. Describe what happens during interphase.
4. What are chromosomes made of?
5. Compare and contrast how prokaryotic and eukaryotic cells divide?
6. Compare and contrast cytokenesis in plant and animal cells.

31. What happens when mitosis goes wrong?

32. Chapter 9
Cellular Reproduction
Normal Cell Cycle
Different cyclin/CDK combinations signal other activities, including DNA replication, protein synthesis, and nuclear division throughout the cell cycle.

33. Quality Control Checkpoints
Chapter 9
Cellular Reproduction
Quality Control Checkpoints
The cell cycle has built-in checkpoints that monitor the cycle and can stop it if something goes wrong.
Spindle checkpoints also have been identified in mitosis.

34. Abnormal Cell Cycle: Cancer
Chapter 9
9.3 Cell Cycle Regulation
Abnormal Cell Cycle: Cancer
Cancer is the uncontrolled growth and division of cells.
Cancer cells can kill an organism by crowding out normal
cells, resulting in the loss of tissue function.

35. Chapter 9
Cellular Reproduction
Causes of Cancer
The changes that occur in the regulation of cell growth and division of cancer cells are due to mutations.
Various environmental factors can affect the occurrence of cancer cells.

36. Apoptosis Programmed cell death
Chapter 9
Cellular Reproduction
Apoptosis
Programmed cell death
Cells going through apoptosis actually shrink and shrivel in a controlled process.

37. Chapter 9
Cellular Reproduction
9.3 Cell Cycle Regulation
Stem Cells
Unspecialized cells that can develop into specialized cells when under the right conditions

38. Chapter 9
Cellular Reproduction
Embryonic Stem Cells
After fertilization, the resulting mass of cells divides repeatedly until there are about –150 cells. These cells have not become specialized.

39. Chapter 9
Cellular Reproduction
Adult Stem Cells
Found in various tissues in the body and might be used to maintain and repair the same kind of tissue
Less controversial because the adult stem cells can be obtained with the consent of their donor

40. Stem Cell Movie: