1. Answer the following in your notebook:
Warm-up Questions
Answer the following in your notebook:
List the 2 types of unicellular organisms?
What cell type is found in multicellular organisms?
Name the 4 levels of organization from small-LARGE.

2. 10–1 Cell Growth Limits to Cell Growth DNA “Overload”
Exchanging Materials
Ratio of Surface Area to Volume
Cell Division

3. Limits to Cell Growth
The cells of both the young and old are no different. They are still the same sized cells, there are just more of them as we grow.
There are 2 reasons why cells divide rather than grow indefinitely:
The larger a cell become, the harder it is for the DNA to keep up cell functions.
Larger cells have trouble transporting nutrients in and waste out through the cell membrane.

4. DNA “Overload”
As you recall, information on how a cell operates is found in DNA. As a cell grows, its DNA does not grow, it stays the same size.
If you compare DNA to a library:
In a small cell, it is a short/easy distance to travel from the cell membrane to the nucleus to check out a book.
But in a very large cell, it would take a long time to travel from the cell membrane to the nucleus, you may even get lost along the way. So it would be difficult to check out a book.

5. Exchanging Materials
Food, oxygen, and nutrients enter into a cell through the cell membrane. And waste exits through the cell membrane.
The rate at which this occurs, depends on the surface area of the cell membrane. The rate at which food is used and waste release depends on the cell’s volume/size.

6. Ratio of Surface Area to Volume
Imagine a cell is shaped like a cube. If a cell has length of 1cm, its surface area = length × width × number of sides,
Example of Surface Area: 1cm × 1cm × 6 = 6 cm2.
Volume of a cell = length × width × height
Example of Volume: cm × 1cm × 1cm = 1cm3
To obtain the ratio of surface area to volume, divide the surface area by the volume. In this case, the ratio of surface area to volume of a cell would be 6 / 1, or a ratio of 6 : 1.
Note that the volume increases much more rapidly than the surface area, causing the ratio of surface area to volume to decrease. This decrease creates serious problems for the cell.

7. Ratio of Surface Area to Volume

8. QUIZ NEXT CLASS!!! Cell Theory Organelles Cell Transport
What to study:
Cell Theory
Organelles
Cell Transport

9. Surface Area & Volume Activity
Use ruler and scissors to make 3 cell sizes.
Each person makes a different sized cell.
Write your name, label dimensions of your cube, then tape together.
Calculate the surface volume to area ratios!!! Answer all worksheet questions.
When finished, turn in worksheet!!!

10. Homework Study for the Quiz Lab next class 
Continue working on your Cell Membrane project (Due 17th & 20th)

11. Answer the following in your notebook:
Good morning! 
Answer the following in your notebook:
Are the cells in a baby the same size as the cells in an adult?
Give 2 reasons why cells divide instead of growing larger.
Which increases at a faster rate: surface area or volume?
List the 2 types of unicellular organisms?
What cell type is found in multicellular organisms?
Name the 4 levels of organization from small-LARGE.

12. 10–2 Cell Division Cytokinesis Chromosomes The Cell Cycle
Events of the Cell Cycle
Mitosis
Prophase
Metaphase
Anaphase
Telophase
Cytokinesis

13. Cell Division
Before it becomes too large, a growing cell divides forming into two identical “daughter cells”. This process is called cell division.
Before cell division occurs, the cell replicates/copies, all of its DNA. This replication of DNA solves the problem of information storage because each daughter cell gets one complete set of genetic information. Thus, each daughter cell receives its own genetic “library.”
Cell division also solves the problem of increasing size by reducing cell volume. Each daughter cell has an increased ratio of surface area to volume. This allows efficient exchange of materials with the cell.

14. The Cell Cycle
Most of a cell’s life is spent in a resting/growing phase called “interphase”, where it goes through all the normal cell functions. Before a cell replicates itself, much must happen to prepare the cell. We will call of of the events of a cell’s life the Cell Cycle.
After a cell divides, each daughter cell will undergo the same cell cycle of growth and division.
The cell cycle consists of 4 parts:
G1: the cell begins to grow and doubles its organelles
S: DNA is replicated (synthesized)
G2: organelles for division are made (centrioles & spindle fibers)
M: mitosis – cell division

15. Chromosomes
In eukaryotic cells, the genetic information that is passed on from one generation of cells to the next is carried by chromosomes. Chromosomes are made up of DNA - which carries the cell’s coded genetic information and proteins. The cells of every organism have a specific number of chromosomes. Humans have 46 chromosomes!
Chromosomes are not visible in most cells except during cell division. This is because the DNA and protein molecules that make up the chromosomes are spread throughout the nucleus as chromatin. At the beginning of cell division, the chromosomes condense into an “X” shape.
Before cell division, each chromosome replicates (is copied). The X-shaped chromosome is made of 2 identical “sister chromatids”. Each pair is attached in the center, called the “centromere”.

16. Cell Cycle includes M phase (Mitosis) Interphase is divided into
G1 phase
S phase
Prophase
G2 phase
Metaphase
Telophase
Anaphase

17.  The Cell Cycle
G1 phase
M phase
S phase
G2 phase

18. Mitosis
There a 4 phases of mitosis: prophase, metaphase, anaphase, and telophase (PMAT).
Actual cell division can last from a few minutes to a few days, depending on the type of cell.

19. Think-pair-share!
Its ok for a cell not to divide, they can grow larger indefinitely.
All types of cells go through mitosis.
The 4 phases of the cell cycle are the same as the 4 phases for mitosis.

20. Prophase
Prophase is the 1st and longest phase of Mitosis. During prophase the chromosomes are visible inside the nucleus.
Centrioles separate and move towards opposite ends of the nucleus where they attach to spindle fibers (made of microtubules). The nuclear membrane disappears and the spindle fibers attach to the centromere (center) of the sister chromatid pairs (chromosomes).

21. Metaphase
The 2nd phase of Mitosis, only last a few seconds. During metaphase, the chromosomes line up across the center of the cell. Spindle fibers are connected from the centromere towards the opposite ends of the cell.

22. Anaphase
The 3rd phase of Mitosis. The spindle fibers are pulled towards opposite sides of the cell, causing the centromeres and sister chromatids to separate into individual chromosomes.
The chromosomes continue to move until they have separated into two groups at opposite ends of the cell (poles).
Anaphase ends when the chromosomes stop moving.

23. Telophase
The 4th phase of Mitosis. The chromosomes begin to unwind into chromatin and a new nuclear envelope forms around them. The spindle fibers and centrioles disappear, and the nucleolus becomes visible.
The process of cell division is not yet completed, there is one more step.

24. Cytokinesis
As a result of mitosis, two nuclei - each with a duplicate set of chromosomes - are formed within the cytoplasm of a single cell. All that remains to complete the M phase of the cycle is cytokinesis, the division of the cytoplasm itself.
During cytokinesis, the cell membrane is drawn inward until the cytoplasm is pinched into two equal parts. Each part contains its own nucleus and organelles.
The result is two new, identical daughter cells.

25. Bonus Info NOT in notes:
Cells that divide too quickly when they’re not supposed to (they go rogue), or divide incorrectly, can form into cancer!
Our bodies have a natural check point system in place during mitosis: if they notice something is wrong they will self- terminate the rogue cells.
This is known as Apoptosis.

26. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

27. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

28. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

29. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

30. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

31. Figure 10–5 Mitosis and Cytokinesis
Spindle forming
Centrioles
Nuclear envelope
Chromatin
Centromere
Centriole
Chromosomes (paired chromatids)
Interphase
Prophase
Spindle
Cytokinesis
Centriole
Metaphase
Telophase
Individual chromosomes
Anaphase
Nuclear envelope reforming

32. A fun way to remember Mitosis!
Hand gestures to remember the phases of Mitosis (cell division).

33. Summary of ch.10
Please spend the next 2 minutes writing a summary about The Cell Cycle & Mitosis in your notes.

34. Matching Activity Make a 3x3 square with your group
Match Vocab to Definition

35. Mitosis Pictures
Fill in blanks and color pictures

36. Homework
The Cell Cycle (worksheet)

37. Analogy Groups!
In your groups, you’ll be assigned one of the phases of cell division.
Directions: 5 minutes!
Come up with an analogy to help everyone remember what is occurring during your phase.
Act out your analogy safely!