Objectives: I CAN…

□Sequence the events of the cell cycle

□Relate the function of a cell to its organization into tissues, organs, and organ systems

Essential Question:

• Why do cells need to divide?

RECALL……… WHAT ARE THE THREE PARTS OF THE CELL THEORY???

ALL CELLS COME FROM PREEXISTING CELLS

Examples of Cell Division– cells on the bottom of feet and back of hands

Examples of Cell Division– cuts and bruises healing

Examples of Cell Division– ivy vine growing

What happens to cells if they become too big? What process do

cells have to limit their growth?• A cell’s size can slow the rate of

diffusion

• A cell’s volume increases too fast for the surface area

• There is not enough DNA to support the protein needs of the cell

• Cell’s divide to limit their growth

•During cell division _________________ cells are produced from ______________ cell. The _________ cells are ________________ to the orginal cell.

new

one

twoidentical

What appears in the nucleus before the cells divide? What are they

made of?

• Several short, stringy structure appear

• Structures are called chromosomes made of DNA

What do chromosomes do?

• Contain DNA.

• Carries of genetic material

• Copied and passed from generation to generation

THE CELL CYCLE

INTERPHASE MITOSIS

1. Cell grows in size

2. Carries on metabolism

3. Duplicates chromosomes

4. Prepares for division

1. Follows interphase

2. Process of nuclear division

3. 2 daughter cells form

4. Daughter cells identical to parent cell

1. PROPHASE 2. METAPHASE

3. ANAPHASE 4. TELOPHASE

• New cells are produced from one cell

• Results in two identical cells

CELL DIVISION

Take Notes!Topic: Cell Reproduction

• Contain DNA, the genetic material

•Accurate transmission of chromosomes during cell division is critical.

CHROMOSOMES

Take Notes!Topic: Cell Reproduction

4th

Chromosome

Supercoil within

chromosome

Continued coiling within

supercoilHistone H1

DNA

STRUCTURE OF EUKARYOTIC CHROMOSOMES

• The cell cycle is the sequence of growth and division of a cell.

THE CELL CYCLE

• Sequence of growth and division in the cell

• Has three phases: Interphase, mitosis, and cytokinesis.

CELL CYCLE

Take Notes!Topic: Cell Reproduction

THE CELL CYCLE

•The majority of a cell’s life is spent in the growth period known as interphase.

Interphase

• Interphase, the busiest phase of the cell cycle, is divided into three parts.

DNA synthesis and replication Centrioles

replicate; cell

prepares for division

Rapid growth and metabolic activity

INTERPHASE

Part 1: cell grows and proteins are produced

Rapid growth and metabolic

activity

INTERPHASE

Part 2: cell copies its chromosomes

DNA synthesis and replication

INTERPHASE

Part 3: cell enters another shorter growth period mitochondria and other organelles are manufactured and cell

parts needed for cell division are assembled.

Centrioles replicate; cell prepares for

division

INTERPHASE

• Cell growth phase

• Cell:

• increases in size

• carries on metabolism

• duplicates chromosomes prior to division

INTERPHASE

Take Notes!Topic: Cell Reproduction

Following interphase, a cell enters its period of nuclear division called mitosis.

Mitosis

THE CELL CYCLE

Day 2

Objectives: I CAN…

□Sequence the events of the cell cycle

□Relate the function of a cell to its organization into tissues, organs, and organ systems

Mitosis

If these cells are part of the same plant, why do they all look a little different?

If the amazing process shown here did NOT happen, we wouldn’t be alive!

Mitosis

Goal: When I show this slide at the end of the day, you should be able to tell me the name of this phase of mitosis!

If you all can do it—we’ll have a raffle!

A chromosome is made of chromatin… which is made of DNA!

Nucleotides are the building blocks of DNA

Phosphate

Sugar

Base

How is a chromosome formed?

nucleus

chromosome

Chromatin

Cell cycle

ChromatinChromosome

Chromosomes duplicate!

How many pairs of chromosomes do humans have?

How many total chromosomes do humans have?

23

46

nucleus

chromosome

Chromatin

Cell cycle 23

46

Chromosome numbersEach type of eukaryote has a characteristic

number of chromosomes in the nucleus of each cell.

Examples:Humans- 46Dog- 78Potato plant- 48Cat- 38Housefly- 12Fungus- 8

nucleus

chromosome

Chromatin

Cell cycle 23

46growth

divisioninterphase

20

THE PHASES OF MITOSIS

8th

• During prophase, the chromatin coils to form visible chromosomes.

Spindle fibers

Disappearing nuclear envelope

Doubled chromosome

PHASES OF MITOSIS: PROPHASE

• The two halves of the doubled structure are called sister chromatids.

Sister chromatids

PHASES OF MITOSIS: PROPHASE

• Sister chromatids are held together by a structure called a centromere, which plays a role in chromosome movement during mitosis.

Centromere

PHASES OF MITOSIS: PROPHASE

• During metaphase, the chromosomes move to the equator of the spindle.

Centromere

Sister chromatids

PHASES OF MITOSIS: METAPHASE

• During anaphase, the centromeres split and the sister chromatids are pulled apart to opposite poles of the cell.

PHASES OF MITOSIS: ANAPHASE

• During telophase, two distinct daughter cells are formed. The cells separate as the cell cycle proceeds into the next interphase.

Nuclear envelope reappears

Two daughter cells are formed

PHASES OF MITOSIS: TELOPHASE

Review Day!!!!

Objectives: I CAN…

□Sequence the events of the cell cycle through a review session

ReviewGrab your white board and the note sheet on mitosisANSWER THE FOLLOWING:

1. What are the 3 phases of the cell cycle?Interphase, Mitosis, Cytokinesis

2. Most of the cell’s life is spent in which phase of the cell cycle ?INTERPHASE

3. What is the purpose of the cell cycle?

4. What is the longest phase of the cell cycle?

Growth and division of cells

Interphase

5. What are the 3 phases of the cell cycle?

6. What are the 4 stages of mitosis?

Interphase, Mitosis, Cytokinesis

Prophase, Metaphase, Anaphase, Telophase

7. The phase of mitosis pictured below?

METAPHASE

8. The phase of mitosis pictured below?

PROPHASE

9. The phase of mitosis pictured below?

TELOPHASE

10. The phase of mitosis pictured below?

ANAPHASE

11. What is the purpose of cytokinesis?

12. How long is the cell cycle of the average human cell?

To divide the cytoplasm and cell membrane

20 hours

13. How many chromosomes does the average human have?

14. What is the picture of all of the cell’s chromosomes called?

46

KARYOTYPE

15. What disease occurs when cell growth is out of control?

16. What is one cause of uncontrolled cell growth?

cancer

Tobacco products, pollution, ultraviolet radiation (sun)

17. What happens during interphase?

18. What happens during prophase?

Cells prepare to divide, cells grow, multiply chromosomes

Chromosomes condense and become visible

19. What happens during metaphase?

20. What happens during anaphase?

Chromosomes align at equator

Sister chromatids separate

21. What happens during telophase?

22. Give an example of when mitosis (cell division) is needed?

Nuclear membrane reforms around each set of chromosomes

Cut skin, growing (plants or animals), hair or nail growth, cell repair

1. Cell Cycle

B. Sequence of growth and division of a cell

2. Sister ChromatinE. Make up the 2 halves of the double stranded chromosome and the DNA they contain are exact copies of each other

3. InterphaseD. Longest phase of the cell cycle, where the cell grows, synthesizes DNA, and prepares for division

4. MitosisF. Nuclear cell division, forming two daughter cells each containing a complete set of chromosomes

5. Daughter cells

C. Produced at the end of mitosis, identical to the parent cell

6. ChromosomeA. Contain DNA and carry the genetic information material that is passed from cell to cell

7. What are the 3 phases of the cell cycle? (in order)

Interphase, Mitosis, Cytokinesis

8. Which of these cycles does the cell spend most of its time in?

Interphase

9. What are the 4 phases of mitosis? (in order)

Prophase, Metaphase, Anaphase, Telophase

10. What disease is caused by uncontrolled cell growth?

Cancer

11. Cell growth occurs

Interphase

12. Nuclear division occurs

Mitosis

13. DNA synthesis occurs

Interphase

14. Cytoplasm divides immediately after this

period

Mitosis

15. Chromosomes are duplicated

Interphase

16. Two distinct daughter cells are

formed

Telophase

17. The chromosomes move to the equator of

the cell

Metaphase

18. The chromatin coils to form visible chromosomes

Prophase

19. The centromeres split and the sister

chromatids are pulled apart to opposite poles

of the cell

Anaphase

A. Prophase

B. Anaphase

C. Telophase

D. Metaphase

Sister chromatidsCentromere

EXTRA CREDIT