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 two identical

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 INTERPHASEMITOSIS 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 supercoil Histone 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

Chromatin Chromosome

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 numbers Each type of eukaryote has a characteristic number of chromosomes in the nucleus of each cell. Examples: Humans- 46 Dog- 78 Potato plant- 48 Cat- 38 Housefly- 12 Fungus- 8

nucleus chromosome Chromatin Cell cycle growth division interphase 20

THE PHASES OF MITOSIS 8th

Section 8.2 Summary – pages During prophase, the chromatin coils to form visible chromosomes. Spindle fibers Disappearing nuclear envelope Doubled chromosome PHASES OF MITOSIS: PROPHASE

Section 8.2 Summary – pages The two halves of the doubled structure are called sister chromatids. Sister chromatids PHASES OF MITOSIS: PROPHASE

Section 8.2 Summary – pages 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

Section 8.2 Summary – pages During metaphase, the chromosomes move to the equator of the spindle. Centromere Sister chromatids PHASES OF MITOSIS: METAPHASE

Section 8.2 Summary – pages During anaphase, the centromeres split and the sister chromatids are pulled apart to opposite poles of the cell. PHASES OF MITOSIS: ANAPHASE

Section 8.2 Summary – pages 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

Review Grab your white board and the note sheet on mitosis ANSWER 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 Chromatin E. Make up the 2 halves of the double stranded chromosome and the DNA they contain are exact copies of each other

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

4. Mitosis F. 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. Chromosome A. 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 chromatids Centromere EXTRA CREDIT