MAKE A KWL CHART ABOUT CANCER (WRITE ON 1 SIDE OF

THE BLANK PAPER)

What I already know

about cancer

What I want to know

about cancer

What I learned about

cancer

CELL CYCLE• Introduction Video

• http://www.dnalc.org/view/15536-Cell-division-tumor-growth-and-metastasis-3D-animation-with-basic-narration.html

OBJECTIVES• Explain the major stages of the cell cycle and cellular

division

• Describe specific events occurring in each of the phases of cellular division including cytokinesis

• Explain how cellular division functions to form new cells and maintain complex organisms

• Describe the role of mitosis in asexual reproduction and explain how it maintains the chromosome number, and how it may contribute to limiting genetic variation

• Explain how a mutation might cause the cell cycle to be altered to allow for uncontrolled cell growth

• Relate the development of cancer (uncontrolled growth) to mutations that affect the proteins that regulate the cell cycle

ESSENTIAL QUESTION

• What can you infer about how cell division in a normal cell compares to cell division in a cancer cell?

THE CELL CYCLE

5

CELL CYCLE – WRITE THIS DOWN!

6

GAP 1 (G1)

Cell growth

Normal FunctionsReplications of organelles

7

SYNTHESIS (S)

Copies DNA

GAP 2 (G2)

Additional growth and carrying out normal functions

MITOSIS

Cell Division

1. Prophase

2. Metaphase

3. Anaphase

4. Telophase

5. Cytokinesis

TWO MAIN PHASES IN THE CELL CYCLE

Mitosis

Interphase

CHROMOSOME STRUCTURE

• One long continuous thread of DNA

• DNA wraps around proteins called histones

• DNA and histones form chromatin, which looks like spaghetti, during interphase

• Chromosomes condense tightly for mitosis. Because they are duplicated, they look like an X

1. INTERPHASE

• Copies DNA, grows, and duplicates organelles

nucleus

cell

DNA

2. PROPHASE

• Chromosomes condense, nuclear envelope breaks down, spindle fibers form

nucleus

cell

3. METAPHASE

• Spindle fibers align chromosomes along the cell equator (middle of cell)

4. ANAPHASE

• Chromatids separate to opposite sides of cell

5. TELOPHASE• Nuclear membranes start to form around

the chromosomes, chromosomes begin to uncoil, spindle fibers fall apart

6. CYTOKINESIS• Divides the cytoplasm between two

daughter cells

NEW “DAUGHTER” CELLS

• Get 2 exact copies of original cells

• same DNA

• “clones”

MITOSIS IN PLANT CELL

onion root tip

MITOSIS• In the cell cycle

•Animals have cleavage furrow that bends in to divide

•Plants have cell plate that divides

BINARY FISSION• Asexual reproduction of a single-

celled organism by division into two equal parts

• Takes place in Prokaryotes

• Ex. bacteria

WHAT ARE SOME ADVANTAGES AND/OR DISADVANTAGES TO

ASEXUAL REPRODUCTION?

CELLS DIVIDE AT DIFFERENT RATES

• Rates of cell division vary widely and are linked to the body’s need

• The length of G1 varies most widely among cell types

CELL SIZE IS LIMITED

• If cells were too small, they could not contain all the organelles necessary for life.

• If cells were too large, they could not move enough materials across the membrane surface.

• To maintain a suitable size, cell growth and division must be coordinated.

REGULATION OF CELL CYCLE

What would happen if the cell cycle was not regulated (i.e. something to control how often it divides)?

INTERNAL FACTORS

• Checkpoints are located during the G1, G2, and M phase of the cell cycle

• If something is not right, the cell will not continue in the cycle and will wait until the issue is fixed

EXTERNAL FACTORS

•Cell to cell contact and chemical signals/growth factors can both influence a cell to divide

CARCINOGENS

•Substances that produce or promote the development of cancer

•Examples: tobacco smoke, air pollutants, radiation, and viruses

CANCER CELLS

•characterized by uncontrolled cell division;

•continue to grow despite cell-cell contact or lack of growth factors

TUMORS

• Disorganized clumps of cancer cells that do not carry out specialized functions needed by the body

APOPTOSIS

• Programmed cell death

• Plays a role in normal development

• Rids the body of unhealthy cells

COOKIE ACTIVITY

• Grab 3 cookies

• Take them apart, try to get icing on both sides of the oreos

• Grab 16 pieces of little papers

• Create chromosomes from the papers

• Demonstrate prophase, metaphase, anaphase and telophase using the cookies as the cells and cutouts as the chromosomes