MITOSIS

Think About This… What is this? What IS cancer?? What are some causes? What are some reasons for cell division? How do you think a cell would accomplish

this task?

SO WHY LEARN ABOUT CELL DIVISION??

Growth Cancer- uncontrolled growth Cells have given life spans; need to

replace! Lining of esophagus 2-3 days Lining of small intestine 1-2 days Skin 2-4 weeks

Stem Cells

All Cells Come From Cells One concept of the cell theory we just

learned about! All organisms reproduce their own kind…

Asexual Reproduction Sexual Reproduction

Types of Cell Division We Will Learn About

Mitosis- Division of somatic cells (body cells)

Meiosis- Creation of gametes (sex cells)

Lab- You Are a 19th Century Cell Biologist In this lab, you will assume the role of a biologist

in the mid-1890s. You are fascinated by the power of the microscope to reveal the inner workings of living cells. The invention of the compound microscope, along with new stains, make it possible for you to see cell structures that no one has ever seen before. You plan to collaborate with your colleagues to discover the events of cell division.

Lab- You Are a 19th Century Cell Biologist

Things you know right now: 1) The cell has many organelles. 2) The nucleus seems to be pretty important. 3) There seem to be “structures” inside the

nucleus that undergo changes during cell division (chromosomes).

Lab- You Are a 19th Century Cell Biologist

1) Obtain a microscope and a slide of onion root tip.

2) Focus under low power.

MITOSIS-ONION ROOT TIP 3) Move to high power; only adjust here

with the fine focus.

Lab- You Are a 19th Century Cell Biologist 4) Select one cell whose chromosomes are

clearly visible & sketch in the box. 5) Look around and select 4 other cells whose

internal appearances are different and sketch them as well.

6) Try and place your sketches in order from 1-5.

7) Check your answers with Mrs. Romano… how many did you get right??

Lab- You Are a 19th Century Cell Biologist

8) Identify the phases of cell division. 9) Count the number of cells in your slide in

each stage of cell division. 10) Answer the analysis questions.

MITOSIS

Review- Cell Parts TERMS TO KNOW:

Nucleus Nuclear envelope Centriole Spindle Fiber Chromatin Chromatid Chromosome Centromere

Chromatin vs. Chromosomes

Do All Cells Divide?? NO!! Muscles, neurons, red blood cells, white

blood cells generally DO NOT go through mitosis.

Cell Cycle Orderly sequence of

cell division INTERPHASE- Cell

grows, DNA replicates, gets ready to divide; LONG

MITOSIS (cell divides) 4 parts

Chromosome duplication

MITOSIS- Step 1 of 4 Prophase- chromosomes condense,

nuclear membrane disappears, spindle forms

MITOSIS- Step 2 of 4 Metaphase- chromosomes move to center

of the cell and attach to spindle fibers

MITOSIS- Step 3 of 4 Anaphase- Chromosome strands move

towards opposite ends

MIATOSIS- Step 4 of 4 Telophase- Chromosomes reach ends;

nuclear envelope reforms; cytoplasm divides (CYTOKINESIS)

Plant vs. Animal Cell Mitosis ANIMALS- cleavage

furrow

PLANTS- cell plate

Stages in an onion root tip

Movie Mitosis Video

Review- Mitosis Animation

Mitosis Movie!!

Cancer Out-of-control

cell reproduction TUMOR- mass

of cells Benign Malignant

Breast Cancer cells

Metastasis Most dangerous property of cancer cells is

their ability to spread beyond their original site

Detection

Detection Visual Radiation Imaging (spot glows under UV

light) Biological or chemical test (spot changes

color when exposed to a chemical)

Treatment Radiation Therapy Chemotherapy

Causes Getting older Genetics Tobacco UV radiation (sunlight) X-rays Certain chemicals

(asbestos, vinyl chloride, nickel)

Certain viruses/ bacteria (HPV, Hepatitis C, HIV)

Certain hormones (excess estrogen)

Alcohol Poor diet/ lack of

exercise

Melanoma- One Type of Skin Cancer

Breast Cancer

Lung Cancer

Prostate Cancer

Leukemia

Colon Cancer

Video The Genetics of Cancer