AIM: WHAT ARE CANCER CELLS?

Do Now: Complete the fill in the blank work sheet on “Mitosis and Cell Division”

Monday, February 11th, 2013

A little review…. A gamete is a sex cell.

Sperm and ova.

• A Somatic cell is a body cell. skin cell, cardiac cell, liver cell, etc.

Haploid or Diploid?

Haploid or Diploid?

Meiosis Only occurs in “gonads” (ovaries or testes) Only produces “germ” cells (reproductive cells) Involves 2 divisions 1cell2 cells4 cells Cuts the # of chromosomes per cell in half Daughter cells receive a variety of different

genetic combinations These cells are genetically SIMILAR but NOT

genetically IDENTICAL to the Parent cells. * They share the genes from “mom and dad”

Mitosis “Body Cells”- Occurs all over the body Produces all “somatic” (non-reproductive) cells. Completed in 1 division 1 cell 2 cells maintains the same # of chromosomes per cell Daughter cells are genetically IDENTICAL to the

original. Think about it:

If you need to make more skin cells, you want them to be just like your original skin cells. The somatic cells made need to be IDENTICAL.

MitosisInterphase: chromosomes replicate

Prophase: spindles and centrioles form

Metaphase: chromosomes line up in the Middle.

Anaphase: sister chromatids start to move to opposite poles.Telophase: nuclear membrane reforms

Cytokinesis: 2 daughter cells are made, identical to the original parent cell.

Mitosis

Mitosis vs. Meiosis

• Caused by uncontrolled cell division

• Cancer cells don’t function normally, invade other tissues, monopolize nutrients, and replace normal cells

• Metastasis: the spread of cancer cells to other areas of the body

Cancer cells often spread through : lymphatic system or

bloodstream

Cancer

All cancers result from genetic changes (mutations) in the genes which regulate cell division.

Oncogenes: are genes that, when mutated or expressed at high levels, helps turn a normal cell into a tumor

cell.

What are Oncogenes?

• Tumor: solid mass of cells

1. Chromosome replication errors

Causes of Oncogenes being turned on:

2. Viruses

3. Carcinogens (Mutagens)

Normal Cell Division versus Cancer Cell Division

Risk factors for cancer:- Family History

- - you can inherit cancer genes- Aging

- - increases chance of random errors and cell damage

- Impaired Immune System- a healthy system may destroy cancer cells, so

stay healthy!- stress and disease can impair immune responses

- Exposure to Carcinogens- 85-90% of cancers are caused by

carcinogens- UV radiation

- Lifestyle - smoking, diet, etc.

Smoking• Increases risk of cancer in:

lung, throat, mouth, bladder,& liver(also a major risk factor for cardiovascular diseases )

• Chances of living to 80 in USA: non-smokers 57%; smokers 30%

• Difference in life expectancy: 15 years less for smokers

DietThere are many things that increase the risk for cancer:1. Food additives

(preservatives, pesticides, dyes and sweeteners)2. High fat diets (obesity)3. Low fiber diets and low anti-oxidant diets can increase the risk of cancer, including colon cancer.

- - fruits, grains and vegetables are high in fiber and anti-oxidants

Assessment:

Tuesday, February 12th, 2013Aim:

What are the differences

between asexual and sexual

reproduction?Do Now:

Answer this….How does a healthy cell become a cancer cell? (Use your notes from

yesterday)

Clone: A genetically identical cell

What is a clone?

How to clone an adult mammal:o Take an embryonic “stem” cell, remove the nucleus then add a nucleus from adult

o Implant new cell into female for developmentHow to clone a plant:

o Split up cells from existing plant

o Use “tissue culture” to grow complete plants from each cell

• Clones are produced naturally by mitosis

But HOW are clones produced?

• Clones can be produced by genetic engineering

Sheep

Pigs

Rat

Rabbit

Horse

Water Buffalo

Wolf

Cloning for food

• Remove the haploid nucleus from an ova & the diploid nucleus from a somatic cell

Genetically Engineered Cloning

• Insert the diploid nucleus into the donor ova

•Now we have a diploid ova

(zygote)Rapid mitosis will occur!!

What is Asexual Reproduction?

• Only one parent is needed to reproduce

asexually.

A new organism (sometimes more than one new organism) is produced from one

organism.

• In most cases: Mitosis is the only type of cell division involved

The new organism will have hereditary material identical to the hereditary material of

the parent organism.

With Asexual Reproduction…..

Offspring are genetically identical to parent

Asexual Reproduction:• Reproducing without the

interaction of 2 sexes, one parent needed.

• The make up of offspring is genetically IDENTICAL to the parent.

• Cell division process: MITOSIS

So, what is the difference between asexual and sexual

reproduction?Sexual Reproduction:• Fusion of 2 gametes

(sperm and egg).• The make up of offspring

is genetically similar, different genes though.

• Cell division process: MEIOSIS

Assessment:

Read textbook page 250-252.

Complete “Reading Check” on page 251 &

252

What are the 6 different types of Asexual Reproduction?1.Binary Fission

2.Budding3.Sporulation4.Regeneration5.Rhizomes6.Tubers

1. Binary Fission

• Organism splits into two equal halves

• Most common method of reproduction in unicellular organisms (BACTERIA)

• offspring grows from a “bud” on surface of larger parent

• will eventually break off and live independently

• occurs in: yeast, hydra (small animal) and many plants

• Budding vs. Binary Fission?

• budding divides living material unevenly

2. Budding

- spores are released in large numbers and are carried by wind or water

- can survive conditions that kill off parent

- produced by many plants and fungi (molds & mushrooms)

3. Sporulation

- ability to replace missing body parts

- occurs in all organisms to some degree

- can only produce new organisms in simpler species

4. Regeneration

- underground stems produced by plants

- As these stems grow through the soil, they produce more roots

which develop into plants

5. Rhizomes

- Modified rhizomes- Start out as a bud or eye on potatoes- Develop into root and then adultExamples: potatoe

6. Tubers

Asexual Reproductio

n

Sexual Reproductio

nCell Division

Offspring

# of parents

Genetic make-up (Heredity)

Type of Organisms to Undergo This

Type of Reproduction

Name: ______________________________ Class Period: ____ Date: ___________

Asexual Reproduction vs. Sexual ReproductionLet’s record the differences between these 2 types of reproduction: