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, 2013
Aim: 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 development
How 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: