Do Now: Complete the fill in the blank work sheet on “Mitosis and Cell Division” Monday, February 11 th, 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?

Meiosis  Only occurs in “gonads” (ovaries or testes)  Only produces “germ” cells (reproductive cells)  Involves 2 divisions  1cell  2 cells  4 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.

Mitosis Interphase: chromosomes replicate Prophase: spindles and centrioles form M etaphase: chromosomes line up in the M iddle. 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. tumor cell. 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 Oncogenes Causes of Oncogenes being turned on: 2. Viruses 3. Carcinogens (Mutagens)

Normal Cell Division versus Cancer Cell Division

Risk factors for cancer 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 % 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

Diet There 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 12 th, 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 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. MITOSIS 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. MEIOSIS Cell division process: MEIOSIS

Assessment : Read textbook page Complete “Reading Check” on page 251 & 252

What are the 6 different types of Asexual Reproduction? 1.Binary Fission 2.Budding 3.Sporulation 4.Regeneration 5.Rhizomes 6.Tubers

1Binary Fission 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 adult Examples: potatoe 6. Tubers

Asexual Reproduction Sexual Reproduction Cell 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 Reproduction Let ’ s record the differences between these 2 types of reproduction: