- To explain how DNA is transmitted to the next generation via meiosis followed by fertilization
- To understand how meiosis and crossing over leads to increased genetic diversity, which is necessary for evolution
Investigation 7: Cell division- Mitosis and Meiosis
Review Part I: modeling mitosis-
Part II: stay tuned-
Loss of cell cycle control in cancer cells
Discuss your answers for review for part i and Prelab for Part 3 (pg 90)
A cancer tumor forms in a bed of healthy cells. The animation goes on to show how the tumor recruits blood vessels and how metastasis occurs.
Cancer occurs when a single cell acquires the ability to reproduce aggressively and to invade other tissues. This rebellious cell shuns its normal role, instead multiplying and ultimately colonizing areas of the body where it doesn't belong. Left unchecked, this anarchy destroys the cellular society. It interferes with the body's normal function, destroys organs, and eventually kills the organism.
More About Using p53 To Fight Cancer
A problem with most current cancer treaments, such as radiation or chemotherapy, is that they harm both cancerous and normal cells.
A new experimental method takes advantage of the fact that many cancer cells have a mutant form of the protein p53. In the treatment, all cells are exposed to a genetically modified cold virus that infects both cancerous and normal cells. However as the viral DNA tries to replicate in the nucleus of a normal cell it is suppressed by the presence of healthy p53 protein. In the cancer cell however, p53 is mutant and inactive, and therefore the cell cannot defend itself from the invading viral DNA, which ultimately kills it.
Background on Using p53 to Fight Cancer
Knowing the genetic path that a particular cancer follows could someday help physicians better treat individual patients. By determining the genetic defects responsible for a specific cancer, physicians might be able to select the therapy that will be most effective at eliminating that cancer. Furthermore, each cancer-causing gene that researchers identify can serve as a target for the development of more specific therapies that will wipe out cancer cells while leaving healthy cells unharmed.
Develop a hypothesis as to how the chromosomes of a cancer cell might appear in comparison to a normal cell and how those differences are related to behavior of the cancer cell.
- -observe karyotypes of normal and HeLa cells
HW: from the video content below or from an on-line search answer the 10 questions on page 91 regarding the case study of Henrietta Lacks
great video on HeLa cells- Cold Spring Harbor - EC: 10 pts. outline of main points of video.
Case II: Philadelphia Chromosomes
Please answer the 5 questions about the leukemia cell karyotype on page 92http://www.hhmi.org/biointeractive/media/DNAi_cml_gleevec-lg.mov
Part 4: Modeling Meiosis
Answer 4 pre-activity questions
Use chromosome simulation kit to simulate process of meiosis.
Answer 12 questions on pages 92 and 93 about meiosis.
Be able to compare and contrast the processes of mitosis and meiosis.- (diagram and helpful animation videos below)
Part 5-stay tuned until we get the Sordaria cultures.
That's all for Investigation 7