1). Read the topic Extra cellular matrix and intercellular junctions under week -2 content ,Cell structure and functions.Watch the animation

Cancer Metastasis

Discuss the significance of intercellular junctions and extracellular matrix in cancer metastasis(spreading).

Participate individually with meaningful and original comments in the posted discussion topic. (See Academic Policies for information about plagiarism.) A minimum of 2 post(one original and one reply ) is required. Your posts should be written in your own words and should be about 100 to 150 words long.You must also post a minimum of one significant reply to classmate’s post that contribute to their learning. The reply should be a minimum of 100 words.Proper citation of sources used for your responses is expected.

Cite properly and consistently and include all sources used for your responses

POST For discussion: The ECM and the intercellular junctions both protect different parts of an organism. Once the tumor cell metastasis’ it creates the enzyme matrix metalloproteinase or MMP. The MMP then breaks off and destroys the ECM which is holding the tumor in. Once the ECM is broken, the tumor can then travel towards the blood. The MMP then breaks down the plasma membrane just like it did with the ECM. Once the plasma membrane is open, the tumor can then travel through the intercellular junction and get into the blood vessels. As soon as the tumor cell is in the blood vessel, it begins to get into the tissue which allows an easier pathway for weaker cells to get into. Overall, once the ECM and intercellular junctions are broken, it is much easier for a tumor cell to metastasis.

2). Watch the animation NON DISJUNCTION IN MEIOSIS

And refer the e text and power point for the topic Non disjunction from the chapter Cell Inheritance (WEEK -4) and discuss about nondisjunction with the help of any genetic disorder resulting from trisomy or monosomy as an example .

You can also include a Punnet square to show the cross.

POST: Nondisjunction is very fascinating in the sense that a failure for sister chromosomes to split could cause many genetic disorders like down syndrome. After reading the nondisjunction portion of the Concepts of Biology textbook, I came to find out that a failure of the of the chromosomes to split in meiosis I could cause four abnormal gametes, while a failure of the chromosomes to split in meiosis II would produce two abnormal gametes. The four abnormal gametes in the nondisjunction in meiosis I causes two gametes to have two copies of the sister chromatids, while the remaining two lack copies. If nondisjunction occurs during meiosis II, one gamete has two copies of the sister chromatids, another gamete lacks copies and the remaining two gametes have the normal number of chromosomes. Learning about nondisjunction has led me to wonder more about the correlation between age and the increase of nondisjunction as shown in figure 7.9 of the Concepts of Biology textbook

3). (1997) At a laboratory in Scotland, a sheep named Dolly has turned science fiction into science fact. The sheep is cloned, an exact replica of its mother. Born without any input whatsoever from a male. And the next step is the big one, a cloned human. It was reported that there are doctors who are willing, able and ready to take that step and turn a tiny cell into an exact, living replica of the person from whom the cell was taken. This scariest of scenarios has, of course, brought howls of outrage. As one ethicist puts it: ‘What happens to identity? What happens to personality? What happens to teenage rebellion when you’re rebelling against yourself? Children won’t just take after a parent. They will be that parent’.

The proposal to enhance the human genetic endowment by genetic cloning of eminent individuals is not warranted. Genomes can be cloned; individuals cannot. In the future, therapeutic cloning will bring enhanced possibilities for organ transplantation, nerve cells and tissue healing, and other health benefits. What is your opinion on cloning human being? Discuss why it should or shouldn’t be done considering the socio,bio and ethical factors.

Steps of DNA cloning