Unit 2 Paper

Sickle Cell Anemia

Sickle cell anemia is a disease that is caused by an allele involved in producing hemoglobin (Johnson). I find this topic interesting because of the origination of the carriers of the disease; and that in being that a carrier of the disease one is protected against malaria, a deadly parasitic disease of tropical climates (Johnson). I chose to research it further because it is interesting to me that the allele for one disease is a natural defense for another. Worldwide Malaria kills one million people yearly and where it exists it is easy to see where this trait would be an advantage (Johnson). In East Africa sickle cell anemia is common enough that almost 40% of the black population carries the trait for the disease while only 1 in 500 African Americans are born with the disease with less than 8% carrying the trait (Johnson).

            Some interesting things that I learned about the disease and trait through this research were that a sickle shaped cell only lives 10 to 20 days, unlike a normal red blood cell that can live up to 120 days (Web MD). A person born with sickle cell anemia only had a life expectancy of 14 years old in 1973(Interesting Facts about Sickle Cell). For a white person to get the sickle cell trait they must have a genetic mutation that is “1 in a trillion” because there is no genetic history of sickle cell in white people (Answers.com). The origination of sickle cell can be traced to three independent blood lines in Africa and one blood line in India about 70,000-150,000 years ago so if you have sickle cell it means you are probably a descendent of one of these blood lines (Answers.com).

            I find the sickle cell trait to be an interesting example of evolution and natural selection as well as adaptation to environment. In tropical climates where malaria is present it would be a distinct advantage to have the sickle cell trait.

Sources

Interesting Facts about Sickle Cell.<http://sickle-cell-disorder.greenwich.wikispaces.net/Interesting+Facts> accessed March 26 2013

Pain Management: Sickle Cell Disease. Web MD <http://www.webmd.com/pain-management/pain-management-sickle-cell-disease> accessed March 26 2013

Answers.com <http://wiki.answers.com/Q/Do_white_people_get_sickle_cell_disease> accessed March 26 2013

Johnson, Michael D. Human Biology Concepts and Current Issues, Sixth Edition. Chapter 19 pages 455- 456. Benjamin Cummings 2012

Part 2. Thinking About the Course

1.       The assignment or activity that I performed in this unit that I am the most proud of is the genetics/ flip a coin lab.

2.       What I now understand best about the information in this unit is how dominant and recessive traits are passed.

3.       The actions that I took to enhance learning or enjoyment of the material was to approach the material slowly and give myself time to understand it.

4.       I felt the most connected with the course while performing the virtual labs because it was a chance to actually apply the things that I was learning to a task.

5.       To help my understanding or enjoy the materials I would like to do more labs and less quizzes and tests/test preparation.