Endangered Species Lab

Green sea turtle from jessicamclinn

Unit 4 Paper

1.      Referring to the following list, what is your worldview? 

A.    Planetary management worldview: we are separate from and in charge of nature

B.     Stewardship worldview: we should manage earth for our benefit with ethical responsibility to be stewards

C.     Environmental wisdom worldview: we are part of nature and must engage in sustainable use

2.      Name four causes of environmental problems.

Population Growth

Unsustainable resource use

Poverty

Excluding environmental cost from market prices

3.      Think about one of the “Environmental Pioneers” described in the slideshow. If you were assigned a research paper telling the story of the career or personal life of one of these, which one would you chose as your subject and why?

I would choose Barry Commoner because I am interested in the links between science, technology, and society.

Discussion 3

Helicobacter pylori

Helicobacter pylori is a bacterium that is found in the stomach of more than 50% of the human population (Wikipedia). It was identified in 1982 so it is considered emerging, and is now believed to be the cause of some forms of chronic gastritis and gastric ulcers (Wikipedia). It is believed that the helix shape of the bacterium has evolved to penetrate the mucoid lining of the stomach, so there has been a link associated between the bacterium, stomach cancer, and certain types of ulcers (Wikipedia). While 80% of the people that carry the bacteria have no symptoms those that do experience bloating, belching, nausea, and vomiting (Davis). The rates of exposure to the bacteria and sanitation quality is also interesting to note as up to 90% of a population with poor sanitation can be affected (Davis). Today we know that up to 90% of people with ulcers also have detectible organisms in their stomach so one might think that this could contribute to a general shift in the opinion that ulcers and stomach cancer do not have a microbial cause therefore possibly reducing the occurrence of both of these things by looking at ways to treat or control cases of infection (Davis). 

Emerging infections pose a definite challenge to the future of humans because it is often hard to predict the ways in which a bacteria like H. pylori will evolve and affect us, some mutations could be harmless and others could be the cause of a devastating disease like cancer. We also know that we will be faced with the challenge of treating bacterial infections in the future due to the resistance they are forming to our antibiotics, so as this bacteria has evolved to become damaging to the lining of our stomach it might also develop resistance to our antibiotics and possibly contribute to a larger incidence of ulcers and stomach cancer.

Davis, Charles P. Helicobacter Pylori H. pylori.MedicineNet. http://www.medicinenet.com/helicobacter_pylori/article.htm> Accessed April 26, 2013.

Helicobacter pylori. Wikipedia. <http://en.wikipedia.org/wiki/Helicobacter_pylori> Accessed April 26, 2013.

Unit 3 Paper

Neanderthals

            Neanderthals or Homo neanderthalensis is a sub species of the genus Homo that we have only fossil records of (Johnson). I find this topic especially interesting because this species is closely related to modern humans. It is believed that Neanderthals diverged from H. heidelbergensis, who shares a common ancestor to modern day humans, approximately 350,000 to 400,000 years ago and are thought to have gone extinct during times of climate change roughly 30,000 years ago (Wikipedia). The Neanderthal body structure was better suited for living in colder environments and may not have adapted to climate change very well, though there are other possibilities for their extinction ranging from competition with modern humans for food to the absorption of the species through interbreeding with modern humans (Wikipedia).

            Some things that I found interesting about this topic were that Neanderthals brains were larger than modern day humans, by about 10 percent, although it was thought to be organized differently (Wikipedia). Neanderthals were also tool makers known to use stone to make axes and spears (All about creation). Neanderthals lived in complex social groups and had their own language to communicate with each other although there is not a general agreement on the nature of this language (Wikipedia). One more thing that I found interesting is that there are projects underway to sequence Neanderthal DNA with the possible hopes of artificially inseminating a human female volunteer with an egg containing the Neanderthal genome to bring the species back from extinction (New York Times).

            In conclusion I found that Neanderthals were not nearly as different from modern day humans as I had previously thought but more of a separate species brought about by a long period of genetic isolation that could be contributed to climate. They were not so much the early ape people that I had thought as much as they were a human variation physically better suited to a particular environment.  

All About  Creation. Neanderthal Man.<http://www.allaboutcreation.org/neanderthal-man-faq.htm> accessed April 14, 2013

New York Times. Scientists Plan to Rebuild Neanderthal Genome. July 20, 2006  <http://www.neanderthal-man.com/index.html> accessed April 14, 2013

Wikipedia. Neanderthal.< http://en.wikipedia.org/wiki/Neanderthal> accessed April 14, 2013

Johnson, Michael D. Human Biology Concepts and Current Issues, Sixth Edition. Chapter 22 page 523. Benjamin Cummings 2012

Part 2

1. What one assignment or activity you performed in this unit are you the most proud of?

The evolution lab because it gave my the opportunity to be creative with my answers.

2. Why did you enroll in this biology class?

To complete the Science requirement for my AGEC certificate, I live in Bagdad and this was the only online option that there was to complete my certificate requirement.

3. Did you feel prepared for this experience when you registered?

Last semester I took Environmental Biology online, that was my only previous biology course sense Jr. high School, so no I did not feel especially prepared.   

4. How was your experience different from your expectations?

This course was much more complex than I had thought possible. There is so much information to learn that it can be overwhelming at times.

5. What can I do to help you?

You do a great job explaining things in a way that I can understand but it would be of great help if you could change the exam policy to open book.

Chicken Lab

LAB

Chicken Leg Dissection

Procedure:

1.       Put on gloves and collect your tools.

2.       Thoroughly rinse and dry one chicken leg. Place it in the dissecting tray.

3.       Examine the outside skin tissue. This is the epidermis and the dimples are where feathers emerged. Using scissors and forceps. 

4.       Cut the skin and peel it away from the muscle.

5.       Notice the clear connective tissue that holds the skin to the muscles. As you peel off the skin, you may need to cut away some of this connective tissue. Work slowly and carefully with scissors and forceps until all skin is removed.

6.       Describe how the connective tissue looks and feels. What type of connective tissue is this? It looks clear but feels really strong. This epithelial tissue.  

7.       Observe, with your naked eye bundles of muscle tissue surrounding the bones. Separate the bundles of muscles by separating them out with your fingers. Begin by inserting your thumb into the muscle of the lower leg. You will need to push forcefully through the shiny lining (called fascia) over the muscle, but it will give way at the natural separations between the muscle bundles. Continue separating the muscle into bundles by forcing your thumb and fingers through the muscle until you are able to distinguish several separate bundles.

a.      Describe the arrangement of the muscle bundles. The muscle bundles were arranged layered closely together, I noticed 4 large ones and possibly one small one.

8.       The strong, shiny, white cords, called tendons, hold the muscle to the bones. Some of these tendons will pull away from the bone as you separate the muscle bundles. Use a probe, if needed, to find the tendons of the chicken leg. Using the dissection scissors, cut across the tendons at Line A (Figure 1). Observe the numerous tendons and pull the freed muscles down and away from the bone, as if you were peeling a banana. Careful you don't cut any ligaments that attach bone to bone. Look closely at the ligaments.

Examine the two bones in the lower leg. The large bone (Bone A) is the tibia. The small, toothpick-like bone (Bone B) is the fibula.

a.      What sort of connective tissue are tendons composed of? Fibrous connective tissue

9.       Remove a single muscle by cutting the tendons and peeling the muscle away from the bone.

a.      What sort of muscle tissue is represented? How do you know? Skeletal muscle, it appeared to be connected to the bone 

b.      Nerves are generally thin, threadlike white strands found between the muscle and the

nearest bone. Look for the nerve in your specimen. Did you find them? __no__

c.       What is the physical difference in the tendon of the insertion when compared to the origin? The only difference that I noticed was that the insertion appeared to be longer and thinner than the origin

10.   Remove all remaining muscle to expose the bones of the chicken leg.

a.      What is the soft material inside a bone? Bone marrow

b.      Name three specific types of cells present here. Do not break the bone; it is sharp! Osteoblasts, osteocytes, and osteoclasts

c.       Name three functions of bone. support, protection, and movement

11.   Cut onto the hinge joint by cutting into the top of the covering of the joint from the femur side. It will become apparent that you must remove the knee cap area to expose the menisci and ligaments within. Pull up on the knee cap area and cut through it with the scissors. You will have cut through the bursa, a sac that acts as a shock absorber for the knee joint. These are found in every joint.

12.   Pull the covering back and look into the inside of the joint. You will see more white bands of ligaments holding the bones together. Observe the shiny, white layer covering the ends of the bones is cartilage. It helps the bones slide smoothly when the leg bends.

13.   Bend the specimen at Joint B (Figure 1) and rotate the femur in all directions. Remove the muscle that covers Joint B by cutting parallel to the femur, upward toward the backbone. Remove pink muscle tissue until you see a shiny white sheet of ligament that covers the joint. Present is an exterior ligament that holds the femur in the hip socket

a.      What type of connective tissue composes the ligaments? dense connective tissue

Figure 2 is provided in a separate document.

b.      Label Figure 2 with the names of the joints you observed and the motion they make.

c.       On Figure 2, sketch one muscle origin (the name of the bone indicates the insertion) and one muscle insertion you can see in the leg.

14.   Dispose of materials as directed.  Make sure to wash your hands, tools, and work station with plenty of soap and water.

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.

Discussion 2

The Value of Reproductive Cloning

Reproductive cloning means to create a duplicate of another organism genetically.  The most common method used to create a clone of an organism is somatic cell nuclear transfer or SCNT, more than eighteen cloned mammals have been created this way though as far as we know none of these have been humans (Center for Genetics and society). In this process the nucleus is removed from a fertilized egg and a somatic cell from the DNA donor is then inserted (Johnson).  This fairly new science has brought about its own ethical debate mostly revolving around what it is to be human and at what point in development should we be recognized as such.

The advocates of reproductive cloning insist that it is a viable option for couples that would like to have a genetically related child but are unable to produce one naturally or with the help of fertility treatments. There is also the possibility that a parent who has lost a child could benefit from creating a clone or a genetic replacement of the deceased child. Both of these arguments are highly controversial and have been met with strong opposition especially from fundamental religious organizations. There are more practical possibilities though for reproductive cloning that include helping bring back a specific animal species from the verge of extinction to possibly bringing back an animal that has been long gone like the woolly mammoth(Library Index). There is also the idea that if your favorite pet dies you could create a genetic replacement as well.

The opponents of reproductive cloning argue that it is unethical because a fertilized egg has to be essentially destroyed in order to create a suitable environment for the DNA to be cloned. It is also not hard to see that a human cloned to replace one that has died by essence devalues their existence. Then there is the safety involved of the person being created as there is a high failure rate in animal cloning and a greater chance for cellular anomalies like cancer and disease (Center for Genetics and society).  So at what point they might ask are we going to draw a line before the science becomes an inhumane experimentation on human beings?

My opinion on the topic of the value of reproductive cloning is probably a bit more on the liberal side than the average person as I do not see a fertilized egg as much more than a group of cells. If it is potentially possible to clone someone like Albert Einstein than wouldn't we be doing the human race a favor? If there was not such a health risk for the cloned individual I don’t think that I would oppose human cloning. I just don’t see it becoming something that would be easily accessible to most people, you would most likely have to invest a great deal of money into having a clone created so I am not sure that it would be abused in the dramatic ways that can be imagined. But it would not be unwise to pass strict regulations protecting the basic human rights of cloned individuals.

Works Cited

“About Reproductive Cloning.” Center for Genetics and society.<http://www.geneticsandsociety.org/section.php?id=16> . Accessed March 1, 2013.

“Cloning-Reproductive Cloning.”Library Indax.<a href="http://www.libraryindex.com/pages/2263/Cloning-REPRODUCTIVE-CLONING.html">Cloning - Reproductive Cloning</a>. Accessed March 1, 2013.

Johnson, Michael D. Human Biology Concepts and Current Issues, Sixth Edition. Chapter 17 page 421. Benjamin Cummings 2012.