Tuesday, April 30, 2013
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.
Friday, April 26, 2013
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.
Sunday, April 14, 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.
Saturday, April 13, 2013
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.
Wednesday, March 27, 2013
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.
Sunday, March 3, 2013
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.
Monday, February 18, 2013
Unit 1 Paper
Part 1. My Interest in an Aspect of Unit Content
ATP
Adenosine triphosphate
or ATP is a universal source of energy for cells. The energy is derived from the
breakdown, or hydrolysis of the nucleotide, in the bonds between the phosphate
groups. Broken down, ATP produces ADP or adenosine diphosphate, and Pi an
inorganic phosphate group, as well as energy that can be utilized for cellular
functions (Michael D. Johnson). This process can also be reversed to recycle
the ADP into ATP by using energy from the food that we eat to reattach the
phosphate group to ADP (Michael D. Johnson).
Each molecule of
ATP is recycled somewhere between 500 to 750 times just in one day in the human
body (Adenosine triphosphate).
It is able to do this because the body keeps an uneven ratio of ATP to ADP; approximately a 1000 to 1 ratio. This uneven ratio contributes to the amount
of free energy that can be harnessed and used by the living system (Adenosine triphosphate). There are three main uses of ATP that include; the transport of
organic substances through a cell membrane, the synthesis of chemical
compounds such as protein, and the energy supply for muscle movement (Maria
I. Martos).
To conclude; ATP is a very valuable source of renewable energy for living systems. It facilitates almost every aspect of cellular function that requires energy as a coenzyme. It is often referred to as the “molecular unit of currency” part of the energy transfer process inside of a cell (Adenosine triphosphate). A title that is well deserved being as versatile and useful as ATP is to a living system.
To conclude; ATP is a very valuable source of renewable energy for living systems. It facilitates almost every aspect of cellular function that requires energy as a coenzyme. It is often referred to as the “molecular unit of currency” part of the energy transfer process inside of a cell (Adenosine triphosphate). A title that is well deserved being as versatile and useful as ATP is to a living system.
Sources
Adenosine triphosphate. Wikipedia. http://en.wikipedia.org/wiki/Adenosine_triphosphate
Accessed 2/18/13
Johnson, Michael D. Human Biology Concepts and Current Issues, Sixth
Edition. Chapter 2.1 page 46. Benjamin Cummings 2012
Martos, Maria I. Adenosine Triphosphate The Necessary
Fuel for All Body Cells An Overview. http://www.sagewoodwellness.com/Doc0002.htm Accessed 2/18/13
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 What Molecule/ DNA Extraction Lab because even though
it was confusing for me, I did end up completing it correctly.
2.
What I now understand best about the information in this
unit is how the cell uses ATP for energy.
3.
The actions that I took to enhance learning or enjoyment
of the material was mostly not expecting
myself to understand the material the
first time I read it and giving myself time “get it” without getting frustrated.
4.
I felt the most connected with the course only after
completing each assignment or quiz, each completed part seems to add a piece to
the puzzle. I definitely felt the most distanced from the course upon the
introduction of each new concept.
5.
To help my understanding or enjoy the materials my
instructor could look into what is causing the buzzing noise in the background
of the video presentations, it drives me crazy.
Friday, February 15, 2013
Lab; Milk, Juice, Carrot
Milk: Record your hypothesis, observations,
explanation, and factors here.
Hypothesis: I thought that after 3 days the milk would develop a very
bad smell because it was not refrigerated.
Observations: After 3 days upon inspection of the milk I noticed no
odor.
Change: After 3 days there were clumps in the milk.
Factors: I think I could call what I made cottage cheese.
Juice: Write your observations and
explanation here.
Observations: Cup 1 (room temperature) seemed to diffuse the grape
juice at a moderate rate, cup 2 (boiling water) diffused the grape juice faster
than the room temperature water, cup 3 (ice water) diffused the grape juice
slower than the room temperature water. I think that this was because the
warmer the water is the more movement there is going on in it; whereas, the
colder the water gets there is less movement until it becomes ice (solid).
Carrot:
Record your hypothesis, tightness of string and texture observations and
measurements, and what type of water caused shrinkage or expansion here.
Hypothesis: I thought that after 24
hours the carrot in the salt water would shrink while the carrot in the fresh
water would expand. I believed this would happen because this was the way that
it would work with a eukaratic cell in hypertonic and hypotonic solutions.
Observations: The tightness of the
strings of both carrots was mildly tighter after being submerged for 24 hours. Though
the carrot placed in the fresh water was 1/8 inch wider but the same length and
the carrot placed in the salt water was 1/8 inch longer but the same width.
This would imply that the string was tighter around the carrot placed in the
fresh water but if it was it was not visibly noticeable.
Initial length and width of
carrot pieces:
Piece 1: The carrot piece placed in the fresh water was
2 ¾ inches long and 1 inch wide.
Piece 2: The carrot piece placed in the salt water was 2
¾ inches long and 1 inch wide.
After-experiment length and width
of carrot pieces:
Piece 1: After 24 hours the carrot piece placed in
the fresh water was 2 ¾ inches long and 1 1/8 inch wide.
Piece 2: After
24 hours the carrot piece placed in the salt water was 2 7/8 inches long and 1
inch wide.
The beginning |
After measurements of carrot in salt water |
Thursday, January 24, 2013
The Autism and Vaccine Controversy
For years there has been a debate as to whether or not autism can be caused by childhood vaccines. Many parents have in fact opted to not have their
children receive vaccines as a result of this argument, and we are again seeing the rise of serious illnesses that at one point had nearly vanished
from America.
One
viewpoint is that the controversy between autism spectrum disorder and vaccines
today is due to a correlation between the MMR vaccine and autism. The idea is
that diseases like measles by nature attack the bowels and that autism is
triggered by an inflammatory bowel condition (Body Ecology). Although this has
not been proven to be true, the correlation for some people is enough to
persuade them. Advocates of this idea argue that there have been issues with
vaccines causing various types of illness for many years, and that today 1 in
every 150 children is diagnosed with autism as compared to less than twenty years
ago when the number was 1 in 10,000 (Liu,Caleb).
Those
who oppose the idea that immunizations are the cause of autism argue that a child injured by a vaccination may have had
underlying immune or metabolic problems that were made apparent by the vaccine.
In these children, receiving a vaccine could be a nonspecific trigger
responsible for the discovery of their underlying issue (Harris, Gardiner). They would also argue that the benefits of
childhood vaccinations outweigh the risks that there could be a correlation,
because the diseases that are being prevented by vaccination are far more
dangerous than the chance of it causing autism. They also raise awareness that
improvements in the screening process for autism could be a likely contributing
factor to the increase in the diagnosis of the disease.
In
my opinion people are naive not to have their children vaccinated. They have
not lived through an epidemic of the proportions of polio or have seen the
devastation that can be caused by an illness whose vaccine was unavailable. I personally know a teenager whose life was severely altered by
contracting meningitis when he was little; he has the mental capacity of a 5
year old and will never live independently. Today there is a vaccine for this,
but then there was not.
Despite
scientific studies that have concluded that autism is not caused by the MMR
vaccine (CDC), the debate will probably continue to surface until science is
able to come up with a better explanation. One side is convinced that a vaccine
is to blame and the other is just as certain that it is not. It is my
conclusion that there needs to be more research done in the area of autism to
find the actual cause of the disease so that the parents that are skeptical about
vaccines can put their fears to rest. It is apparent that just doing studies
proving that vaccines are not the cause of the disease is not enough. More research would be a
win-win situation. The sooner we can find a cause the closer we are to finding
a cure; how ironic would it be if one day we could even vaccinate against
autism.
Body Ecology. Autism and Vaccines: The Truth Behind the
Controversy.
Liu, Caleb.Increase
in Autism - Why Have So Many Children Been Diagnosed With Autism Since the
1990's?
Harris, Gardiner.Vaccine Cleared Again
as Autism Culprit
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