I am most proud of my compendium reviews. I feel that I spend a lot of time on those and use the internet as a resource to supplement the class material in a way that makes the learning interesting and the information easy to recall. I am also proud of my quiz grades. I’ve taken the time to review the material and this is reflected in them. Lastly, I’m proud of the fetal development lab. I learned a lot when picking and choosing the events I felt to be most relevant during the development process.

2. What two aspects of my submitted assignments do I believe could have used some improvement? I could have spent more time on the last lab assignment. We lost electricity for several days this past week and I waited until the last minute to finish that one. I would have liked to use personal pictures instead of ones online, but was under a time constraint to get it done. Also, I would have spent more times with the weblinks this unit. I didn’t focus as much on them as I had in other units.

3. What do I believe my overall grade should be for this unit? I feel that I should get an A in this unit. All of my work is complete and on time, as per the directions.

4. How could I perform better in the next unit? Now this makes me happy. This is the last unit.

REGARDING THE UNIT (adapted from Stephen Brookfield, University of St. Thomas “Critical Incident Questionnaire”)
At what moment during this unit did you feel most engaged with the course? I felt most engaged during the Fetal Development Lab. A lot of my friends are going through pregnancy so it was the assignment of the most interest to me.

At what moment unit did you feel most distanced from the course? When our power went out this weekend from a monsoon–I couldn’t access the coursework and had luckily completed most of it early.

What action that anyone (teacher or student) took during this unit that find most affirming and helpful? I was pretty much on my own in this unit.

What action that anyone (teacher or student) took during this unit did you find most puzzling or confusing? Again, I was pretty much on my own here.

What about this unit surprised you the most? (This could be something about your own reactions to the course, something that someone did, or anything else that occurs to you.) I was surprised about how much of the information I already knew. I’d taken one biology course in high school, and much of this information was covered then. The unit was a good review, though I’d expected more new information.

Physical Landscape:

The Water Cycle: The reservoir of the water cycle is freshwater that evaporates from the ocean. Water that falls on land enters the ground, surface waters, or aquifiers and evaporates again. All water returns to the ocean.

The Carbon Cycle

The reservoirs of the carbon cycle are organic matter. (forests and dead animals for fossil fuels), limestone, and the ocean. The exchange pool is the atmosphere. Photosynthesis removes carbon dioxide from the atmosphere. Respiration and conduction add carbon dioxide to the atmosphere.

The Greenhouse Effect

The Greenhouse Effect is the rise in temperature that the Earth experiences because of certain gases in the atmosphere that trap energy from the sun. The gases are referred to as greenhouse gases because they warm the world. These gases include carbon dioxide, water vapor, methane, etc).

Biological Landscape: Domestication

The basis for our relationship with domesticated species includes the following:

-Food and Agriculture (food crops and animals)
-Transportation (animals)
-Care and Protection (pets)

Wikipedia provides a great, in-depth look at the history of domestication.

In the third world island nation of Vanuatu for instance population growth may not have that much effect on energy use. Typically, there is no electricity, no vehicles, no running water. When a family increases in size they adapt to the addition by planting extra crops. Bathing is done in streams, the ocean, or in rain. Composting toilets are used.

In America, however, an addition to the family generally means a larger (less full efficient) vehicle and one more person to use an abundance of unnecessary electricity and water resource. “A typical U.S. child will consume the same resources as 30 children in India and 300 children in Ethiopia. A typical U.S. resident consumes energy as if they were a 30,000 kg primate”.

We should stop encouraging economic development in “under-developed” countries. The fact is, we are over-developed and enabling an abuse of world resources. America would do well to take others into consideration for once: un-develop and waste less.

These images show a human population simulation. The time frame for this simulation extends to the year 2050. The first simulation shows the world population versus that of Yemen. The second simulation shows the world population versus that of the United States.

1. My high fertility rate country was Yemen. The fertility rate for this country is 7.3 children.

2. My low fertility country was the United States. The fertility rate for this country is 2 children.

3. High fertility rate results in a high number of young people in a population. In Yemen for instance, the fertility rate is 7.3. If each family has seven children, there is a good possibility that many of those children are young in age. Also, the life expectancy is not that high in Yemen (only to the average age of 50). The pyramid shape results because there are many more young people than old people. As far as future population growth–there will be a substancial increase in population. (If each of those 7 children reproduce even one child there will be a dramatic increase in population).

4. Low fertility rate leads to a lot of middle aged people. If the fertility rate is low, people are not reproducing at a high level of frequency so the youngest demographic will taper off. Also, the oldest generation will be smaller in number because of natural death. The result of the two will be a more in-between population demographic.

5.

Middle Aged/Older: quiet, reserved, calm, organized, efficient, scheduled, maintained, orderly, strict, understimulated

Children: loud, chaotic, overstimulated, reckless, unorganized, unscheduled, disorder, free-spirited, mess, fun

Human Life Cycle

Meiosis

How an Organism is Started

Fetal Development and Birth

Why We Develop and Age

The life cycle of higher organisms requires two types of cell division.

Mitosis: growth and repair of tissues

Meiosis: gamete production

Meiosis happens in the ovaries for females. One egg per month bursts from the wall of the ovary to be taken up into the Fallopian tube. This is Phase I. Phase II occurs if the egg is fertilized.

For males, meiosis is undergone constantly by sperm in the walls of tubules.

The image to the left illustrates the human life cycle. A detailed explanation is as follows: “This figure illustrates the human life cycle. Adults produce gametes by meiosis, and each gamete contains only one-half the number of chromosomes found in the somatic cells of the parent. Parental cells (containing 46 chromosomes) are called diploid cells, and are abbreviated as “2n.” The gametes (containing 23 chromosomes) are called haploid cells, and are abbreviated as “n.” When a haploid ovum and a haploid sperm unite through fertilization (also termed syngamy), a diploid zygote is produced. The life cycle describes how diploid (2n) individuals produce haploid (n) gametes, which then unite to form a new diploid (2n) zygote.

This alternation of meiosis and fertilization is found in the sexual life cycles of all sexually reproducing organisms, but its timing can differ considerably, depending on the organism. The human life cycle typifies the most common life cycle found in animals, where the gametes are the only haploid cells. They combine to form a zygote, which divides by mitosis (cell reproduction; discussed in more detail in tutorial 25) and grows to form a new individual.

In a second type of life cycle, as seen in most fungi and some protists (unicellular eukaryotes and their somewhat simple multicellular relatives), the diploid zygote produces haploid cells by meiosis; these develop into free-living, haploid, multicellular organisms. The haploid organisms then produce modified gametes by mitosis (they are already haploid, therefore, they cannot undergo meiosis), and these gametes unite to form diploid zygotes. Some plants and algae exhibit a third type of life cycle, termed alternation of generations. This life cycle contains both haploid and diploid, free-living, multicellular stages. The diploid multicellular stage, the sporophyte, produces spores by meiosis, which develop into a multicellular haploid stage, the gametophyte. The gametophyte produces gametes by mitosis, and these unite to form a new sporophyte. Although these three types of life cycles differ in the timing of fertilization and meiosis, they all produce genetic variation in their offspring “.

The image to the right is an overview of the process of meiosis.

Another really informative site with great illustrations on meiosis can be found at this link.

An organism is “started” when the sperm nucleus enters the egg and bonds with the egg nucleus.

The image to the left shows both the sperm and the egg. If an egg and a sperm meet in the Fallopian tube there is a good chance that one sperm will join with the egg, resulting in fertilization.

Fetal Development and Birth At the end of the embryonic period, all organ systems are in place and there is a mature and functioning placenta.

Fetal development extends from the third through the nine months. During the third and fourth months the skeleton is becoming ossified. (bone formation is occurring). The sex of the fetus also becomes evident. The fetus continues to grow and gain weight until it reaches nine months/birth.

During the first stage of birth the cervix dilates. Stage two takes place as the child is born. Stage three is the expelling of the afterbirth. Development after birth includes infancy, childhood, adolescence, and adulthood.

Aging may have a genetic basis and may be due to changes that affect the whole body. (the decline of the hormonal system for example). Aging can also be due to diet and exercise. Deterioration of organ systems can possibly be prevented (in part) by good health habits.

I began by forming the bone structure. First is detail of the ball and socket joint that connects the pectoral (shoulder) girdle and the upper limb.

The large bone at the top of the arm is the humerus. This is joined to the two lower bones in the arm: the radius and the ulna. (The humerus is connected to the ulna with a hinge joint).

Next is detail of the arm at rest.

The muscles here are represented by the pink playdough.
Tendons are represented by the blue. Tendons enable the muscle to move the bone.

In the first image below, the bicep muscle is relaxed, while the tricep muscle is contracted.

In the second image the opposite is true. (This is because the bicep and the tricep muscles are antagonistic–meaning that they work in opposition).

Prior to the change in arm position, a neuron would carry a message to the muscle, signaling the muscle to contract. The image below shows a neuron signaling the bicep to contract.

A neuron is represented by orange colored playdough. The signal being sent by the neuron is also known as a nerve impulse or action potential. The Schwann cell (and myelin sheath) are represented by the smallest blue pieces of playdough within the orange (*not to be confused with the blue tendons–I ran out of colors!).

Ugh, I can not get these pictures to format. From left to right they are A, B, and C.

A

D

Image A shows a motor neuron. Again, Schwann cells are represented by blue. Neurotransmitters are located at the end of the strands in axon terminals. These send messages between the neurons.

Image B shows sarcomeres that are contracted. Image C shows sarcomeres that are relaxed. Both images represent the sliding filament process. Actin is represented by the pink, while myosin is represented by the orange. During this process the sarcomere shortens and actin filaments slide past the myosin filaments.

Image D shows action potential. The nerve impulse passes/is sent rapidly from one section to another.

Thus, the entire systems works together to enable movement. Movement begins as the central nervous system transmits a message via neurons. Nerve impulses then initiate the action. In conclusion, the process of initiating human movement likely simulates the process of initiating movement of other organisms. (image)

(Also, an informative page on the sliding-filament theory of muscle action can be found here).

*source: Mader, Sylvia. Human Biology, tenth edition.

Exercise has a substancial number of benefits. Studies have shown a correlation between exercise and the improvement of cardiorespiratory endurance. Exercise helps prevent weight gain because muscles metabolize faster than other tissues. A favorable change in body composition is often coupled with exercise. Exercise seems to prevent certain kinds of cancer as well as depression. So why aren’t we exercising? (she types after having spent multiple hours herself sitting in front of a computer desk).

For many, exercising is an inconvenience. Sure, some of us are within walking distance to the grocery store. With the increase of gas prices it would be sensible to walk to pick up dinner ingredients. Though in a society where we are stretched for time, one likely wouldn’t have time to walk to the store and make dinner. One or the other. Most choose to drive to the store to save time. The fast-paced environment we are living in has a lot to do with our daily activities.

Also, safety and security concerns may limit a person’s amount of exercise. As a woman, there are certain areas that I personally would not be comfortable working out in. Gym memberships are expensive, so while an alternative to outside exercise–it is not a practical alternative for everyone. Advances in technology have both propelled and inhibited us. Physical exercise is being replaced with mental exercise in the form of video games or television entertainment. Opportunities such as online classes encourage a degree of physical inactivity.

Lack of time, safety, and money seem to be major factors as to why people do not exercise. Taking the initiative to start community wide exercise programs would give some the incentive and support they need to begin an exercise program individually or within their family. As a society, we have gotten into a habit of increasing our mental activity and decreasing our physical activity. As a whole, we need to find time to balance the two.

These two pictures were taken during the lab. The image on the left shows myself about to make a fist around the pencil sharpener. The image to the right is preparation for the change in temperature testing.

Effect of Temperature on Muscle Action:

Number of fists in 20 seconds
normal temp. = 21 fists
after ice = 17 (very uncomfortable!) fists

Number of fists in 20 seconds *with pencil sharpener
normal temp= 15 fists
after ice = 12 fists

Number of fists per trial
1. 16
2. 16
3. 15
4. 15
5. 15
6. 16
7. 13
8. 12
9. 13
10.13

Analysis of Data:
1. What are the three changes you observed in a muscle while it is working (contracted)? When an activity is repeated the muscle is tired and can not perform the activity at its initial rate of speed. The muscle is tight/hardened when it it working. Also, the muscle appears larger when it is flexed.

2. What effect did the cold temperature have on the action of your hand muscles? Explain. The cold was very uncomfortable for my hand muscles–I had a hard time even keeping them in the ice. The change in temperature made it more difficult to open and close my hand. It was very constricting to the muscle.

3. (graph eliminated)

4.What effect did fatigue have on the action of your hand muscles? Explain. Fatigue slowed the action of the hand muscles. As I progressed through the trials, the longer I had been doing the activity, the lower the number of fists I was able to make.

It seem the contraction of the hand muscle was an attempt to warm the hand. The muscles were contracted in order to break down ATP to regulate the sudden change in temperature. Also, due to the nature of the exercise, the muscle did not have time to relax between fists for the final testing. Calcium was not returned to the muscle and therefore the hand muscles wanted to remain contracted and the action of making a fist was slowed down.