Life exists almost every where on this planet and if we are to attempt to comprehend what life is in all of its magnificence we must look at its simplest forms. Even a cell, the smallest form of life known is extremely complex. All life begins as a single cell. I can not begin to understand the depth of what it takes for one cell to multiply and change until we become conscious of ourselves. There are two types of cell division, Meiosis and Mitosis. Meiosis is where a cell splits and becomes four different cells. Mitosis is the process that allows a cell to split into two identical cells. This happens by having all of the DNA replicate before the cell splits so each has all of the original DNA. My lab shows mitosis in cell reproduction, because I do not have a microscope powerful enough to see the actual process within the nucleus I can not observe the chromosomes actually duplicate and separate. It is powerful enough to allow me to see cells splitting and I can observe the population growth without the aid of tools or instruments. First I began by starting the yeast culture in a bowl. I then removed a sample to observe it using a microscope. All throughout I measured the thickness of the yeast population. These observations combined show that through mitosis cells reproduce.
The challenge that faces me is how can I demonstrate mitosis or cell reproduction. The reason I have to do this is so that I can actually observe the process as it occurs and not just read or do work sheets about it. Unlike our former labs now we are not in absolute control of the lab. Density is a constant and properties of light are facts that can be stated in words. Life even on the smallest scale, cells, can be unpredictable and uncontrollable.
If I put yeast in warm water with sugar and flour then the culture will grow because the cells will reproduce through mitosis.
1. Pour 2.5 cups warm water into bowl.
2. Add 3 table spoons of sugar into the water and stir.
3. Add just enough yeast to cover the surface of the water.
6. Every 5 minutes measure the thickness of the layer of yeast up to 1 hour.
7. After 15 minutes add .5 tablespoon sugar and stir again.
8. After another 15 minutes stir and take a small sample of the yeast population.
9. Place the sample on a slide add iodine and place cover slip over sample.
10. Observe under a microscope on all three powers.
The thickness of the layer of yeast after time.
051015202530354045505560The data set that I studied should resemble an exponential model but because of time constraints I only observed the very beginning of its growth. If I gave the population more time and I continued to add food it would probably have kept reproducing until constraints like space and/or its waste (alcohol and more) began to slow its growth.
When I viewed the yeast under the microscope, the cells appeared average in size relative to the cells we looked for the other cell lab. I do not think I used enough iodine or I should have used a different die because I had a hard time seeing the nucleus. I did see the cells divide but it wasn’t in great detail. I couldn’t see the chromosomes but I did see the cell divide and blurry unknowns that was probably the nucleus and perhaps other organelles. When I looked at the sample on the lowest power I could easily see the population grow, even though individual cells could not be seen the sample seen never stopped moving.
The main reason I conducted this lab was to show that mitosis is a process that in which cells reproduce. Personally I think that this is the most helpful lab we have done as of yet. The other labs were mainly about mathematics or rules. These concrete ideas are just as easily learned through lectures and work. But this lab deals with living things. In order to learn about concepts that can not be worked out on a calculator or memorized, a person must experience it. Unless we actually see these cell function occurring most people could not make the leap from a picture on a paper to what it actually must be like.
I am doing this at home because I was not at school, therefor I do not know if the labs are similar to mine, (or mine to theirs). I designed the lab this way because I love to cook and eat. When I make bread yeast is used and I already knew they reproduced and I knew generally how they did it, now I just know that it is called mitosis and involves many molecules with odd names.
My lab showed that cells reproduce and that they do so by mitosis. Both watching the culture grow larger over time and seeing the cells through the microscope displayed the fact that cells reproduce. Looking through the microscope shows that cells split into two identical cells. By focusing in on a few cells on the highest power and being patient a cell slowly split into two cells. I moved the slide and again after remaining vigilant I saw cells split again. Inside the nucleus the chromosomes duplicated and were pulled to the centriols, all I could see was a dark spot grow oblong thin split.
If I put yeast in warm water with sugar then the culture will grow because the cells will reproduce through mitosis. My hypothesis was correct. The culture grew and nearly doubled over an hour, and when I used the microscope to watch the cells I saw them go through mitosis.
Most of the problems I encountered were easily solved because I was at home, one that I couldn’t solve is that I ran out of iodine after a few mess-ups and it may not have been the right dye to use anyway. When I put flour in the first time so it could survive, but longer the flour stopped me from seeing the cells on the slide. All I had to do was rinse out the bowl and try again, excluding flour. Other small annoyances were not having the materials until the day before this is due and spilling. A potential problem for others was a blessing for me, I got to work alone, and I didn’t have anyone to slow me down, goof off or attempt to contribute when their help is not wanted. The only inconvenience stemming from this was that there was no-body to take my partner’s place in pointing out my rare careless mistake and/or saying something on topic and intelligent once in a while.
There are many things I would improve upon, first and for-most is better equipment, namely the microscope. If the microscope was more powerful I could have gotten the full affect of seeing what took place inside of the nucleus. A different place I could improve upon is observing the culture over the span of a few days, this wouldn’t exactly improve the, mitosis part of the lab but it would be nice if I could have seen the entire population model instead of just the first segment. My lab met all of the requirements including being on time therefor I label it a success.
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