Knowledge Base Article
Article ID: 27138 [Last Updated10/18/2005 8:43:19 AM]
Summary:
Two example biology lab reports
Article:
Experiment 1.2
Lab Report
The purpose of this experiment was to learn the proper use of a microscope and to observe thread and my own cheek cells under the microscope.
Thread:
At low power, you could see some of the fine structure of the thread.
(drawing of the thread at 40x)
At medium power, the center of the thread was completely black. However, the fibers at the edge of the thread were easy to see.
(drawing of the thread at 100x)
At high power, most of the thread was black. However, the edges were very "hairy."
(drawing of the thread at 400x)
Cheek cells:
At low power, the cells looked like tiny circles.
(drawing of the cells at 40x)
At medium power, the nucleus was visible as was the membrane of the cell.
(drawing of the cells at 100x)
At high power, we saw the nucleus and cell membrane even more clearly.
(drawing of the cells at 400x)
Summary:
In this experiment, I learned about the individual parts of the microscope and its proper use. Then, to get some practical experience, I looked at thread under the microscope. Even though it was hard to see a lot of detail at high magnification, I could see that the thread was made up of individual fibers.
I then scraped the inside of my cheek with a cotton swab and rubbed the swab on the microscope slide. This transferred cheek cells from my mouth to the slide. To make the cells easier to see, I added a methylene blue stain. It took a while for me to find them, but eventually I did. They were oval-shaped with a prominent nucleus in the center. The stain made the nucleus easy to see. The cell membrane was also easy to see.
Experiment 2.2
Lab Report
The purpose of this experiment was to collect live specimens of various microoganisms that feed on different things. I was looking specifically
for bacteria, stentors, algae, diatoms, protococcus, vorticella, paramecium, amoeba, euglena, chlamydomonas, and volvox.
(The lab asks the student to draw the microorganisms he or she sees. Those drawings are here. They are the data from the experiment.)
Summary:
I filled four jars halfway full of pond water from a pond in Chester
County, PA. To one jar I added hay, to another egg yolk, another white
rice, and the last rich soil. After four days, I found paramecia and volvox in the jar that had hay in it.
The jar with soil had amoebae and bacteria. In the egg yolk mixture I discovered bacteria and algae.
I found nothing in the rice mixture after close examination.
From this experiment, I learned to identify microorganisms, and I saw that
although the water came from the same pond, the food in which the
microorganisms were cultured really makes a difference on what grows well
in the samples.