October 29

Today, first we handed in our graphs and conclusions for the online bacteria lab, and Mr.Finley annonced we would be starting our lab reports for our bacteria petri dishes soon. He showed us a new insrument; the stereoscope. It is similar to a microscope, but it has 2 eyeholes. Compared to a microscope, it is different because it allows us to look at bigger things than a microscope, close up. Although we cannot see individual bacteria with it (we can only see bacteria colonies), Mr. Finley said we would use it to look at our petri dishes. One of the circular blobs in our petri dishes would be a bacteria colony.
Next, Mr. Finley showed us how to use a stereoscope. First, adjust the eyeholes so you can see into the stereoscope. Then, adjust the magnification so the object is seeable. Next, adjust the focus knob to get the object in focus. Lastly, hit the red button to turn on the light. Also, when you carry it, hold it by the base and the neck.
Next, we observed our petri dishes under the microscope. First, we looked at a bacteria colony, and it showed up as a huge red circle that took up nearly everything we could see through the stereoscope. Then we looked at another bacteria colony, and it appeared to be a large pancake with a large lump of butter on top. The mold looked like a large forest of white hair. Once we finished looking at the petri dish, we started typing our conclusions for the lab report.


Here is some vocab we defined in class today:
Stereoscope-a microscope with two eyeholes, used to look at bigger things than a microscope
Microscopic-Something you cannot see with your eyes
Macroscopic-Big
Colony-A group of organisms all in one place

Something that may be tricky is being able to see through a stereoscope. The reason many people screw it up is that they don't have the eyeholes in the right place. A good way to adjust them properly is to put your eyes up against them and slowly move the eyepieces in or out. Eventually you should be able to see through them, becaus you will have gone throught the entire range of viewing angles.

Here is a link to a lab report rubric from another school disttrict
http://sciencebass.tum.abss.k12.nc.us/modules/locker/files/get_group_file.phtml?fid=2134278&gid=326235&sessionid=200b7bc2e1972dfd5662c6a6ea2db723

Here's another link:

http://sites.google.com/site/grahamscience/new_lab_rubric.doc

LG Period 8