science prac help?

Question

well in class we were doing this experiment when we get union skins under the microscope we then put methylene on them and put cover slips on that and blah blah blah anyways there was a couple of questions i didnt understand 1 was "why did the feild of view decrease?" another was"why did you see less in high power on the magnifying scope" and wat was the use of stain (wat is stain????:S) plz help me:( i dont want to fail:P


p.s my science teacher sux at explaing things...

Answer 1

The field of view decreased because you increased the magnification. The field of view is the amount of area that you can see. It's like those diagrams of close-ups you've seen, where they have a big picture, and then a little circle which is blown up? It's the same reason; you're seeing it in higher magnification, but if you have the same area to see it, then you see less in terms of area.

Stains are important in studying living things because most structures and molecules in teh cell is completely transparent; so if you don't stain it, then you won't see anything at all. What a stain does is it bonds with certain structures in the cell and makes them visible. For instance, the common iodine stain used in middle school/high school microscopy labs lets you see membranes, and htus the nucleus.

I'm not sure what you mean by methylene; chemically one methylene makes no sense, because an -ene is a hydrocarbon with a double bond, but methyl- is one carbon, and such no carbon bonds can be formed. Methylene is a functional group though, (-CH2). I think you probably mean methylene blue, which is the name of a common stain, that's often used to stain cells, DNA, and the such.

Answer 2

Ok, i guess when you added the other chemical to the skin, why did the field of view decrease. I think this means shy did the cells become harder to see, or see through. You saw less cells in the magnifying scope because it magnifies the cells further, say like there were 3 cells in the field of vision. Stain, is probably the die you used to emphasize the cells or whatever you are looking at. The stain was most likely the methylene.

Answer 3

Well I don't know the rest, but stain helps to emphasize the borders of everything so you can actually see it at close magnification. Helps to distinguish between different things. Even if something is colored with the naked eye, when we go that close up, it may not be the same color.

Oh and the stain was probably the methylene, although I'm not sure.