Microscope, Cells, and Organelles Lab
Part 1
Table 1. Microscope magnification.
Lens mag. Ocular mag. Total mag.
a. Scanning 4x 10x =40x
b. Low Power 10x 10x =100x
c. High Power 40x 10x =400x
d. Oil Immersion 100x 10x =1000x
Part 2
Cheek Smear
1. Nucleus
2. Cytoplasm
3. Cell membrane
Onion Root
1. Nucleus
2. Nucleolus
3. Cell membrane
1. How might the thin, flat shape of cheek cells relate to their function?
Cheek cells are thin and flat so they can have many layers that protect the inside of the mouth.
2. What structure separates the contents of the nucleus from the cytoplasm?
The nuclear membrane separates the nucleus from the cytoplasm.
3. What is the function of the nucleoli? Why is this important?
The nucleoli houses the parts to synthesize ribosomes. This is important because ribosomes create
specific proteins for the body.
4. Other than the nucleoplasm and nucleoli, what are three other materials found in the nucleus?
Three other materials found in the nucleus are DNA, RNA and small proteins.
5. When you begin, in what position should the condenser be?
The condenser should be kept in the highest position.
6. What objective should be in place when you start?
The objective should be placed on 4x.
7. Which focusing knob do you first use when you begin looking at a slide?
The focusing knob you first use when looking at a slide is the course adjustment.
8. What do you adjust if you can see two overlapping circles with part of the object in each circle?
You should adjust the oculars if you see two overlapping circles in the view.
9. How do you move the slide on the stage?
To move the slide on the stage use the adjustment knobs that are attached to the clips on the stage.
10. What device can be opened to increase light?
The diaphragm can be opened to increase light to the slide.
11. What is the name of the highest magnifying objective?
The highest magnifying objective is called oil immersion.
12. What materials are used to clean slides?
The materials used to clean slides are soap and water.
13. What materials are used to clean objectives?
The materials used to clean objectives are lens paper and cleaner.
14. Explain the procedure for stowing the microscope.
After cleaning the microscope the procedure for stowing is to center the stage, make sure all parts
tucked in, wrap the cord around the arm or head, then place on the shelf with its matching number.
15. Describe two ways you can decrease light intensity?
Two ways to decrease light intensity is by adjusting the diaphragm and the lamp.
16. Which objective allows you to see the largest area of the object that you are viewing?
The objective that allows the largest area for viewing is the 4x objective.
Part 3
I think that the carrot that is placed in the saltwater will expand, because salt will cross it's barrier membrane and move inside the carrot. I think this will happen because there is not a lot of salt inside the carrot so the salt will move to where a lower concentration exists.
Table 2. Starting and Ending Carrot Measurements.
Start End Start End
Freshwater Carrot 8"L 7 1/2"L 1"W 1 1/8"W
Saltwater Carrot 8"L 7 1/4"L 1"W 7/8"W
Observations:
The string on the saltwater carrot was significantly looser than the string on the freshwater carrot. The string on the fresh water carrot was also somewhat tighter than it was in the beginning of the experiment. The texture of the saltwater carrot was smoother, while the fresh water carrot had some splitting.
The saltwater carrot seemed to have a decrease in cell size.
The saltwater cell seemed to have lost water, while the freshwater cell seemed to have gained water.
The measurements showed that the saltwater carrot decreased in length by 3/4 of an inch and 1/8 of an inch in width, while the freshwater carrot decreased in length by 1/2 inch, but increased in size by 1/8 inch. It seems that the freshwater carrot cell increased in size making the whole carrot swell. The saltwater carrot cell actually decreased, shrinking the width and length of the cell. The carrots actually did the opposite of what I thought they would do in my original predictions!
What is Osmosis?
Osmosis is the movement of substances from high concentration to low concentration through a selectively permeable membrane. Small molecules, small substance, and water can pass through the membrane, however, larger substances and molecule cannot. It largely depends on what the membrane will allow. This is important for the health of cells, because if the membrane allowed everything through its barrier than the cell could rupture or get substances that prevent it from working properly.
