1. Simple optical microscope. One lens.
Disadvantage: Only Van Leeuwenhoek made them, and he's dead.
Advantage: Worked pretty well. With them, Van Leeuwenhoek discovered protozoa and bacteria.
2. Compound optical microscope. Has both an ocular and objective lens.
Disadvantage: limited resolution. Can resolve bacteria, but not smaller things like viruses.
Advantage: can be used with live specimens (using phase contrast or polarized or other special illumination).
3. Binocular dissecting microscope (optic). Has a pair of ocular and objective lenses, and supposedly presents a "3D" view of the specimen to the viewer (I was never able to see in 3D using these darn things).
Disadvantage: Limited magnification
Advantage: Can be used to perform surgery on small but not microscopic specimens, such as fruit flies. Is used in "microsurgery" in hospitals too.
Hope this helps buddy!
What does this mean for us? Water's polarity allows it to dissolve other polar substances<span> very easily. When a polar substance is put in water, the positive ends of its molecules are attracted to the negative ends of the water molecules, and vice versa.
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D can be eliminated because the temperatures where changed in 3 ways, not two.
A is true, but doesn't apply to the actual experiment "design"
B we don't know for sure, it just looks like a cup/glass.
Best answer for you: C
C is true- it was tested with a single independent variable (one that does not change) on multiple trials (the different temperatures)
The blood is collected in heparinized capillary tubes to prevent clotting. Heparin is a blood thinner and this anticoagulant is produced naturally by mast cells and basophils. But heparin can not dissolve or break the preformed clots.
The first choice is correct
