Question

1. a possible explanation for an observed set of facts is called a (a) variable. (b) control. (c) hypothesis. (d) theory.
2. the ability of a microscope to show two points close together as separate images is called (a) magnification. (b) mechanical system. (c) resolution. (d) microdissection.
3. an explanation that applies to a broad range of phenomena and that is based on well - established evidence is known as a (a) control. (b) variable. (c) hypothesis. (d) theory.
4. a type of microscope that does not use light is the (a) stereomicroscope. (b) phase - contrast microscope. (c) scanning electron microscope. (d) compound microscope.
5. in a controlled experiment, the factor that changes is known as the (a) variable. (b) hypothesis. (c) control. (d) theory.
6. which of the following is not a unit of measurement in the metric system? (a) meter (b) liter (c) inch (d)
7. how many millimeters are in 9 meters? (a) 0.9 (b) 90 (c) 900 (d) 9000
8. the coarse adjustment knob is used to (a) regulate light. (b) concentrate light on the specimen. (c) focus with the low - power objective. (d) focus with the high - power objective.
9. the total magnification of a compound microscope is 45 x. if the ocular power is 15 x, then the objective power is (a) 30 x. (b) 3 x. (c) 10 x. (d) 1 x.
10. the technique for separating substances made up of particles that have an electrical charge is (a) centrifugation. (b) chromatography. (c) electrophoresis. (d) spectroscopy.

Explanation:

Step1: Recall definitions

A theory is a possible explanation for an observed set of facts.

Step2: Know microscope - related terms

Resolution is the ability to show two points close together as separate images.

Step3: Define scientific concepts

A theory applies to a broad range of phenomena and is based on well - established evidence.

Step4: Identify microscope types

A scanning electron microscope does not use light.

Step5: Understand experiment factors

In an experiment, the changing factor is a variable.

Step6: Recall metric units

A meter is a unit of length in the metric system.

Step7: Convert units

1 m = 1000 mm, so 9 m = 9000 mm.

Step8: Know microscope parts

The coarse adjustment knob is used to focus with the low - power objective.

Step9: Calculate objective power

Total magnification = ocular power × objective power, so objective power = 45÷15 = 3X.

Step10: Recall separation techniques

Electrophoresis is the technique for separating substances made up of particles with an electrical charge.

Answer:

1. (d) theory
2. (c) resolution
3. (d) theory
4. (c) scanning electron microscope
5. (a) variable
6. (a) meter
7. (d) 9000
8. (c) focus with the low - power objective
9. (b) 3X
10. (c) electrophoresis