Let's address each of the first three questions one by one.
The $\qquad$ causes the stage to move upward or downward.
Select one:
a. mechanical stage
b. iris diaphragm
c. objective lens
d. coarse adjustment knob
The answer is d: coarse adjustment knob.
Explanation:
- a. mechanical stage: This is the platform where the slide is placed, and it can be moved horizontally but not vertically.
- b. iris diaphragm: This controls the amount of light that reaches the specimen but does not move the stage.
- c. objective lens: These are the lenses closest to the specimen and do not move the stage.
- d. coarse adjustment knob: This knob is used to move the stage up and down to bring the specimen into focus.
Sally flips the switch to turn on the light in her bedroom and the light does not come on. She notices that all the other lights in the house work. She wonders if the light bulb in her room has burned out. Sally gets a new light bulb and uses it to replace the old light bulb. She turns on the switch and the light works. Thinking the light bulb is bad is which of the following?
Select one:
a. Theory
b. Experiment
c. Conclusion
d. Observation
e. Hypothesis
The answer is e: Hypothesis.
Explanation:
- a. Theory: A theory is a well-substantiated explanation of some aspect of the natural world.
- b. Experiment: An experiment is a procedure carried out to support, refute, or validate a hypothesis.
- c. Conclusion: A conclusion is a summary of the results of an experiment.
- d. Observation: An observation is the act of noting and recording something with instruments.
- e. Hypothesis: A hypothesis is a proposed explanation for a phenomenon, which can be tested. Sally's thought that the light bulb is bad is a hypothesis.
When you overexert yourself in the gym your muscles begin to burn. The burning sensation is because of the build-up of acid in your muscle cells. What is the primary cause for the build-up of that acid?
The primary cause for the build-up of acid in muscle cells during overexertion is the accumulation of lactic acid.
Explanation:
When muscles are overexerted, they may not get enough oxygen to meet their energy needs through aerobic respiration. As a result, the body switches to anaerobic respiration, which produces lactic acid as a byproduct. The accumulation of lactic acid in the muscles leads to the burning sensation.
Summary:
- The coarse adjustment knob causes the stage to move upward or downward.
- Thinking the light bulb is bad is a hypothesis.
- The primary cause for the build-up of acid in muscle cells during overexertion is the accumulation of lactic acid.