Question 1

A student is using a compound microscope with a 10x ocular lens and a 40x objective lens. What is the total magnification being used?

Accepted Answer

400x

Question 2

You are given a microscope slide with a cell. The field of view under 100x total magnification is 2 mm. If the cell occupies half the field of view, what is the approximate size of the cell in micrometers ($$\mum$$)? (1 mm = 1000 $$\mum)$$

Accepted Answer

$$1000\ \mu\mathrm{m}$$

Question 3

Which of the following is the correct order of adjustments when focusing a compound microscope from lowest to highest magnification?

Accepted Answer

Coarse focus at low power, fine focus at low power, switch to high power, fine focus at high power

Question 4

A researcher wants to test if a new fertilizer affects plant growth. Which of the following is a suitable null hypothesis?

Accepted Answer

The new fertilizer has no effect on plant growth compared to the control.

Question 5

In a chi-square test, the calculated $$\$$chi^2$$ value is 5.2 with 2 degrees of freedom. Using the critical values chart, what is the correct interpretation if the significance level is p = 0.05$?

Accepted Answer

Reject the null hypothesis because $$5.2 \u003e 4.61 is $$true; $$p \u003c 0.10.$$

Question 6

Which of the following best describes the dependent variable in an experiment measuring the effect of pH on enzyme activity?

Accepted Answer

The rate of enzyme activity

Question 7

A spectrophotometer is used to measure the absorbance of a solution. What does a higher absorbance value indicate about the solute concentration?

Accepted Answer

The solute concentration is higher

Question 8

Which of the following is a common source of error in spectrophotometric measurements, and how can it be corrected?

Accepted Answer

Fingerprints on the cuvette; clean the cuvette before use

Question 9

If the temperature of an enzyme-catalyzed reaction is increased beyond the enzyme's optimal temperature, what is the most likely effect on enzyme activity?

Accepted Answer

Enzyme activity will decrease due to denaturation

Question 10

A student is graphing the results of an experiment with time (minutes) and absorbance. Which variable should be plotted on the x-axis?

Accepted Answer

Time (minutes)

Question 11

You are given the following observed and expected data for a chi-square test: Observed = [20, 30], Expected = [25, 25]. Calculate the $$\$$chi^2$$ value using $$\$$chi^2$$ = \sum \frac{(O_i - E_$$i)^2$$}{E_i}$$.

Accepted Answer

$$2.0$$

Question 12

Which of the following best explains why a null hypothesis must be testable and falsifiable?

Accepted Answer

So that experimental results can objectively support or refute it

Question 13

A solution appears dark red and has a low percent transmittance when measured in a spectrophotometer. What does this indicate about the solution's pigmentation?

Accepted Answer

The solution has a high concentration of pigment

Question 14

Which of the following would be the most appropriate graph type to represent the relationship between enzyme activity (rate) and temperature (continuous variable)?

Accepted Answer

Line graph

Question 15

In an experiment, the degrees of freedom for a chi-square test are calculated as the number of categories minus one. If there are 5 categories, what are the degrees of freedom?

Accepted Answer

$$4$$

Question 16

A student is asked to suggest additional data for a graph showing the effect of light intensity on photosynthesis rate. Which of the following would be most useful?

Accepted Answer

Temperature of the environment during the experiment

Question 17

If a chi-square test yields a p-value of 0.03, what does this indicate about the null hypothesis at a significance level of 0.05?

Accepted Answer

Reject the null hypothesis; there is a statistically significant difference

Question 18

Which of the following best describes the independent variable in an experiment testing the effect of different sugar concentrations on yeast fermentation rate?

Accepted Answer

Sugar concentration

Question 19

A student measures the absorbance of a solution at two different wavelengths and gets different values. What is the most likely explanation?

Accepted Answer

The solution absorbs light differently at different wavelengths

Question 20

Why is it important to use a blank (such as distilled water) when calibrating a spectrophotometer before measuring sample absorbance?

Accepted Answer

To account for absorbance by the solvent and cuvette

General Biology Lab Skills: Microscopy, Scientific Inquiry, Spectrophotometry, and Graphing

Study Guide - Practice Questions

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