Question 1

Which of the following best describes the scientific method as practiced in real-world biological research?

Accepted Answer

A non-linear, iterative process where steps may be repeated and revisited as new information is gathered.

Question 2

A student is testing the effect of different amounts of sunlight on plant growth. Which is the independent variable in this experiment?

Accepted Answer

The amount of sunlight each plant receives.

Question 3

Which of the following is a good scientific question?

Accepted Answer

Does increasing the amount of fertilizer from 0g to 10g per plant increase the height of tomato plants after 30 days?

Question 4

Which statement about hypotheses is correct?

Accepted Answer

A hypothesis is a plausible, testable, and falsifiable statement that explains a possible relationship between variables.

Question 5

What is the main difference between a hypothesis and a prediction?

Accepted Answer

A prediction is a statement about what will occur, while a hypothesis provides an explanation or reason behind what is expected to occur.

Question 6

In an experiment testing the effect of a new drug on blood pressure, what is the purpose of the control group?

Accepted Answer

To provide a baseline for comparison by not receiving the drug treatment.

Question 7

Which of the following best describes a null hypothesis ($$H_0$$)?

Accepted Answer

There is no statistically significant difference between the groups being compared; any observed difference is due to chance.

Question 8

A researcher collects the following data set: 5, 7, 8, 10, 10. What is the mean ($$\bar{x}) of $$this data set?

Accepted Answer

$$\bar{x} = \frac{5+7+8+10+10}{5} = 8$$

Question 9

Which formula correctly calculates the standard deviation ($$s) of a $$sample?

Accepted Answer

$$s = \sqrt{\frac{\sum (x - \bar{x})^2$}{N-1}}$$

Question 10

If a data set is normally distributed, what percentage of the data falls within one standard deviation ($$\pm 1SD) of $$the mean?

Accepted Answer

68.3%

Question 11

A scientist calculates a mean of 20 and a standard error ($$SE) of 2. $$What is the 95% confidence interval for the mean?

Accepted Answer

16 to 24

Question 12

Which type of graph is most appropriate for displaying the distribution of a single continuous variable, such as plant height in a population?

Accepted Answer

Histogram

Question 13

In a controlled experiment, which variable is kept the same across all groups to ensure a fair test?

Accepted Answer

Constant (controlled variable)

Question 14

A researcher wants to compare the average test scores of two groups of students. Which statistical test is most appropriate?

Accepted Answer

Student's t-test

Question 15

Which of the following statements about scientific theories is correct?

Accepted Answer

Theories are tentative explanations that are supported by evidence but can be falsified by new data.

Question 16

A bar chart is most appropriate for which type of data?

Accepted Answer

Comparing the means of different groups, such as average plant height for different fertilizer treatments.

Question 17

If error bars representing $$\pm 2SE ($$standard error) for two groups do not overlap, what can you conclude?

Accepted Answer

There is a statistically significant difference between the groups at the 95% confidence level.

Question 18

Which of the following is an example of a qualitative variable?

Accepted Answer

Color of flower petals.

Question 19

A scatterplot is best used for which scenario?

Accepted Answer

Displaying the relationship between two continuous variables, such as temperature and dissolved oxygen.

Question 20

Which formula is used to calculate the standard error ($$SE_{\bar{x}}) of $$the mean?

Accepted Answer

$$SE_{\bar{x}} = \frac{s}{\sqrt{N}}$$

The Scientific Method + Biostats Study Guide

Study Guide - Practice Questions