Intro to Biology Midterm Review: P1Colin Cusack, Annika Patton, Marin Ros, Nadya Aminifard, Michael Peng

Key Vocabulary Hypothesis: a testable statement that

can be shown to be true or false through experimenting or observing

Experimental variable: the variable that receives some kind of treatment or condition (independent variable)

Control Group: receives no treatment, used to compare. It is important to have a control to compare and validate results

Graphing X-axis: where the INDEPENDENT

VARIABLE is plotted Y-axis: where the DEPENDENT VARIABLE

is plotted

Graphing Example

Label the x axis with years

Label the y-axis with the number of pairs

Plot the data

Writing a Conclusion1. Restate the overall purpose of the

experiment (include the independent variable and the dependent variable in this sentence.)

Ex. The purpose of the experiment was to investigate the effect of the IV on the DV.

Writing a Conclusion (cont)1. Restate the purpose2. What were the major findings?Ex. No significant difference existed between the height of the stressed plants and non-stressed plants.

Writing a Conclusion (cont)1. Restate the purpose2. Overall Findings3. Was the hypothesis supported?Ex. The hypothesis that the stressed plants would have a dramatically lower mean height was supported.

Writing a Conclusion (cont)1. Restate the purpose2. What were the major findings?3. Was the hypothesis supported by the

data?4. Improvements to experimentEx. This experiment could be improved by stimulating real-life stressors.

Writing a Conclusion (cont)1. Restate the purpose2. What were the major findings?3. Hypothesis supported?4. Improvements to experiment5. Further experimentsEx. Additional experiments could test various stresses being introduced at more frequent intervals.

More Vocabulary Dependent Variable: factor in an

experiment that a scientist wants to observe, which may change in response to the independent variable

Scientific Method1. Form a hypothesis2. Perform an experiment3. Gather data4. Analyze data5. Form a conclusion

REVIEW QUESTIONS!!!

1) What is the right order of these steps in writing a conclusion?

a) Restate the purpose, major findings, improvements, hypothesis, further experiments

b) Major findings, purpose, further experiments, improvements, hypothesis

c) Purpose, major findings, hypothesis, improvements, further experiments

d) Hypothesis, purpose, improvements, major findings, further experiments

2) A hypothesis is…a) A testable statement that can be

shown to be true or false by experimenting and observing

b) A final result after an experimentc) A testable statement that is always

rightd) A guess

3) Where would you put variables on a graph?a) Independent on x, dependent on yb) Dependent on y, independent on xc) Control on x, independent on yd) Dependent on y, control on x

4) What is an independent variable?a) The variable being tested in an

experimentb) The variable that stays the samec) The variable that is changedd) All the variables except for the one

being tested

5) What is a control group?a) The thing being testedb) The variable that is changed in an

experimentc) The variable that is not changedd) All the things that stay the same

6) What is the right order of the scientific method?a) Experiment, hypothesis, gather data,

analyze data, form a conclusionb) Hypothesis, experiment, gather data,

analyze data, form a conclusionc) Conclusion, analyze data, hypothesis,

experimentd) None of the above

7) What is the experimental variable?a) The variable being testedb) The variable that stays the samec) The variable that we know the least

aboutd) The variable that we know the most

about

8) Why is it important for an experiment to contain a control?a) So no one gets hurt while

experimentingb) So we can compare results and

variablesc) So that the effect of the independent

variable is greaterd) So we can see the efforts of the

different group members

9)Referring to the graph, what are the independent and dependent variables?

a) Years= dependent, # of pairs= independent

b) # of pairs= dependent, Years= independent

c) None of the above

10) What is a dependent variable?a) It is the variable that we changeb) It stays the samec) It reacts to the independent variabled) It is plotted on the x axis

ANSWERS!!

Answer Key1) C2) A3) A4) C5) D6) B7) A8) B9) B10) C