Design an experiment—Essay
of the past National AP Biology lab based essay questions have asked
students to “Design and experiment to…”
are usually some common points in any question of this type. Here are some
Say the word “hypothesis” and write in the “If…then…” format.
The hypothesis for this experiment is if higher light allows
more photosynthesis, then the plants with the most light should
have the most mass.
(or constants)- use the word “control”, but also
indicate several variables that are being held constant.
plants of the same species, from the same seed source, grown
in the same soil and under the same conditions.
sure to indicate “which treatment” is serving as the control if you have a
separate control group.
Manipulation of the Variable
- Tell how
the experiment is manipulated (i.e. what are your treatments). Give a full
range of the treatment if possible to avoid the “Three Bears Syndrome”
(one too hot, one too cold, one just right)
The plant will be grown in five treatments of differeing
temperatures from 0 degrees to 40 degrees in 10 degree intervals.
to the reader what is being measured. Use quantitative measurements
rather than qualitative.
when the measurements will be taken.
The mass of the plants will be taken in grams at the beginning
and end of the experiment.
- Use a
large sample size (i.e. the “rule of 10X”) or show that the
experiment will be repeated several times.
There will be 10 plants in each treatment and control group.
the reader what you expect the results of the experiment to be and
The expected results of the experiment is that the plants with more light
will have more photosynthesis, therefore, they
should have more biomass.
Essay Exam and Quiz Scoring
- Gain points for correct statements.
- No point deduction for wrong answers.
- Must give examples and specific details to gain points. (up to 10 oer question)
- Answers must be in full sentences, not in outline form.
- Drawings permitted, but must be explained
Essay Exam Tips
- Read the question carefully!!!!
- Outline your possible answers, then begin to write.
- Give details and specific examples.
- If question is in parts, write the answer in parts.
- Underline key words or phrases.
- Don't rewrite the question or use the 5 paragraph format.
- NEVER leave an essay question blank. Write definitions to the key words in the question if nothing else.
- Don't assume the writer will "know" what you mean. Give defitions to all terms. (write in parenthesis after the first use of the term in your answer)
- WRITE, WRITE, WRITE!!!!!!!
- Writing the essay exam answers is a learned skill. Expect to get better with each exam.
Essay Exam Tips- if multiple essays on test
- Answer the "easiest" essay question first.
- Spend equal amounts of time on each question.
- Don't refer reader to answer written in another question.