AP Biology

Labs, Exams, and Essays Guide

AP Exam

• The AP exam is 3 hours long

– 90 minutes for 63 MC and 6 math questions

– 90 minutes for 8 essay questions (you are graded on all of them and you don’t get to pick)

• One essay question is ALWAYS lab-related

• 2 long essays, 6 short essays

• Multiple choice questions are graded by a computer and account for approximately 50% of the final score

• Essay questions are graded by a team of “readers” and are 50% of the final score.

AP Exam—MC Questions• Anything in the textbook is fair game.

– Lectures focus on the most important concepts, but should not be viewed as all you need.

• Stand alone questions

– Require you to remember specific information

• Scenario questions*

– Analyze given information in a problem (so you have to read everything)

• Lab questions*

– More focused on knowing how to do proper science.

• *Often, answers are found hidden in the question

Stand-Alone Question• What is meant by an organism's “fitness” in an

evolutionary sense?

a) The organism survives to adulthood

b) The organism survives to adulthood and finds a mate

c) The organism survives to adulthood and reproduces fertile offspring.

d) The organism is not killed before adulthood

• (To answer the question, you simply need to remember the definition “fitness is the ability to reproduce”)

Scenario Questions• The following data table shows the makeup of air when it

is inhaled and when it is exhaled from the human body. How much oxygen is absorbed/carbon dioxide is exhaled? Express your answer as a percent.

• In this case, all you have to do is subtract two numbers from either inhaled air or exhaled air. The skill here knowing how to read the table.

Gas Inhaled Air Exhaled Air

Nitrogen 78.00% 78.00%

Oxygen 21.00% 16.54%

Carbon Dioxide 0.03% 4.49%

Scenario Questions• Lab Questions• A customer observed that a particular potted plant in a restaurant

was bigger and greener than other plants in the room. When asked, the owner said that he poured leftover club soda (carbonated water) into that plant’s pot every day. Which of the following best explains how the club soda affected that plant’s growth?A) The temperature of the club soda promoted faster growth

B) Oxygen bubbles from the club soda oxygenated the soil

C) The roots absorbed the CO2 necessary for photosynthesis

D) The roots received more moisture, and the leaves were exposed to more CO2.

• Notice in the question they mentioned “carbonated” water, and in two answers “CO2” is mentioned.

Question Types• Question: What do you do if you come to a question and

you have no idea whatsoever?

• Guess what…it WILL happen. A lot.

– Narrow down your possible answers to 3 or 2 if you can. Then guess.

– You DO NOT lose credit for guessing, so you can’t lose.

– No one is trying to trick you. Trust your instincts.

– If you have no idea, use common sense. Try to think of connections to things you do know.

– Look for hints within the test as well

• You better get used to this because it’s impossible to know everything.

AP Exam—Essay questions• Readers travel from all across the country to sit in

a warehouse in Kansas City in June and grade your essays.

• They are given a single essay question and a set of criteria for how to grade that essay question

• They then spend 8-9 hours a day for 7 days doing nothing but grading this one question over and over and over and over and over and over and over and over and

over and over and over and over and over…

• Each reader will give your essay question about 2 minutes of attention.

AP Exam• Some helpful tips when writing your essay

– You don’t need an introduction or conclusion. These essays aren’t really essays.

– DO NOT USE BULLETS. Repeat: DO NOT USE BULLETS!!!

– Think about what you’re going to say first before writing it down.

– Be clear and use complete sentences. Do not expect that they will simply “know what you mean.” They wont.

– Reread the question and make sure you have answered everything they tell you to. A little information answering all questions is better than tons of info answering one question.

– If you don’t know, guess. They are allowed to award partial points and you do not have points subtracted for wrong answers.

– Bottom line: make it easy for your reader!

AP ExamBig Idea #1: The process of evolution drives the diversity and unity of life

Big Idea #2: Biological systems utilize free energy and molecular building blocks to grow, to reproduce, and to maintain dynamic homeostasis

Chapters 11, 12, 15, 16, 17, 18, 19, 23, 31 Chapters 1, 2, 3, 7, 8, 27, 32, 33, 34, 35, 36

Big Idea #3: Living systems store, retrieve, transmit, and respond to information essential to life processes

Big Idea #4: Biological systems interact, and these systems and their interactions possess complex properties

Chapters 4, 5, 9, 10, 13, 14, 24, 25, 26 Chapters 6, 43, 44, 45, 46, 47, 37, 38, 39, 40

AP Exam

•Lab 12: Animal Behavior•Lab 10: Stupid. We’re skipping it.•Lab 4: Diffusion and Osmosis•Lab 13: Enzyme Catalysis•Lab 5: Photosynthesis•Lab 6: Cellular Respiration•Lab 7: Mitosis and Meiosis•Lab 1: Genetics of Fruit Flies•Lab 8-9: pGLO and DNA Fingerprinting•Lab 2: Hardy-Weinberg Equilibrium•Lab 3: Cladogram Evolution•Lab 11: Transpiration

AP Labs

• The 13 AP labs covered in this class account for 25% of your grade.

• At least one essay question on the AP exam will refer to or directly ask about the labs.

• For these reasons, it is important you pay special attention and effort to your lab write-ups

• It is also important that you hold onto your lab book so that you can study these labs in April to prepare for the exam.

AP Labs

• Objective

– 1-2 sentences maximum

– Why do we care about this lab? I’m not making you do it to pass the time, there’s something you’re supposed to learn from it.

– (You know that little paragraph at the beginning of assignments that you never, ever read? Usually that’s where you find this)

AP Labs• Manipulated and Responding Variables, and Controls

• The MV is what is adjusted in each trial you run. It is not necessarily something YOU adjusted

• The RV is whatever result you are collected. You have no manipulation of this whatsoever

• Controls must be something you actually have control over AND if changed would alter the experiment

– Be specific. Write out in full sentences.

– Bad: our controls were the trays, the pillbugs, and the filter paper.

– Good: we used the same species of pillbugs for all trials; the filter paper was the same type and size for both trials. Each paper received the same amount of water (salty or sugary).

AP Labs

• Your hypothesis must be in “if/then” format. It should always read like this:

• If (state your manipulated variable), then (state your responding variable) because (state a PLAUSIBLE explanation).

• Your explanation doesn’t have to be correct. But it does have to be reasonable and come from coherent thought.• Bad: Pillbugs will choose black paper because they like it.• Good: If we give pillbugs a red or black-bottomed habitat,

then they will walk toward the black habitat because it allows them to blend in more.

AP Labs

• If you are writing tables, they should be filled in entirely.

• When writing observations, “Nothing happens” never happens. Something is always happening.

• No matter what is going on, make a note of it. That lets the reader know you were still paying attention and didn’t go get a snack or something.

AP Labs

• Graphs need the following components:

– Title

– Labels for x and y axis

– Data for x and y axis

– Labels/key for the graph itself

– Choose an appropriate graph

• Line, bar or pie are really the only ones you should use

– Make your lines obvious and neat. Use straight edges and don’t guess.

– Make it big enough to read easily

Bad

Good

AP Labs• A good conclusion contains the following:

– “Conclusive Statement.” Summarize the hypothesis and whether the experiment supported it.

– “Supporting Data.” Provide 2 data points to back up your conclusive statement (not any 2 random points).

– “Explanatory Language.” Explain how the supporting data backs up your conclusive statement.

– “Error Analysis.” Describe the constraints you experienced in this experiment.• *NOTE* This is NOT where you didn’t follow procedure. This is either an

unavoidable problem with the lab or an unforeseen error. Help future experimenters avoid or overcome this problem in the future.

– “Scientific Explanation.” What overall lesson is to be taken from this experiment? (Remember your “objective”)

AP Labs

• Conclusion: Bad

– Our hypothisis was proven. We now know pillbugs enjoy chocolate more than they like vanilla cause its sweeter.

• 1) Watch your spelling! Yes, it counts.

• 2) Don’t be overconfident. Nothing is ever proven in one experiment.

AP Labs

• Conclusion, GOOD:

– In conclusion, our hypothesis was rejected. We thought the pillbugs would prefer the chocolate over the vanilla, but 8 out of 10 bugs stayed near the vanilla. We also noticed that once they found the vanilla, they didn’t leave. This was confusing to us because the vanilla didn’t allow the pillbugs to blend in as much as the darker chocolate would have. Perhaps the bugs really did enjoy the scent or taste of vanilla more than chocolate and it was worth being exposed.

AP Labs

• The “Next Experiment” question gets asked at least once every AP exam.

• The purpose of the question is to show you can analyze what you’ve done and take it to the next step

• It should be

– Related to the previous experiment

– Should use information learned in the previous experiment (not just a new random experiment)

– Clearly explain WHY you are doing this experiment.

AP Labs

• Bad: After the pillbug experiment, the next thing we will do is see whether bugs like hot or cold water.

• Good: After the pillbug experiment, where we saw that bugs preferred dark areas to light areas, we want to place the bugs in lighted areas that are both warm and cool. This is because we want to learn whether the bugs preferred darkness due to protection or due to the warmth it provided.

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Lab 12 Lab 4 Lab 13 Lab 6 Lab 5 Lab 1 Lab 7

Overall scores of students who tracked vs didn't

Trackers

Non Trackers

Difference in Grades (Trackers-Non-Trackers)

Linear (Trackers)

Linear (Non Trackers)

Linear (Difference in Grades(Trackers-Non-Trackers))

A head’s up for the year…

The student who struggles… The student who succeeds…

…puts the bare minimum effort. …puts in the needed effort.

…cares about receiving good grades. …cares about earning good grades.

…never reviews their previous errors …learns from and fixes previous errors

…only studies the night before exams …does regular studying 5 days a week

…always studies the same way …tries new methods of studying

…is afraid of being imperfect …learns from mistakes and will take risks

…makes learning the lowest priority …makes learning the highest priority.

• Your priority should be to learn the material and concepts. If you learn, then the good grades, the low stress, and confidence will all follow.

Bottom Line

• Get used to not taking short cuts (writing complete sentences, reading rubrics, planning labs ahead, etc)

• Give graders no choice but to award you full credit.

• Get in the habit of working hard. Before you know it, the pace of the class will feel normal.

• Sleep is good. Get 8 hours every night. If it’s 10:00, I don’t care if you have more studying to do. Go to bed.

• Good luck and have a fabulous year!