AP Biology Free Response Questions

Combining big ideas and tiny details

Free Response

• “provide appropriate scientific evidence and reasoning to support their responses”

• “can draw upon the illustrative examples”• “any other appropriate, relevant examples”

What are you being asked to do?When developing their reasoning and selecting supporting evidence to demonstrate understanding, a student might consider applying the following strategies:Relate a proposed cause to a particular biological effect (e.g., if asked, What is the evidence that a single mutation caused the phenotypic change seen in an organism?)Identify assumptions and limitations of a conclusion (e.g., if asked, If a nutrient has a positive effect on one plant, can you appropriately conclude that it is effective on all plants?)Connect technique/strategy with its stated purpose/function in an investigation (e.g., if asked, Identify the control from a list of experimental treatments.)Identify patterns or relationships (and anomalies) from observations or a data set (e.g., if asked, Is the behavior of an organism the same in different environments?)Rationalize one choice over another, including selection and exclusion (e.g., if asked, Which question from this list of questions can best be investigated scientifically?)

So, how to get full credit?

• Don’t panic—think.• Make sure you understand what the question

is asking you to do!• This is as important as knowing the science

facts.• Make an outline so you will not forget a

segment of the answer.• Use complete sentences and paragraphs.

Magic Words• Identify: Name one or more items, list the

parts, or give an example (meaning depends on context).

• Define: Give a meaning for a word or phrase.• Describe: Provide details in words that help

someone visualize or construct a mental model of the object being discussed.

• Explain: Say why or how something happens. The answer should give reasons, not just a description.

Magic Words• Compare: Consider two or more objects or concepts and

point out what is similar.• Contrast: Consider two or more objects or concepts and point

out what is different. • “Compare and contrast” is a standard phrase asking for both

similarities and differences—it is not asking for explanations or descriptions of the objects separately, but only of their similarities and differences. Listing “X has A, B, and C, and Y has C, D, E” is not an answer, but the same content expressed as “X and Y both have C. A and B are properties of X but not Y, while D and E are properties of Y but not X” does answer a compare-and-contrast question. The graders are picky about this sort of trivial presentation change, so be sure to present things in precisely the form the questions asks for.

Magic Words• Discuss: Consider different theories or points

of view. • This is a more general prompt than the others,

often asking for all of the above aspects.

Scoring Guidelines

What follows is not the answer to the question. It is a shorthand, coded list of possible information that scorers use to help them decide whether to give students points.

The student earned 0 points for part (a) because the response did not include plausible explanations for the most likely genetic changes that produced the polypeptide sequences in species II and species III.

The response earned 1 point in part (a) for explaining that the most likely genetic change in species II was a point mutation in which a single nucleotide is altered, and the amino acid being coded for was changed.The response earned 1 point in part (a) for explaining that the most likely genetic change in species III was a point mutation that coded a STOP codon, which halted the production of the polypeptide prematurely.

More Scoring Guidelines

The response earned 1 point in part (b) for predicting that a frameshift mutation in species IV causes a much different protein structure and a radically different protein function.

The response earned 1 point in part (b) for justifying the prediction by stating that the polypeptide chain was completely altered, which changed the interactions between the amino acids of the protein and caused the protein's function to shift.

The response earned 1 point in part (b) for predicting that the structure and function of the protein in species IV will be significantly changed.

The response earned 1 point in part (b) for justifying the prediction by stating that a structural and functional change in the protein is due to changes in the order and content of its amino acids.

Tough love

• This is really hard to do well on the exam—that’s what it’s possible to make a 3 getting about half the possible points.

• When this is a homework assignment with lots of time, you need to work hard enough and long enough to make it perfect.

• But don’t yammer on—more does not mean better, and it will tick off your reader.