AP Biology: Grid In Questions

Grid-in items appear in Part B of Section I after the multiple-choice questions. Six questions are presented that require you to apply your scientific thinking and mathematical skills to calculate a response. Then you “grid in” your responses in the grid provided on your answer sheet, which will resemble the one shown here.

The next question is a sample grid-in item.

Part B Directions: Part B consists of questions requiring numeric answers. Calculate the correct answer for each question.

In a certain species of fruit fly, the allele for red eyes R is dominant to the white allele r.

A scientist performed a cross between a red-eyed fruit fly and a white-eyed fly. When crossed, 62 offspring result. Of these 62 offspring, 43 have red eyes and 19 have white eyes.

Calculate the chi-squared value for the null hypothesis that the red-eyed parent was heterozygous for the eye-color gene. Give your answer to the nearest tenth.

Just like Data Questions, Grid-In items require you to analyze the presented information carefully. You must identify the given information, determine the correct formula for solving the problem, make your calculations, and then correctly grid in the answer. Obviously, there is more room for error on the Grid-In questions and this should be factored in to your decision to “answer now” or “save for later.” Keep in mind, all things being equal, if you need to guess, you’ll have better odds guessing on a multiple-choice question, where the answer is actually given to you. As a case in point, would you rather pick the answer to the chi-squared question above from four answer choices, or grid in your own answer?

To help with the more quantitative problems on the AP Biology exam, you will be allowed to use basic four-function calculators (with square root). In addition, because these questions focus on applying math and not just recalling information, a formula list is provided for you.

Of course, the multiple-choice questions only account for 50 percent of your total score. Practice grid in questions to maximize the points you can get correct in this section! To get the other 50 percent, you have to tackle the free-response questions.