Ap Biology Essay Question 1984

9The Advanced-Placement Biology Examination: Its Rationale, Development, Structure, and Results

Walter B. MacDonald

The advanced-placement (AP) biology course sponsored by the College Entrance Examination Board (College Board) is a national program that provides an opportunity for high-school students to pursue and receive credit for college-level biology coursework. The program is intended to replace biology courses that would normally be taken at the freshman or sophomore level in college and is based on the premise that college-level material can be taught successfully to able and well-prepared high-school students. The AP biology course is open to any high school that elects to participate; similarly, the AP biology examination is open to any student who wishes to take it. The AP examinations are administered once a year, in May, under standardized conditions at participating schools in the United States and many other countries. Most students take AP examinations in their own schools; others take them in multischool centers.

Development of the AP Biology Course and Examination

The policies of the AP biology course and examination, like those of the AP courses and examinations in other subjects, are determined by representatives of College Board member institutions and agencies throughout the country, including public and private high schools, colleges, and universities. The preparation of the course is an ongoing process, and the design of each examination typically begins nearly 2 years before the actual administration. Operational aspects of the examination—including the development of materials, scoring, and grading—are managed by the Educational Testing Service (ETS).

The AP Biology Development Committee, appointed by the College Board, is the "heart and mind" that prepares both the course description and the examination itself. The committee is made up of college professors and high-school AP teachers; these individuals are familiar with the academic standards to which college freshmen or sophomores are held. The committee is the authority for subject-matter decisions that arise in the test construction process. Committee members bring to their tasks knowledge of biology curricula and of laboratory methods; they are cognizant of the abilities and understandings that are critical to mastery of biology and how students might be asked to demonstrate these abilities and understandings.

Course Description

The AP biology course is taught by high-school biology teachers with guidance from Advanced Placement Course Description—Biology, a College and publication prepared by the Development Committee. The course description provides broad guidelines for the content and skills to be included in the course and offers a recommended set of quantitative laboratory exercises. In addition, the publication contains information about the examination, sample questions illustrative of those included in the examination, a list of recommended textbooks, and other materials and resources helpful in preparing and teaching a college-level biology course to high-school students. AP biology teachers also receive assistance in developing and teaching their courses from other publications and from workshops and special conferences.

Biology is a dynamic science; over the last few years, many new areas of inquiry have come to the forefront, while others previously emphasized in the discipline have receded. Sensing the need to reassess the content of biology instruction at the college level, the Development Committee surveyed the introductory biology courses at more than 80 colleges and universities across the country. Its primary goal was to obtain current information on what is taught so that the AP biology course syllabus could be revised to reflect collegiate course offerings more closely.

On the average, respondents participating in the survey were able to categorize about 99% of what they taught into the 10 major biological categories presented in a questionnaire. The average percentage of course time devoted to each of these categories and the average emphasis placed on 72 other subcategories and topics provided the information needed to update the AP biology curriculum.

The survey of colleges and universities also affirmed the view that laboratories still are a central part of biology instruction and that certain topics are covered in these laboratories with great frequency. To maintain parity between AP biology and college-level courses, the Development Committee has included sample laboratory experiments in the description booklet to augment any other laboratory experiments already taught by AP teachers. Most of the experiments in the booklet are patterned after those often included in colleges. The current AP biology topics, the approximate percentages of emphasis, and the topics of 12 laboratory experiments are outlined in Figure 1.

Figure 1

College Board's advanced-placement biology course and laboratory syllabus. From College Entrance Examination Board, 1988.

Structure of the Examination

The AP biology examination is 3 hours long and is designed to measure a student's knowledge and understanding of college-level biology. The examination consists of a 90-minute multiple-choice section with 120 questions that examines the learning of representative facts and concepts drawn from across the entire curriculum and a 90-minute, free-response section consisting of four mandatory questions that address broader topics. The number of multiple-choice questions taken from each major topic of biology reflects the weighting of that topic as designated in the course syllabus. In the free-response portion of the examination, one essay question focuses on molecules and cells, one on genetics and evolution, and two on organisms and populations. Any of these four questions may require the student to analyze and interpret data or information drawn from laboratory experiences, as well as lecture material; to design experiments; and to demonstrate the ability to synthesize material from several sources into a cogent and coherent essay. To allow students to show their mastery of laboratory science skills and knowledge, some questions in the multiple-choice section and one of the four essay questions may reflect the laboratory work and the objective associated with the AP biology laboratory exercises.

The multiple-choice section of the examination counts for 60% and the free-response section 40% of the student's grade. In order to provide maximal information about differences in students' achievements in biology, the examinations are intended to have average scores of about 50-60% of the highest possible score for the multiple-choice and free-response sections.

Using questions written by college faculty and AP teachers, the examination is assembled by ETS consultants to both content and statistical specifications. Each examination contains both new questions and a set of questions that have been included on previous examinations. The set of previously used questions, called the equating set, is a ''mini-test" assembled to both the content and statistical specifications for AP biology. The use of an equating set enables a new test to be equated to past tests. The analysis of student performance on an equating set allows statisticians to predict how previous AP students would have performed on a new examination or how the current AP students would have performed on past examinations. All the new questions used on a test are pretested on college students across the nation. The use of both pretested new questions and the equating set provides the statistical data to maintain an examination that is appropriate for college-level biology while keeping the level of examination difficulty relatively constant from year to year.

While the multiple-choice section of the examination is machine-scored, the free-response section is hand-scored by over 100 readers chosen from among college and high-school biologists nationwide who are actively involved in introductory college-level biology courses or an AP equivalent. The training of readers ensures uniformity of grading and strict adherence to carefully developed standards. All essays are graded on a 10-point scale.

The free-response score and the multiple-choice score are weighted and summed to produce a composite score with a 150-point maximum. Students are then assigned a grade of 5 to 1 based on a detailed analysis of the total scores for all students, on equating data from previously tested AP biology students, and on correlation checks to ensure test reliability. A score of 5 indicates that a student is extremely well qualified to pursue upper-level college biology courses, whereas a grade of 3 indicates average preparation.


Over the last 10 years, the number of students taking the AP biology examination has increased by about 11% per year. In 1988, about 31,000 students took the examination, compared with about 11,000 in 1978. In 1988, over 3,000 schools offered an AP biology course. That year, scores were sent to more than 1,000 colleges across the country. The results by sex, grade, type of school, and ethnicity are displayed in Table 1.

Table 1

1988 National Summary Data for Biology.

Over the years, the AP biology examination has maintained a relatively constant level of difficulty. The data from the equating set tend to indicate that recent populations of AP biology students are slightly less able than past populations. The mean score has steadily declined from 3.35 in 1981 to 3.05 in 1988. The reported grades for AP students since 1981 are displayed in Figure 2. For 1988, 25.2% of the students scored 3, 23.5% scored 2, 23.4% scored 4, 15.4% scored 5, and 12.5% scored 1; thus, 64% scored 3 or higher. Over the last 8 years, the percentage of students who received a score of 4 has remained relatively constant, the percentage at 5 has slightly decreased, the percentage at 3 has greatly decreased, and the percentages at 2 and 1 have increased.

Figure 2

AP biology reported scores, 1981-1988.

The AP biology program has experienced tremendous growth over the last few years. There now are more students earning scores of 5, 4, and 3 than in the past. Unfortunately, many more students are earning scores of 2 or 1. This increase in the percentages of students at 2 and 1 may be due to the addition of many new schools with novice AP biology teachers. While it is rewarding to teach a college-level course in high school, it is not easy. Often it takes time for the novice AP biology teacher to develop the skills, level of preparedness, and enthusiasm typical of the veteran AP biology teacher.

What topics do students who score a 2 or 1 not fully understand? A review of the multiple-choice questions on recent examinations shows that many of these students fail to comprehend such basic topics as osmosis, plant-animal cell differences, function of cell organelles, differences between photosynthesis and respiration, DNA replication, RNA transcription, meiosis, inheritance patterns, natural selection, blood circulation, digestion, antigen-antibody relationships, and phylogenetic relationships. Most students who score a 3 show average understanding of these topics, whereas students who score 4 or 5 exhibit excellent understanding of these topics and many others.

In 1987 and 1988, many of the students who scored a 2 or 1 could not score more than 1 on essay questions that asked them to:

Describe the production and processing of a protein that will be exported from a eukaryotic cell. Begin with the separation of the messenger RNA from the DNA template and end with the release of the protein at the plasma membrane [Educational Testing Service, 1987].


Discuss Mendel's laws of segregation and independent assortment. Explain how the events of meiosis I account for the observations that led Mendel to formulate these laws [Educational Testing Service, 1988].


Discuss the processes of cleavage, gastrulation, and neurulation in the frog embryo; tell what each process accomplishes. Describe an experiment that illustrates the importance of induction in development [Educational Testing Service, 1988].

Most students who scored a 3 could adequately answer these essay questions, whereas the students who scored a 5 or 4 were more likely to write more elegant and complete answers.


Generally, the state of the AP biology program and the status of AP biology students are very good. The majority of students are receiving a sound college-level course while attending high school. Validity and longitudinal studies have indicated that AP students perform as well as and often better than students taking the college course. Another important finding is that AP students tend to demonstrate higher achievement in college than their non-AP counterparts (Casserly, 1986). While one might expect AP candidates to show higher achievement in college than non-AP students because AP candidates are, in general, more able students, many AP candidates are placed in higher-level, more demanding courses when they reach college. Studies also have shown that 90% of the students who were placed ahead felt well prepared for the advanced sequence of college-level courses in which they then enrolled (Casserly, 1968). Other longitudinal studies have shown good correlation between scores on the AP biology examination and subsequent grades in introductory and upper-level biology courses in college (Willingham and Margaret, 1986).

An area of current and future concern is the increasing percentages of students who score 1 or 2 on the examination. It is hoped that the teacher preparation required to teach a college-level course in high school will catch up with the swelling population of AP students and precipitate a decrease in the percentages of students receiving scores of 1 and 2, while increasing the percentages of students receiving scores of 3, 4, and 5.

While participation by minority-group students in AP courses has increased over the last few years, a greater effort should be made to increase the participation of black and Hispanic students in AP biology courses. AP courses are a rewarding challenge that should be made available to all able students.


  • Casserly, P. L. 1968. What college students say about advanced placement. College Board Rev. 69: Fall.

  • Casserly, P. L. 1986. Advanced Placement Revisited. College Board Report 86-2. New York: College Entrance Examination Board.

  • College Entrance Examination Board. 1987. Advanced Placement Program—National Summary Reports. New York: College Entrance Examination Board.

  • College Entrance Examination Board. 1988. Advanced Placement Course Description— Biology May 1989. New York: College Entrance Examination Board.

  • Educational Testing Service. 1987. The 1987 AP Biology Examination. Princeton, N.J.: Educational Testing Service.

  • Educational Testing Service. 1988. The 1988 AP Biology Examination. Princeton, N.J.: Educational Testing Service.

  • Willingham, W., and M. Margaret. 1986. Four Years Later: A Longitudinal Study of Advanced Placement Students in College. College Board Report 86-2. New York: College Entrance Examination Board.

Walter B. MacDonald received his Ph.D. in ecology in 1983 from Rutgers University. Since joining the Educational Testing Service (ETS) in 1984, he has served as coordinator of the College Board's biology achievement test, as science coordinator of the College Board's Educational Equality Project, and as the College Board's member of ETS's Test Development Document Creation (TD/DC) project. Currently, Dr. MacDonald is director of test development for the National Assessment of Educational Progress.

Exam Information (AP Biology Exam from spring 2012 and prior)

Exam Content

The Topic Outline in the Course and Exam Description provides details about the content on the exam. About 25 percent of the multiple-choice questions are likely to be on the subject areas listed under Area I (molecules and cells). Similarly, one of the four essay questions will also be taken from that area; another question will be on Area II (heredity and evolution); and the remaining two questions will be on Area III (organisms and populations). In answering any of the four free-response questions, students may need to analyze and interpret data or information drawn from lab experience (as well as from lecture material) or to integrate material from different areas of the course.

Multiple-Choice Questions

For sample multiple-choice questions, refer to the Course and Exam Description (.pdf/490KB).

Past Free-Response Questions

Below are free-response questions from past AP Biology Exams. Included with the questions are scoring guidelines, sample student responses, and commentary on those responses, as well as exam statistics and the Chief Reader's Student Performance Q&A for past administrations.

Important Note About the "Form B" Exams

Because of the worldwide growth of the AP Program and the administration of exams in multiple time zones, another version of the AP Biology Exam, called "Form B," may be administered in order to maintain security.

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