AP Biology

What’s the Format of the AP Biology Exam?

The AP Biology Exam is a long test, three hours long to be exact. Like other AP tests, it has two parts, a multiple-choice section and a free-response section (each of which is worth 50 percent of your score), although these sections are divided further into different types of questions.

The multiple choice section has 63 actual multiple-choice questions and six grid-in questions, which are essentially short-answer math problems. This section is one hour and 30 minutes total. Each multiple choice question has four choices, down from five in earlier versions of the exam. 

Even though you technically have more than a minute for each question, I would recommend keeping your time under a minute per multiple-choice question on your first pass through the section. You should also take into account the fact that the grid-in questions may be more time-consuming. There is no guessing penalty, so you should answer every question even if you have no idea which choice is correct (after you’ve tried to figure it out of course!).

The free-response section has eight questions total: six short-response questions and two long-response questions. This section takes up the remaining hour and thirty minutes of time. There is a 10 minute reading period at the beginning of the free response section. You’ll need to pace yourself wisely on this section as well. Try to spend no more than five minutes on each short free-response question. Even though they technically come after the long questions, I’d recommend doing the short questions first to get yourself warmed up. If you manage your time well, you’ll have at least 20-25 minutes left for each of the long free-response questions. 

Here’s a chart showing the format of the exam.

  Multiple-Choice Section Free-Response Section
Length 90 minutes 90 minutes
Number of Questions 63 multiple choice 6 grid-in 6 short response 2 long response
Percentage of Total Score 50% 50%

 What Topics Does the AP Biology Exam Cover?

The College Board says in its Course Description that AP Biology has changed its focus from the more memorization-based curriculum that defined the course and exam in the past. The goal is for students to gain a deeper conceptual understanding of topics in biology. Reasoning skills and knowledge of the process of scientific inquiry are more important on the current AP Biology test than they have been before. 

The College Board has tried to structure the exam so that content knowledge and reasoning skills are intertwined. This can be both good and bad: the good is that you won’t necessarily have to memorize as many little tidbits of information, the bad is that it can be harder to study for a test like this that covers more abstract forms of knowledge. More on how to manage this in the “How to Review” section! 

The exam and curriculum as a whole will be centered around your understanding of these four “Big Ideas,” which each cover a bunch of different topics. Your success on the exam rests on being able to connect specific concepts with the overarching Big Ideas that define the course. 

Big Idea 1: The process of evolution drives the diversity and unity of life


  • Natural selection
  • Hardy-Weinberg
  • Biodiversity and categorization of organisms

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


  • Molecular biology
  • Biological systems and reactions
  • Photosynthesis
  • Cellular respiration
  • Cell structure
  • Cell membrane properties (diffusion and osmosis, proteins)
  • Thermodynamics/homeostasis
  • Immune response

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


  • Genes and gene mutations
  • Cell cycle (mitosis, meiosis) and cell communication
  • Mendel and laws of inheritance
  • Viruses
  • Endocrine system
  • Nervous system

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


  • Enzymes
  • Plant structure and systems
  • Circulatory system
  • Digestive system
  • Musculoskeletal system
  • Ecological principles

Apart from background knowledge of this content, it’s also important to understand your labs and the basic underlying principles that govern scientific experiments. If you know the ins and outs of experimental design, you’ll earn a lot of points on the exam. I recommend the CliffsNotes AP Biology 4th Edition review book as a helpful resource for going over labs, but you should also look back at what you did in your class. I’ll provide more details on this in the next few sections.

Important Lab Topics Include:

  • Artificial Selection
  • Modeling Evolution
  • Comparing DNA Sequences
  • Diffusion and Osmosis
  • Photosynthesis
  • Cellular Respiration
  • Mitosis and Meiosis
  • Bacterial Transformation
  • Restriction Enzyme Analysis of DNA
  • Energy Dynamics
  • Transpiration
  • Animal Behavior
  • Enzyme Catalysis

Source: https://blog.prepscholar.com/ap-biology-review