AP® Biology Exam readers identified some broad content areas that presented difficulties for students.

• Students are still having difficulty with statistics and understanding how to interpret this data.
• Students struggle with the central dogma of biology—understanding the processes of transcription and translation. They had difficulty merging Mendelian and molecular genetics. Modeling the processes may help students gain a better framework. You may also wish to use transformation to show how changes in DNA can lead to changes in proteins. 

• Photosynthesis and cellular respiration were also areas in which students need more work. Some students were unable to identify them as metabolic processes.
• Quantitative ecology was also an area in which students struggled. You may wish to review the Hardy-Weinberg equilibrium, making sure that students are getting a conceptual understanding in addition to just learning the equation. Students also need help understanding how to deal with populations that are not in the Hardy-Weinberg equilibrium. You may wish to use a short activity on teaching Hardy-Weinberg to get the conversation started.

AP® Chemistry Exam readers identified some broad content areas that presented difficulties for students.

• Content mastery was lacking, and applying content to a novel situation presented a problem.
• Many students mixed up intramolecular forces and intermolecular forces. Also, students often used van der Waals forces incorrectly. 

• Students had difficulty with the general concept of kinetics and had particular difficulty determining rate order. Consider using the Iodine Clock Reaction Kit  as an introduction to reaction rates. For more practice determining rate order, try our Chemical Kinetics Kit.

• Equilibrium in general was difficult for students. The use of the Henderson-Hasselbalch equation with an explanation of buffers did not yield very high scores.

AP® Environmental Science Exam readers identified some broad content areas that presented difficulties for students.

• Students did not correctly describe how ecosystem services provided a benefit to people.
• Students were often North American-centric in their examples and understandings. It was expressed that students should have experiences with international examples.

• It was recommended that students be up to date with current events. Some of the events mentioned include ocean acidification, oil spills, tsunamis, hydraulic fracturing (fracking), and others.
• Students had misconceptions about how some alternative energy resources work. For example, some students associated hydroelectric power with steam turbines. The Carolina STEM Challenge®: Emerging Energies series allows students to have hands-on experiences with modeling alternative energy.

• Students need help in developing an understanding of the general principles of evolution. Students had difficulties with species concepts, speciation mechanisms, and how to increase biodiversity. A better foundation in natural selection, biodiversity, and loss of biodiversity might help some students. 

• Some students were unable to differentiate between climate change and ozone depletion.

AP® Physics Exams readers identified some broad content areas that presented difficulties for students taking either the Physics 1 or Physics 2 exam.

• In Physics 1, students score lowest on energy and kinematics.

• In Physics 2, students score lowest on electrostatics. They did not present a well-written explanation of the situation presented in the problem.
• Students need practice sketching accurate free body diagrams for application and justification in problem solving.

• Momentum with vector analysis proved difficult.

• While students scored well on the optics question, additional explanation with ray diagrams would have benefited students. “Mirror Mirror” is a quick activity to introduce reflection and ray diagrams. For a cross-curricular activity, take a look at “Optics of the Human Eye.”