Reviewing the 2021 AP Biology FRQ Exam - Administration #1

Mr. Chow, an AP Biology teacher, introduces his video on reviewing the 2021 AP Biology Free Response Questions (FRQs) from the in-person exam administered on May 14, 2021. He emphasizes the video's utility for all students, not just his own, and mentions that his students will use it to review for their online AP test. The scoring guidelines are pending, and the provided answers are his own, vetted with the help of 14 students. He encourages feedback in the comments and provides timestamps for different sections of the exam review.

The video discusses the format of the online AP Biology test, which mirrors the in-person version but without the requirement to graph or draw. Mr. Chow outlines the pros and cons of taking the test online, such as the ability to type faster and edit responses, against not being able to go back and change answers and the potential distractions of testing in a home environment. He also clarifies that while the online test won't require graphing, understanding these skills is still essential.

Mr. Chow provides an in-depth breakdown of the timing strategy for the FRQ section, emphasizing the importance of pacing and not rushing through questions. He shares his experience of taking the exam and the timing issues he encountered. The video also covers what AP graders look for in responses, the possibility of multiple correct answers, and the reality that achieving a perfect score is highly unlikely and not necessary to pass the exam.

The video delves into the first FRQ about polycystic kidney disease (PKD), its genetic mutation, and the role of the sodium-potassium pump in ATPase activity. It discusses the experimental approach to understanding the disease's impact and the importance of understanding the question's context before attempting to answer. Mr. Chow demonstrates his note-taking strategy to grasp the question's requirements efficiently.

This section focuses on explaining why ATP is necessary for the sodium-potassium ATPase activity. Mr. Chow clarifies the concept of active transport and how ATP provides the energy required to move sodium and potassium ions against their concentration gradient. He also offers encouragement and advice for students to stick with the course material and not to be overwhelmed by the complexity of the subject.

The video script outlines how to identify dependent variables in an experiment, using Figure 1 as a reference. It also discusses the rationale behind using normal human kidney cells as a control and the importance of a range of concentrations in the experiment. Mr. Chow emphasizes the need for clear, professional writing in AP responses and the importance of saving time for each FRQ.

The focus shifts to the second FRQ, which investigates a genetic disorder affecting glucose metabolism. Mr. Chow explains the importance of understanding glucose's role in cellular respiration and ATP production. He provides a detailed analysis of the pedigree chart and how it can be used to determine the inheritance pattern of the disorder, highlighting the clues provided by the data and the conclusions that can be drawn from them.

In this section, Mr. Chow discusses the third FRQ, which explores the hypothesis that resveratrol, a plant compound, improves mitochondrial function. He explains the experimental setup, including the use of mammalian muscle cells and glucose, and the measurement of ATP production. The video also covers the advantages of aerobic respiration over fermentation and the concept of a negative control in experiments.

The fourth FRQ reviewed in the video concerns the evolution and natural selection observed in finch beak adaptations. Mr. Chow describes the hybridization of two finch species and the resulting 'Big Bird' lineage. He discusses the concept of reproductive isolation and how differences in beak shapes and sizes relate to the birds' ability to consume different food types, emphasizing the significance of these adaptations in the context of survival and reproduction.

This section of the video examines the fifth FRQ, which studies the life cycle of annual plants, specifically the giant ragweed, an invasive species. Mr. Chow explores the impact of invasive species on biodiversity and the ecological effects of removing such species from an ecosystem. He also discusses the concept of logistic growth in plant populations and how factors like plowing can influence this growth pattern.

The final FRQ reviewed focuses on the adaptation of a krill species to increasing water temperatures. Mr. Chow explains the role of heat shock proteins (HSPs) and their encoding genes in protecting the krill from protein misfolding due to higher temperatures. The video outlines the experimental setup to test the expression of HSP genes and how the data supports the hypothesis that certain HSPs are more effective in refolding proteins. It also touches on the process of alternative splicing in gene expression.