2023 AP Biology FRQ Answers by Mrs. Jones

2023 AP Biology FRQ Answers by Mrs. Jones

Mrs. Jones’ responses to the 2023 AP Biology Free Response Questions provide detailed answers for students preparing for the exam. The document covers key topics such as cellular processes, gene expression, and ecological interactions, offering insights into complex biological concepts. Ideal for AP Biology students, these responses serve as a study aid to understand the application of biological principles in various scenarios. Each answer is structured to reflect the expectations of the AP exam, ensuring alignment with the curriculum and exam format.

Key Points

  • Includes comprehensive answers to 2023 AP Biology FRQs
  • Explains key biological concepts like phosphorylation and gene regulation
  • Covers ecological interactions and their impact on biodiversity
  • Discusses cellular respiration and the role of mitochondria
  • Analyzes the relationship between CO2 levels and mitochondrial function
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  • Aliusa
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Mrs. Jones’ Responses to the 2023 FRQ
Disclaimer: The following responses are the answers that I
would have written if I was taking the exam. I am adding
some extra information into the answers to do some
explanation that might not be needed on those questions. I
DO NOT have any insider knowledge as to these questions
nor to their scoring guidelines. The scoring guidelines will
not be released to the public until September
(traditionally).
In addition, I am human so there might be information that
should be included that isn’t included
(or I might be wrong about answers).
The FRQs prompts are not included in this document. If you
would like to see the full FRQs, please refer to:
https://apcentral.collegeboard.org/media/pdf/ap23-frq-
biology.pdf
AP Biology 2023 Mrs. Jones’ Responses # 1
The addition of a phosphate group to a protein could cause the protein to have a conformational
shape change. Due to this shape change, the protein can go from an active to an inactive form.
During the process of a phosphorylation cascade, the intermediates that are activated will
phosphorylate additional components in the pathway which will also activate additional
components. For example, the activated receptor protein will activate one protein kinase A, this
protein kinase A will activate 10 intermediate proteins, then those 10 intermediate proteins will
activate 10 each of their target intermediate. As you see this signal is being amplified.
The dependent variable is the variable that is measured due to the independent variable. The
researchers changed the type of mutation (WT, pho81mt, pho4mt) in the yeast strains, which is
the independent variable. The researchers measured the activity of the APase enzyme and the
amount of mRNA for PHO1 that encodes the APase enzyme, which are the dependent variables.
The researchers used the wild-type (WT) strain as a negative control. This allows the researchers
to establish a baseline of the levels of APase and amount of PHO1 mRNA in each environment
(without the treatment) to compare with the treatment groups to determine the effect of Pho81
and Pho4 on the activation of the target genes.
ADDED: The wild-type has all of the genes for the PHO genes. By using the wild-type, you are able to
ensure the gene with the mutation is the one being tested.
By using a specific mutant, the researchers are able to isolate each protein on the overall pathway
to see the specific function of each. Pho81 inhibits Pho80/Pho85 so the Pho4 is not
phosphorylated, so if this process was inhibited by a mutant Pho81 in low-phosphate environment.
Pho4 interacts with the DNA as a transcription factor, so if the Pho4 was non-functional.
The yeast strain with the highest relative amount of PHO1 mRNA was the wild-type in Low-P
i
environment. This strain has 10 +/- 2.0 (so 8.0 – 12.0) which does not overlap any of the other
values and is the highest.
% 𝑐ℎ𝑎𝑛𝑔𝑒 =
𝑓𝑖𝑛𝑎𝑙 − 𝑖𝑛𝑖𝑡𝑖𝑎𝑙
𝑖𝑛𝑖𝑡𝑖𝑎𝑙
𝑥100 =
0.5 − 17.3
17.3
𝑥100 =
−16.8
17.3
𝑥100 = −97.1%
There is a decrease of 97.1% between the low P
i
and high P
i
in the wild-type strain.
If the Pho85 protein is nonfunctional, then it would not be able to complex with Pho80 to activate
the Pho4. Traditionally, the phosphorylation of Pho4 leads to no transcription of the PHO1 gene
(low levels of mRNA). Due to the mutation, the Pho4 is not phosphorylated so as seen in the low-
phosphate environment the Pho4 will activate the transcription of PHO1 gene so expression will
increase. There will be more mRNA synthesized (leading to more APase activity).
Pho85 is unable to phosphorylate Pho4 leading to inducing expression of the target genes PHO1.
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End of Document
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Faqs of 2023 AP Biology FRQ Answers by Mrs. Jones
What are the key themes in Mrs. Jones' AP Biology responses?
Mrs. Jones' responses focus on critical themes such as cellular processes, gene regulation, and ecological interactions. Each answer delves into specific biological mechanisms, like phosphorylation cascades and their effects on protein function. The responses also highlight the importance of biodiversity in ecosystems and the physiological adaptations of organisms to environmental changes. These themes are essential for understanding the complexities of biology as outlined in the AP curriculum.
How does phosphorylation affect protein function according to the responses?
Phosphorylation is a key regulatory mechanism that alters protein conformation and activity. In Mrs. Jones' responses, it is explained that the addition of a phosphate group can convert proteins from inactive to active forms, influencing various cellular pathways. This process is crucial in signal transduction, where activated proteins can trigger cascades that amplify cellular responses. Understanding this mechanism is vital for AP Biology students as it illustrates how cells communicate and respond to their environment.
What role does the inner mitochondrial membrane play in cellular respiration?
The inner mitochondrial membrane is essential for oxidative phosphorylation, a critical stage in cellular respiration. According to Mrs. Jones' responses, this membrane houses the electron transport chain, where NADH and FADH2 are oxidized to generate a proton gradient. This gradient drives ATP synthesis via ATP synthase, highlighting the membrane's role as both a barrier and a site for energy production. Understanding this process is fundamental for AP Biology students studying cellular energetics.
What is the significance of biodiversity in ecosystems as discussed in the responses?
Biodiversity enhances ecosystem resilience, allowing for multiple interactions among species. Mrs. Jones emphasizes that a diverse range of primary producers can buffer against the loss of any single species, maintaining stability in higher trophic levels. This concept is crucial for understanding ecological dynamics and the importance of conservation efforts. Students preparing for the AP exam should grasp how biodiversity contributes to ecosystem health and functionality.
How does elevated CO2 affect mitochondrial function according to the document?
The responses indicate that elevated CO2 levels lead to an increase in the number of mitochondria in plant cells. This adaptation is linked to enhanced cellular respiration and energy production, allowing plants to thrive in changing environments. Mrs. Jones explains that this relationship underscores the significance of environmental factors in gene expression and organelle replication. Understanding this connection is vital for AP Biology students exploring the impact of climate change on plant physiology.