Released AP Bio 2025 Q1

Which words should a student have learned already in order to understand the introduction to question 1?

Describe the function of ribosomes

Identify the dependent variable in the experiment shown in Figure 1.

Justify why the researchers included the control of measuring the relative amounts of both Sec62 and SR proteins in cells that were treated with Sec62 siRNA only (data shown in Figure 1).

Based on Figure 1, describe the effect on the production of SR protein when cells are treated with Sec62 siRNA.

Identify the independent variable in the researchers’ second experiment (data shown in

Figure 2).

Based on Figure 2, identify the protein(s) that when treated with Sec62 siRNA showed an increase in percent transport to the ER compared with the control.

Protein 1 is encoded by 234 nucleotides, while protein 2 is encoded by 495 nucleotides. Assuming all nucleotides for both proteins encode amino acids, calculate the difference in the number of amino acids between the two proteins.

Researchers claim that protein 1 is the only tested protein that is transported to the ER following its complete translation in the cytosol. Using data from Figure 2, support the researchers’ claim.

For any protein that enters the ER, researchers claim that amino acids close to the protein’s amino terminus determine how likely the protein is to pass through the protein channel within the ER membrane. Justify the researchers’ claim based on your understanding of factors that affect the transport of proteins across membranes.