Frq ap bio unit 4 progress check exam
questions & answers 2025/2026
Part 1 A:Describe the first interaction that triggers signaling to begin in a target cell. -
ANSWERSA ligand (or a signaling molecule) binds to a receptor and activates or promotes a
response from the cell. This receptor can either be inside the cell or outside.
*The response indicates that a ligand/chemical receptor, in this case a hormone, binds to a
receptor protein in a target cell.
Part 1 B: Identify a dependent variable in the experimental design. Identify a negative for the
effects of hormone addition. Identify a likely reason why the researchers continued their
experiment for 240 minutes. - ANSWERSThe dependent variable is what was measured, so it's
the level of phosphorylated signaling proteins.
A negative control for the experiment would be to have no hormone present.
The researchers may have wanted to see how long the response to the hormone lasted or they
could have wanted to see the long-term effect.
Part 1 C: Identify the hormone and signaling protein combination that produced the greatest
and most prolonged response. For the STAT5 response that reached 100% at 10 minutes in
Figure 1A, calculate rate the rate of decrease (% decrease per minute) in the detected level of
phosphorylated STAT5 from 10 to 30 minutes. - ANSWERSThe addition of insulin caused high
levels of phosphorylated protein kinase B.
The rate of decrease is around 3%. (100-40=60, 60/20=3)
questions & answers 2025/2026
Part 1 A:Describe the first interaction that triggers signaling to begin in a target cell. -
ANSWERSA ligand (or a signaling molecule) binds to a receptor and activates or promotes a
response from the cell. This receptor can either be inside the cell or outside.
*The response indicates that a ligand/chemical receptor, in this case a hormone, binds to a
receptor protein in a target cell.
Part 1 B: Identify a dependent variable in the experimental design. Identify a negative for the
effects of hormone addition. Identify a likely reason why the researchers continued their
experiment for 240 minutes. - ANSWERSThe dependent variable is what was measured, so it's
the level of phosphorylated signaling proteins.
A negative control for the experiment would be to have no hormone present.
The researchers may have wanted to see how long the response to the hormone lasted or they
could have wanted to see the long-term effect.
Part 1 C: Identify the hormone and signaling protein combination that produced the greatest
and most prolonged response. For the STAT5 response that reached 100% at 10 minutes in
Figure 1A, calculate rate the rate of decrease (% decrease per minute) in the detected level of
phosphorylated STAT5 from 10 to 30 minutes. - ANSWERSThe addition of insulin caused high
levels of phosphorylated protein kinase B.
The rate of decrease is around 3%. (100-40=60, 60/20=3)
