FRQS test questions well answered
(A+ rated)
(i) Chemical Z moves by facilitated diffusion through the plasma membrane
(ii) there will be twice as much DNA per cell in cells that are (at the end of S and) in G2 than in
cells that are in G1 because DNA replication occurs during S phase - correct answer ✔✔FRQ 1
(a)
Chemical Z is a large, polar molecule. Describe the process by which chemical Z moves across
the plasma membrane without an input of cellular energy. Explain why the amount of DNA in a
cell indicates whether the cell is in G1, S, or G2.
(i) Percent of T cells (in each phase of the cell cycle/interphase)
(ii) the use of untreated cells in the experiment provides a control to see the percent of cells in
each phase of the cell cycle in an absence of chemicals/chemical Z
(iii) the use of both Chemicals B and C in the experiment shows the percent of cells in each
phase when blocked by chemical B(in S) and by chemical C(in G2) in order to help interpret the
data from cells treated with chemical Z - correct answer ✔✔FRQ 1 (b)
Identify a dependent variable in the experiment. Justify the use of untreated cells in the
experiment. Justify the use of both chemicals B and C in the experiment
(i) G1
(ii) In comparison with the untreated T cells, a greater percent of the cells treated with chemical
Z is in G1
(iii) (70% * 600)-(50% * 600)=120 cells - correct answer ✔✔FRQ 1 (c)
Based on the data in Figure 2, identify the phase in interphase at which chemical Z treatment
blocks the cell cycle. Describe the trends in the data that support your identification. Based on
the mean values shown in Figure 2, calculate the difference in the number of cells in G1
between the sample treated with chemical Z and the untreated sample if a total of 600 cells are
counted for each sample.
, (i) There will be no difference between the cell cycle of untreated cancerous T cells and the cell
cycle of(cancerous) T cells treated with chemical Z
(ii) chemical Z can have a negative effect because chemical Z will also prevent cell division of
normal T cells, which interferes with the ability of normal T cells to respond to an infection
efficiently - correct answer ✔✔FRQ 1 (d)
Cancerous T cells result from genetic mutations and lack normal cell cycle controls. Scientists
tested whether chemical Z blocks the cell cycle of cancerous T cells. State the null hypothesis for
their experiment. Individuals with cancerous T cells also have normal T cells. Scientists find that
chemical Z is an effective treatment against cancerous T cells. However, they claim that using
chemical Z can have a negative effect on a patient's ability to fight off an infection. Provide
reasoning to justify their claim.
(i) the Sev RTK on the R7 precursor cells binds with Boss on the R8 cell - correct answer ✔✔FRQ
2 (a)
Describe the first interaction that must occur between the R7 precursor cell and the R8 Cell for
the R7 precursor to differentiate to an R7 photoreceptor cell.
(i) Due to the change in shape, Ras can no longer bind to the intracellular portion of the Sev RTK
and become active, thus Ras is not able to induce the intracellular signaling that allows the R7
precursor to become a photoreceptor cell. - correct answer ✔✔FRQ 2 (b)
Describe how the defect in the Single-Mutant (Sev-) R7 precursor cell causes the cell to become
a cone cell instead of a photoreceptor cell.
(i) Their prediction is likely correct bc in the wild-type forms of R8 cells and R7 precursor cells
the intracellular signaling that allows the latter to become photoreceptor cells is caused by an
actived Ras protein. This activation requites the interactiosn between a Sev RTK bound
externally to a Boss protein, but in the Double Mutant form RasD is already active. - correct
answer ✔✔FRQ 2 (c)
The scientists predict that the presence of activated Ras in the Double-Mutant (Sev-RasD) R7
precursor cell will enable the cell to differentiate into an R7 photoreceptor cell. Based on Figure
1, evaluate the likely accuracy of their prediction.
(A+ rated)
(i) Chemical Z moves by facilitated diffusion through the plasma membrane
(ii) there will be twice as much DNA per cell in cells that are (at the end of S and) in G2 than in
cells that are in G1 because DNA replication occurs during S phase - correct answer ✔✔FRQ 1
(a)
Chemical Z is a large, polar molecule. Describe the process by which chemical Z moves across
the plasma membrane without an input of cellular energy. Explain why the amount of DNA in a
cell indicates whether the cell is in G1, S, or G2.
(i) Percent of T cells (in each phase of the cell cycle/interphase)
(ii) the use of untreated cells in the experiment provides a control to see the percent of cells in
each phase of the cell cycle in an absence of chemicals/chemical Z
(iii) the use of both Chemicals B and C in the experiment shows the percent of cells in each
phase when blocked by chemical B(in S) and by chemical C(in G2) in order to help interpret the
data from cells treated with chemical Z - correct answer ✔✔FRQ 1 (b)
Identify a dependent variable in the experiment. Justify the use of untreated cells in the
experiment. Justify the use of both chemicals B and C in the experiment
(i) G1
(ii) In comparison with the untreated T cells, a greater percent of the cells treated with chemical
Z is in G1
(iii) (70% * 600)-(50% * 600)=120 cells - correct answer ✔✔FRQ 1 (c)
Based on the data in Figure 2, identify the phase in interphase at which chemical Z treatment
blocks the cell cycle. Describe the trends in the data that support your identification. Based on
the mean values shown in Figure 2, calculate the difference in the number of cells in G1
between the sample treated with chemical Z and the untreated sample if a total of 600 cells are
counted for each sample.
, (i) There will be no difference between the cell cycle of untreated cancerous T cells and the cell
cycle of(cancerous) T cells treated with chemical Z
(ii) chemical Z can have a negative effect because chemical Z will also prevent cell division of
normal T cells, which interferes with the ability of normal T cells to respond to an infection
efficiently - correct answer ✔✔FRQ 1 (d)
Cancerous T cells result from genetic mutations and lack normal cell cycle controls. Scientists
tested whether chemical Z blocks the cell cycle of cancerous T cells. State the null hypothesis for
their experiment. Individuals with cancerous T cells also have normal T cells. Scientists find that
chemical Z is an effective treatment against cancerous T cells. However, they claim that using
chemical Z can have a negative effect on a patient's ability to fight off an infection. Provide
reasoning to justify their claim.
(i) the Sev RTK on the R7 precursor cells binds with Boss on the R8 cell - correct answer ✔✔FRQ
2 (a)
Describe the first interaction that must occur between the R7 precursor cell and the R8 Cell for
the R7 precursor to differentiate to an R7 photoreceptor cell.
(i) Due to the change in shape, Ras can no longer bind to the intracellular portion of the Sev RTK
and become active, thus Ras is not able to induce the intracellular signaling that allows the R7
precursor to become a photoreceptor cell. - correct answer ✔✔FRQ 2 (b)
Describe how the defect in the Single-Mutant (Sev-) R7 precursor cell causes the cell to become
a cone cell instead of a photoreceptor cell.
(i) Their prediction is likely correct bc in the wild-type forms of R8 cells and R7 precursor cells
the intracellular signaling that allows the latter to become photoreceptor cells is caused by an
actived Ras protein. This activation requites the interactiosn between a Sev RTK bound
externally to a Boss protein, but in the Double Mutant form RasD is already active. - correct
answer ✔✔FRQ 2 (c)
The scientists predict that the presence of activated Ras in the Double-Mutant (Sev-RasD) R7
precursor cell will enable the cell to differentiate into an R7 photoreceptor cell. Based on Figure
1, evaluate the likely accuracy of their prediction.
