Development to Cancer Post-test

0 of 20 answered

1. Question 1 of 20

   Two skin cells contain the same pigment gene, but only one cell makes the pigment protein. Which explanation is best?

   The cells regulate expression of the pigment gene differently.The active cell absorbed the finished protein from nearby blood.The two cells must have entirely different chromosome numbers.The inactive cell removed the pigment gene from its DNA.
2. Question 2 of 20

   Two developing palates fail to fuse and look similar. In one, a signal is missing. In the other, cells cannot respond to the signal. What follows?

   The signal must be unrelated because both cases look alike.Two different mechanisms can produce the same visible outcome.The similar appearance proves both cases have the same mutation.The visible outcome identifies which molecular step failed.
3. Question 3 of 20

   Cells already committed to cartilage stop migrating when Signal X is removed. A different motility signal restores migration, and the cells still become cartilage. What role did Signal X most likely play?

   It permitted the migration, and did not set cartilage identity.It served only as a structural part of the cartilage.It permanently changed every gene in the cells.It instructed cartilage identity and nothing else.
4. Question 4 of 20

   A cell still contains a working growth-brake gene, but regulatory proteins keep the gene silent. Which statement is most accurate?

   The brake gene is still present but is repressed.The brake protein must be present at a high level.The brake gene has become an oncogene.The cell deleted the brake gene from every chromosome.
5. Question 5 of 20

   One cell line activates a growth pathway. Another loses a stop signal. Both divide too often. Which principle fits best?

   Only the activated growth pathway can produce excess division.Different disrupted pathways can converge on the same outcome.A stop signal and a growth signal are always the same molecule.The two cell lines must contain identical mutations.
6. Question 6 of 20

   What is differentiation?

   A cell replaces its DNA with genes from a nearby tissue.A tissue spreads from its original site to a distant organ.A cell develops a specialized identity through gene regulation.A cell divides without any checkpoint or external signal.
7. Question 7 of 20

   During normal development, cells between forming fingers undergo programmed death. What does this show?

   Development can sculpt tissue through programmed cell removal.Development builds structures only by adding more cells.The cells died because every developmental signal failed.Programmed death is evidence that the embryo has cancer.
8. Question 8 of 20

   Tumor cells reduce adhesion and move through a remodeled extracellular matrix into nearby tissue. What does this evidence support?

   The cells formed a benign tumor that cannot invade.The cells completed metastasis to a distant organ.The cells changed every gene into an oncogene.These cells support a claim of local tissue invasion.
9. Question 9 of 20

   The same signal promotes cell division early in development but promotes differentiation later. Which explanation is best?

   The later cells must no longer contain receptors or genes.A signal has one fixed effect in every cell and at every time.The timing and the cell's context can change the response.The early and late signals cannot be the same molecule.
10. Question 10 of 20

    Which description best defines cancer?

    Any group of cells that divides faster than nearby tissue.Any tumor that can be seen in a medical image.An inherited condition that always appears in every family member.Diseases with lost growth control and possible invasion or spread.
11. Question 11 of 20

    A biopsy shows abnormal cells crossing into nearby tissue. No distant sites were tested. Which conclusion stays within the evidence?

    The tumor is benign because no distant tumor was measured.The biopsy proves which treatment will work best.The cancer has metastasized to every major organ.The tumor is invasive, and metastasis remains unproven.
12. Question 12 of 20

    A targeted drug kills most cells in a tumor, but a small cell group lacks the target and survives. What is the best prediction?

    The surviving cells will automatically become normal tissue.The resistant group of cells may expand after treatment begins.The drug will add the missing target to every surviving cell.All tumor cells will remain equally sensitive to the drug.
13. Question 13 of 20

    A team changes matrix stiffness and records how far tumor cells move. Which measurement is the dependent variable?

    The distance the cells moveThe type of culture plateThe research questionThe chosen stiffness settings
14. Question 14 of 20

    Researchers test a receptor-blocking drug. Which group is the best negative control?

    Cells treated with the strongest drug doseVehicle-treated cells without the drugCells selected after they become resistantCells with every receptor removed
15. Question 15 of 20

    A drug reduces tumor-cell division in one culture model. Which claim is supported?

    The drug prevents all future resistance.The drug cures every cancer in a whole person.The culture result proves the tumor was inherited.The drug reduced division in this culture model.
16. Question 16 of 20

    Two gene disruptions produce similar craniofacial changes in zebrafish. What is the best next step?

    Declare that both fish have the same human syndrome.Assume both disruptions change every tissue equally.Ignore the result because zebrafish are not human.Test whether both genes affect one developmental pathway.
17. Question 17 of 20

    Gene S DNA is present, its RNA is low, and its protein is low. Which test most directly checks transcriptional regulation?

    Count all cells without measuring Gene SAssume Gene S was removed from the genomeMeasure Gene S RNA after changing the regulatorMeasure an unrelated protein in a different tissue
18. Question 18 of 20

    Replicate cell counts vary widely with no consistent direction. Which response best improves the measurement?

    Keep only the largest countCall the variation proof of metastasisCalibrate and add controlled replicatesReplace all counts with the expected value
19. Question 19 of 20

    Which statement correctly distinguishes infection from cancer?

    Every infection produces a malignant tumor.Cancer cells pass between people through ordinary respiratory droplets.Some infections raise risk; cancer is generally not contagious.Cancer is always caused by a pathogen.
20. Question 20 of 20

    A family has a pathogenic cancer-risk variant, but not every carrier develops cancer. What explains this pattern?

    Only noncarriers can develop cancer.The variant acts with other genetic, environmental, and chance factors.The variant means metastatic cancer is already present in every carrier.A carrier develops cancer only after a biopsy.