Mastering biology Exam Questions and
Answers
In this activity, you will explore how DNA microarrays are being used as a tool for
studying--and possibly treating--cancer.
The data shown here were obtained from a DNA microarray study of gene expression
patterns in 16 cancer patients. Although data for many more genes were obtained from
the DNA microarray, only 12 specific genes of interest are shown.
The data in the chart are color-coded as indicated by the key that appears below the
chart. Red represents high relative gene expression and blue represents low relative
gene expression. - Answer -- A different set of genes is transcribed in cells from patients
in Group I compared to cells from patients in Group II
- For some genes, there is variation in the amount of mRNA present, even among
patients in the same group.
- If you were given microarray data from the cells of a new patient belonging to either
Group I or Group II, you would probably be able to tell which group the patient belongs
to.
All humans carry the same set of genes (although individuals' alleles can vary).
However, different individuals and different cells may have different gene expression
patterns. DNA microarrays reveal differences in these gene expression patterns by
measuring mRNA levels in different cell samples.
In this study, you can see that there are distinct differences in gene expression between
the cells of patients in Group I and Group II. The differences are clear enough that if you
were given microarray data for a new patient, you would probably be able to predict
whether the patient belongs in Group I or Group II. Note, however, that gene expression
patterns are not identical within a single group -- there is variation in gene expression
even among patients within a group.
Group I and Group II correspond to patients with two different kinds of leukemia.
Answers
In this activity, you will explore how DNA microarrays are being used as a tool for
studying--and possibly treating--cancer.
The data shown here were obtained from a DNA microarray study of gene expression
patterns in 16 cancer patients. Although data for many more genes were obtained from
the DNA microarray, only 12 specific genes of interest are shown.
The data in the chart are color-coded as indicated by the key that appears below the
chart. Red represents high relative gene expression and blue represents low relative
gene expression. - Answer -- A different set of genes is transcribed in cells from patients
in Group I compared to cells from patients in Group II
- For some genes, there is variation in the amount of mRNA present, even among
patients in the same group.
- If you were given microarray data from the cells of a new patient belonging to either
Group I or Group II, you would probably be able to tell which group the patient belongs
to.
All humans carry the same set of genes (although individuals' alleles can vary).
However, different individuals and different cells may have different gene expression
patterns. DNA microarrays reveal differences in these gene expression patterns by
measuring mRNA levels in different cell samples.
In this study, you can see that there are distinct differences in gene expression between
the cells of patients in Group I and Group II. The differences are clear enough that if you
were given microarray data for a new patient, you would probably be able to predict
whether the patient belongs in Group I or Group II. Note, however, that gene expression
patterns are not identical within a single group -- there is variation in gene expression
even among patients within a group.
Group I and Group II correspond to patients with two different kinds of leukemia.
