Question 19N.3.HL.TZ0.13
| Date | November 2019 | Marks available | [Maximum mark: 6] | Reference code | 19N.3.HL.TZ0.13 |
| Level | HL | Paper | 3 | Time zone | TZ0 |
| Command term | Explain | Question number | 13 | Adapted from | N/A |
Explain the use of DNA microarrays in genetic testing or diagnosis.
[6]
a. used to test the presence or absence or a gene/allele
OR
used to diagnose the presence of a particular strain of virus/bacteria
OR
used to diagnose the presence of a specific mutation
OR
used to diagnose the presence of an expression of genes ✔
b. DNA spots/probes/sequences attached to solid surface/microarray ✔
c. mRNA from healthy tissue/cell isolated and converted to cDNA
OR
mRNA from cancer tissue/cell isolated and converted to cDNA ✔
d. conversion to cDNA by reverse transcriptase ✔
e. fluorescent dye linked to complementary DNA/cDNA ✔
f. cancer cDNA colored with a different dye from the healthy cDNA ✔ Accept named colour.
g. cDNA binds to/hybridizes with probes «that have complementary base sequences» ✔
h. microarray rinsed to remove cDNA that has not hybridized ✔
i. microarray exposed to laser light which causes dye to give off light ✔
j. fluorescence shows which probes have hybridized
OR
fluorescence shows which sequences were in the tissue/sample ✔
k. hybridized probe shows gene expression
OR
hybridized probe helps in diagnosis of disease ✔
