Question

When interpreting DNA microarray analysis and comparing two genes, an active gene will be detected

a) as having a brighter signal due to the presence of a many more molecules of mRNA.
b) as having a brighter signal due to the presence of lower amounts cDNA after reverse transcription.
c) as having a dimmer signal due to the presence of high amounts of cDNA after reverse transcription.
d) as having a brighter signal due to the presence of less molecules of mRNA.

Answer 1

In DNA microarray analysis, an active gene is indicated by a brighter signal, which is a result of a higher amount of mRNA being present and reverse-transcribed to cDNA.

Step-by-step explanation:

When interpreting DNA microarray analysis and comparing two genes, an active gene will be detected as a) having a brighter signal due to the presence of many more molecules of mRNA. This is because during the microarray process, mRNA is isolated and reverse-transcribed to cDNA. The cDNA is then labeled with fluorescent dyes and hybridized to the microarray chip. The intensity of the fluorescence at each spot on the chip indicates the quantity of cDNA bound, which is proportional to the amount of the original mRNA in the sample. Therefore, a brighter signal signifies higher gene activity and more mRNA molecules that have been reverse-transcribed.