Question

Fetal DNA is collected and analyzed by Southern blotting. The fetus has a single DNA band that is 1.35 in length. What is the interpretation of this result?

1) The fetus has a normal DNA band
2) The fetus has a DNA band with a deletion
3) The fetus has a DNA band with a duplication
4) The fetus has a DNA band with a mutation

Answer 1

3) The fetus has a DNA band with a duplication.

Step-by-step explanation:

The interpretation of a single DNA band that is 1.35 in length in the fetal DNA analyzed by Southern blotting would be that the fetus has a DNA band with a duplication. This means that there is an extra copy of a section of DNA in the fetus's genome. The extra DNA segment may result in genetic alterations or changes in the fetus's phenotype.