Question

For the microsatellite marker D13S1699 the patient and a healthy control are _____ because there is only one band corresponding to one PCR product.

1) homozygous
2) heterozygous
3) not related
4) cannot be determined

Answer 1

The patient and a healthy control displaying one band for the microsatellite marker D13S1699 are homozygous, meaning they have identical alleles for that microsatellite region.

Step-by-step explanation:

For the microsatellite marker D13S1699, if the patient and a healthy control show only one band corresponding to one PCR product, they are homozygous for that particular marker. This indicates that both alleles for that microsatellite region are identical.

In the context of genetic testing, observing the number of bands present on an electrophoresis gel can determine whether individuals are homozygous, where one band appears indicating identical alleles, or heterozygous, where two bands would indicate two different alleles. For genetic diseases like sickle-cell anemia, this type of analysis helps in determining carriers and those affected by the mutation.