A PCR product from a STR (short tandem repeat) marker was run on a gel for four individuals. Each allele appears as a distinct band size.
Which individual is homozygous at this locus?
- Acheck_circle
Individual 2 (single 200 bp band)
- B
Individual 4 (250 and 150 bp)
- C
Individual 3 (300 and 100 bp)
- D
Individual 1 (250 and 150 bp)
Explanation
Individual 2 shows only one band (200 bp), indicating both alleles at this locus are the same size. The other three individuals show two bands, indicating heterozygosity.