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A researcher used polymerase chain reaction (PCR) to test four individual diploid nematodes for the presence of a mutation in Gene Y. The researcher designed the reaction so that the DNA fragments amplified from wild type and mutant alleles are 350 and 250 base pairs long, respectively.
To identify the genotypes of the individual nematodes, the researcher visualized each PCR result by gel electrophoresis (Figure 1).
Results of a gel electrophoresis shows 5 columns with 5 labeled wells at the top of the columns. Well number 5 is labeled DNA ladder and there are gray lines in the column labeled from top to bottom 1000 bp, 500 bp, 300 bp, 200 bp, and 100 bp. Well 1 is labeled Nematode A and there is a line at approximately 400 bp. Well 2 is labeled Nematode B and there is a line at approximately 250 bp. Well 3 is labeled Nematode C and there is a line at approximately 400 bp and a second line at approximately 250 bp. Well 4 is labeled Nematode D and there is a line at approximately 250 bp.
Figure 1. Gel electrophoresis of Gene Y PCRs in nematodes. The first four lanes contain the PCR product from individual nematodes A-D. Lane 5 contains a DNA ladder for size comparison. The size of each band in the ladder is labeled (bp = base pairs).
Which of the following claims is best supported by the data shown above?
Choose 1 answer: