A Researcher Is Studying a Metabolic Disorder

Multiple Choice

A researcher is studying a metabolic disorder.To identify the gene or genes linked with the disorder's phenotype, he compares the chromosomal DNA of normal volunteers and clinical patients.Despite a great deal of work, he is unable to identify a gene.Another research group, however, reports a gene.Which of the following may account for the researcher's experimental failure?

A) He analyzed too much DNA.
B) He should have only looked at the DNA of patients.
C) He did not analyze all of the genes found in a human cell.
D) He did not include chloroplast DNA.
E) Genes cannot be identified using this method.