Which method allows for the assessment of genetic variations in a sample?

Electrophoresis is a powerful method used to assess genetic variations by separating nucleic acids or proteins based on their size and charge. This technique allows researchers to visualize genetic differences in a sample, such as variations in DNA sequences (like single nucleotide polymorphisms or SNPs) or the presence of various alleles. By applying an electric field to a gel matrix, DNA fragments migrate at different rates, enabling the identification of distinct genetic patterns among individuals in a population. This is crucial for studies in genetics, forensic analysis, and medical diagnostics, as it provides valuable insights into genetic diversity and relatedness.

The other methods listed have distinct functions but do not focus specifically on assessing genetic variations in the same manner. Polymerase Chain Reaction (PCR) is primarily used to amplify specific DNA sequences, which is foundational in preparing samples for further analysis like electrophoresis. Transcription refers to the process of converting DNA into RNA, playing a role in gene expression but not in assessing genetic variations. Spectrophotometry is used to measure the concentration of nucleic acids and proteins by assessing absorbance, which provides information about quantity rather than genetic diversity. Thus, for the specific purpose of evaluating genetic variations, electrophoresis is the most relevant and effective method.