In the 1990s, which development allowed the analysis of large populations using molecular techniques?

• A. Development of GIS-based analyses
• B. Application of techniques in molecular biology to large populations
• C. Use of cloud-based data storage to manage big data
• D. Expansion of randomization in clinical trials

Answer: (B)

During the 1990s, the key change was applying molecular biology techniques to study large groups of people. Advances like PCR and later high-throughput genotyping made it feasible to gather and analyze genetic data from thousands or more individuals, turning molecular analysis into a population-level tool. This shift allowed researchers to look for associations between genetic variation and diseases across big cohorts, something not possible with earlier, smaller-scale studies.

Other options don’t capture this shift. GIS-based analyses focus on spatial and environmental data rather than molecular data. Cloud-based storage and computing, while important today, were not the driver for enabling large-scale molecular analyses in that era. Expansion of randomization in clinical trials relates to study design and bias control, not the adoption of molecular techniques for analyzing large populations.