Humber Admissions Practice Test

What is the purpose of genetic crosses or Punnett squares?

1. To determine an organism's mutation rate

2. To predict the phenotype and genotype of offspring

3. To identify the presence of dominant traits

4. To crossbreed different species

The correct answer is: To predict the phenotype and genotype of offspring

The purpose of genetic crosses or Punnett squares is to predict the phenotype and genotype of offspring resulting from a particular pairing of organisms. This tool allows geneticists to visualize and calculate the potential genetic outcomes when two organisms breed, providing insights into the inherited traits based on the alleles present in the parents. By analyzing specific alleles, one can determine the likelihood of offspring exhibiting certain traits, whether dominant or recessive. This predictive capability is fundamental in genetics, especially in breeding experiments and studying inheritance patterns. While determining an organism's mutation rate, identifying dominant traits, and crossbreeding different species are important aspects of genetics, they do not directly relate to the primary function of Punnett squares, which specifically focuses on offspring probabilities in a genetic cross.