The multiplication method is best used to determine what?

• A. Genomic sequences
• B. Probabilities in simple traits
• C. Phenotypic frequencies in complex traits
• D. Number of chromosomes in a species

Answer: (B)

The multiplication method is best known for calculating the probabilities of independent events occurring in genetics, particularly in the context of simple traits. When examining traits that are governed by single genes, the multiplication rule states that the probability of two independent events both occurring is the product of their individual probabilities. For example, when considering a monohybrid cross, if one parent is homozygous dominant and the other is homozygous recessive, the probability of producing offspring with a specific genotype can be calculated using this method.

This approach is particularly effective when dealing with simple Mendelian traits where the inheritance pattern is straightforward, making it a practical tool for predicting the likelihood of certain traits appearing in offspring. Understanding this mechanism enables one to approach genetic problems systematically, calculating expected genotypic and phenotypic ratios from parental crosses.

In contrast, the other options involve complexities that do not neatly align with the multiplication method. Genomic sequences require methodologies more aligned with molecular biology rather than probabilistic calculations. Phenotypic frequencies in complex traits often involve polygenic inheritance, which complicates the simple application of the multiplication rule. Finally, counting chromosomes in a species doesn't pertain to calculating probabilities but rather involves cytological techniques. Thus, the multiplication method's focus on independent events aligns