The ability to taste the bitter compound phenylthiocarbamide (PTC) is an autosomal dominant trait. The inability to taste PTC is a recessive condition. In a sample of 500 people, 360 have the ability to taste PTC and 140 do not. Calculate the frequency of each genotype

Key Concepts

Autosomal Dominance and Recessiveness

In genetics, traits can be classified as dominant or recessive based on how they are expressed in an organism. An autosomal dominant trait, like the ability to taste PTC, requires only one copy of the dominant allele for expression, while a recessive trait requires two copies of the recessive allele. This distinction is crucial for understanding inheritance patterns and predicting genotype frequencies.

Hardy-Weinberg Principle

The Hardy-Weinberg principle provides a mathematical framework for understanding allele and genotype frequencies in a population under ideal conditions. It states that allele frequencies will remain constant from generation to generation in the absence of evolutionary influences. This principle is essential for calculating expected genotype frequencies based on observed phenotypic ratios.

Genotype Frequency Calculation

Genotype frequency refers to the proportion of different genotypes in a population. To calculate these frequencies, one can use the observed phenotypic data along with the Hardy-Weinberg equations. For the PTC tasting trait, knowing the number of tasters and non-tasters allows for the determination of the frequencies of the homozygous dominant, heterozygous, and homozygous recessive genotypes.