In all of Mendel's monohybrid crosses, the F2 plants displayed a 3: 1 ratio of dominant to reces

step 1 In a monohybrid cross, the F2 generation has a 3 to 1 ratio of traits. What proportion of the do

In all of Mendel's monohybrid crosses, the F2 plants...

In all of Mendel's monohybrid crosses, the $\mathrm{F}_{2}$ plants displayed a 3: 1 ratio of dominant to recessive traits. Of those showing the dominant trait, what proportion were true-breeding?
a. $1 / 4$
b. $1 / 3$
c. $2 / 3$
d. None

Key Concepts

Mendelian Inheritance

Mendelian inheritance explains how traits are transmitted from parents to offspring through discrete units called genes. This concept encompasses the laws of segregation and independent assortment, which describe how alleles for a given trait separate and recombine in predictable ways, leading to characteristic ratios in progeny populations.

Monohybrid Cross

A monohybrid cross involves the mating of individuals that differ in the alleles for a single trait. This type of cross allows the examination of how one gene with two alleles, usually one dominant and one recessive, segregates in offspring. It also sets the stage for observing typical Mendelian ratios such as 3:1 in the F2 generation for dominant to recessive phenotypes.

Dominant and Recessive Alleles

This concept refers to the relationship between two alleles where the dominant allele masks the expression of the recessive allele in heterozygous individuals. In Mendelian crosses, dominant alleles determine the phenotype when present, while recessive traits only appear when an individual carries two copies of the recessive allele.

True-Breeding

An organism is considered true-breeding if it is homozygous for a trait, meaning it carries two identical alleles. True-breeding individuals will consistently pass down the same trait to their offspring, making them essential in genetic studies for establishing clear inheritance patterns.

Genotype Versus Phenotype

This key concept distinguishes between the genetic makeup (genotype) of an organism and its physical appearance or expressed traits (phenotype). In scenarios like Mendel's crosses, understanding this difference is crucial, especially since individuals with the dominant phenotype may have different underlying genotypes (either homozygous dominant or heterozygous).

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