Final answer:
The term for crosses between parents that differ in only one trait is a monohybrid cross. This involves crossings between true-breeding parents for a single contrasting trait, resulting in monohybrid offspring.
Step-by-step explanation:
The term for crosses between parents that differ in only one trait is a monohybrid cross. This concept was pioneered by Gregor Mendel, who performed experiments using pea plants to understand the principles of inheritance. A monohybrid cross involves parents that are true-breeding for contrasting traits of a single characteristic. When these parents are crossed, their offspring, known as monohybrids, inherit one allele from each parent. Mendel's experiments showed that the F1 generation exhibited the phenotype of one parent, and the resulting F2 generation exhibited a phenotypic ratio of approximately 3:1. A common tool used to predict the outcome of a monohybrid cross is the Punnett Square, which showcases the possible genetic combinations of the offspring.
It's important to distinguish a monohybrid cross from a test cross, which is used to determine if an individual with a dominant phenotype is homozygous dominant or heterozygous. In a test cross, an individual with a dominant phenotype is crossed with a homozygous recessive individual, resulting in a characteristic 1:1 phenotypic ratio if the dominant individual is heterozygous.
The correct term for a cross between parents differing in only one trait is a monohybrid cross. Monohybrid crosses are instrumental in predicting the inheritance of single traits, as demonstrated by Mendel's classic genetic experiments with pea plants.