What is Complete Dominance? (Genetics Definition)

definition of complete dominance in genetics

What is Complete Dominance? (Genetics Definition)

In heredity, a scenario emerges when one allele for a gene masks the expression of another allele at the same locus. This phenomenon results in a heterozygous genotype exhibiting the same phenotype as the homozygous dominant genotype. For instance, if a plant with the genotype AA (homozygous dominant) expressing red flowers is crossed with a plant with the genotype aa (homozygous recessive) expressing white flowers, the resulting heterozygous offspring Aa will also express red flowers. The ‘A’ allele exhibits its influence completely, suppressing the effect of the ‘a’ allele.

This concept is foundational to understanding inheritance patterns and predicting phenotypic outcomes in genetic crosses. Its understanding allows researchers and breeders to accurately forecast the traits of offspring, contributing significantly to advancements in agriculture, medicine, and evolutionary biology. Historically, its recognition marked a crucial step in deciphering the complex mechanisms governing the transmission of traits across generations.

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Probability in Genetics: Definition & More

definition of probability in genetics

Probability in Genetics: Definition & More

In the field of inheritance, a mathematical framework predicts the likelihood of specific genotypes and phenotypes arising in offspring. This framework utilizes established principles to quantify the chances of particular genetic outcomes based on the parental genotypes and the mechanisms of allele segregation and recombination during gamete formation. For example, when considering a monohybrid cross involving a single gene with two alleles, the anticipated proportion of heterozygous offspring can be precisely calculated using a Punnett square and the associated principles.

The predictive power afforded by this quantitative approach is crucial for genetic counseling, where individuals can be informed about the risks of inheriting or transmitting specific genetic conditions. Furthermore, it underlies many breeding programs in agriculture and animal husbandry, allowing for informed selection of parent organisms to enhance desirable traits in subsequent generations. Historically, the development of this probabilistic understanding revolutionized genetics, transforming it from a descriptive science into a predictive one, enabling researchers to test hypotheses and develop theories about inheritance patterns.

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