Mendel

Johann Gregor Mendel

A scientist known for his foundational work in genetics and the principles of inheritance.

Model Organism

A non-human species that is extensively studied to understand particular biological phenomena.

Pisum sativum

The scientific name for the garden pea, which Mendel used as his model organism.

Dominant Trait

A trait that is expressed in the phenotype when at least one dominant allele is present.

Recessive Trait

A trait that is only expressed in the phenotype if two copies of the recessive allele are present.

Genotype

The genetic constitution of an organism.

Phenotype

The observable characteristics or traits of an organism.

Law of Segregation

Mendel's law stating that allele pairs separate during gamete formation.

Law of Independent Assortment

Mendel's law that states the inheritance of one trait does not influence the inheritance of another trait.

Homozygous

An organism that has two identical alleles for a particular trait.

Heterozygous

An organism that has two different alleles for a particular trait.

3:1 Ratio

The expected phenotypic ratio of dominant to recessive traits in the F2 generation according to Mendelian genetics.

Incomplete Dominance

A situation in which neither allele is dominant, resulting in a blended phenotype.

Codominance

A relationship between two alleles of a gene, where both are fully expressed in the heterozygote.

X-linked Genes

Genes located on the X chromosome, which exhibit unique inheritance patterns between males and females.

Lethal Alleles

Alleles that can cause the death of an organism when present in a homozygous condition.

Experiments in Plant Hybridization

The title of Mendel's published work that presented his findings on inheritance patterns.

Product Rule

A probability rule stating that the likelihood of two independent events occurring together is the product of their individual probabilities.

Sum Rule

A probability rule stating that the likelihood of either of two mutually exclusive events occurring is the sum of their individual probabilities.