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Alphabetical Order. Definitions will be exactly what you see. -Justin


an alternative form of a gene


condition in which both alleles for a gene are expressed when present


genetic trait that is expressed when its allele is homozygous or heterozygous

F1 generation

the first offspring from a cross of two varieties in the parental generation

F2 generation

the offspring from the crosses among individuals of the F1 generation


the study of heredity


the genetic makeup of an organism as indicated by its set of alleles


transmission of genetic traits from parent to offspring


refers to an individual with two different alleles for a trait


refers to an individual with two identical alleles for a trait

Incomplete dominance

a condition in which a trait in an individual is intermediate between the phenotype of its two parents

Law of independent assortment

second law of heredity stating that pairs of genes separate independently of one another in meiosis

Law of segregation

the first law of heredity stating that pairs of alleles for a trait separate when gametes are formed

Monohybrid cross

cross involving one pair of contrasting traits

Multiple alleles

the existence of more than two alleles for a genetic trait

P generation (parental generation)

the first two individuals that mate in a genetic cross


family history that shows how a trait is inherited over several generations


observable characteristics of an organism

Polygenic trait

characteristic of an organism that is influenced by several genes


the likelihood that a specific event will occur

Punnett square

diagram used by biologist to predict the probable outcome of a genetic cross


a genetic trait that is not expressed when the contrasting form of the trait is present

Sex-linked trait

a trait that is determined by a gene found on the X chromosome

Test cross

a genetic cross of an individual whose phenotype is dominant but whose genotype is unknown, with a homozygous recessive individual


displaying only one form of a particular trait in offspring

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