Gene- factors that control a trait
Alleles- the different forms of a gene
Heredity- passing of a physical characteristics from parents to offspring
Genetics- scientific study of heredity
Trait- Special characteristics (ex. Color, seed, shape)
Pure bread- Same version of a trait as many generations before. (Offspring have the same trait)
Hybrid- has two different forms of alleles for a trait
Homozygous- an organism that has 2 identical alleles
Heterozygous- an organism that has 2 different alleles
Genotype- the genetic makeup, allele combination
Phenotype- the physical appearance, or observable trait
Ex. A plant can have the phenotype for tall, but the genotype could be Tt or TT
Dominant TT, Tt
Recessive tt
T T
t Tt Tt
t Tt Tt
100% tall
T t
T TT Tt
t Tt tt
75% tall, 25% short
Dominant allele- the organism will automatically inherit the dominant form of the trait. DD, Dd
Recessive alleles- hide or are masked when a dominant allele is present.
To get the recessive form of a trait, there must be two of the recessive alleles. Dd
Codominance- the alleles are neither dominant nor recessive
Both alleles are expressed in the offspring
