Heredity Flashcards
Gregor Mendel
Father of Genetics
Trait
An expressed characteristic
Genes
Hereditary factors that determine traits
Locus
The position of a gene on a chromosome
Allele
Alternate form of the same gene
Dominant Allele
An allele that will always be expressed in spite of the presence of a recessive trait
Recessive Allele
An allele that will only be expressed when there is another recessive trait
Homozygous
The organism has two identical alleles for the same trait
Heterozygous
The organism has different alleles for the same trait, but only the Dominant Allele is expressed
Phenotype
The physical appearance of an organism
Genotype
The genetic makeup of an organism
P1 Generation
The parent generation in an experiment
F1 Generation
The offspring of the P1 Generation
F2 Generation
The offspring of the F1 Generation and grandoffspring of the P1 Generation
Principles of Genetics
- Law of Dominance
- Law of Segregation
- Law of Independent Assortment
Law of Dominance
The Dominant Allele will always be expressed when crossing a true-breeding dominant organism and true-breeding recessive organism
Monohybrid Cross
Only one trait is being studied
Punnett Square
Used to predict the outcome of hypothetical crosses between two organisms
Law of Segregation
All genotypes that could result from a cross are possible
Law of Independent Assortment
Each trait is crossed independently and all genotypes for each trait are possible
Dihybrid Cross
Two traits are being studied
Test Cross
A way to determine a genotype of one of the parents
Incomplete Dominance
Traits will blend
Codominance
Equal expression of both alleles
