Genetics Flashcards
Definition “Alleles, genes”
Gene - DNA sequences of hundreds to thousands of base pairs that contain the “instructions” for making a protein are called “Genes”
Allele - Different versions of the same gene are called “Alleles” because their sequences are different.
Definition “Probability”
Measurement tool that calculates the chance or likelihood of occurrence of an event
Definition “Genotypes”
The genes that are present in a person. The alleles which make up the genes of a person are referred to as the genotype of a person
Definition “Phenotypes”
Refers to an observable trait or physical trait
Definition “Heterozygous, Homozygous”
Heterozygous - Having two different alleles of a particular gene or genes.
Homozygous - Having two of the same alleles of a particular gene or genes.
Definition “Dominant, Recessive”
Dominant - When one allele overrides the expression of another allele
Recessive - When one allele is hidden by the expression of another allele
Definition “Codominance, Incomplete dominance”
Codominance - Neither alleles completely dominate and the two alleles are expressed together at the same time
Incomplete Dominance - When neither allele completely masks the other, and the two alleles combine to create a new trait that is a blend of both alleles
Definition “Carrier”
A person who has one copy of a mutated (changed) disease-causing gene but has no symptoms or mild symptoms
Definition “Sex-linked inheritance”
When the genes (and their alleles) are found on the sex chromosomes, either X or Y in humans. The alleles are expressed differently in males (XY) and females (XX)
Definition “Monohybrid cross”
Crossing parents who differ in only one trait
Definition “Dihybrid cross”
Crossing parents who differ in two traits (FOIL)
