A
Different versions of a gene found at the same location (locus) on homologous chromosomes.
ALLELES
The fundamental units of heredity.
GENES
Thread-like structure made of DNA.
CHROMOSOMES
Having two identical alleles for a particular gene.
HOMOZYGOUS
Having two different alleles for a particular gene.
HETEROZYGOUS
A genetic trait that is expressed when present, overriding the expression of its recessive allele.
DOMINANT
The likelihood or chance of a particular outcome occurring, often expressed as a fraction or percentage.
PROBABILITY
A diagram used to predict the possible genotype combinations of offspring from a genetic cross between two parents.
PUNNETT SQUARE
A genetic trait that is expressed nonly in the absence of the dominant trait.
RECESSIVE
The genetic makeup of an organism, consisting of alleles it inherits from its parents.
GENOTYPE
A diagrammatic representation of a family's genetic history, showing the transmission of traits across generations.
PEDIGREE
The observable traits or characteristics of an organism.
PHENOTYPE
The principles of inheritance discovered by Gregor Mendel, including the law of dominance, law of segregation and the law of independent assortment.
MENDELIAN INHERITANCE
A genetic cross involving two different traits.
DIHYBRID CROSS
The ratio of different genotypes produced by a genetic cross, representing the probability of each genotype occurring among the offspring.
GENOTYPIC RATIO
A genetic cross involving only one trait.
MONOHYBRID CROSS
The ratio of different phenotypes produced by a genetic cross, representing the probability of each phenotype occurring among the offspring.
PHENOTYPIC RATIO