Heredity (p 115): The passing of genetic traits from parents to offspring
Gene: A set of instructions that control inherited traits
Alleles (p 120): An allele is one member of a pair of genes that is located at a specific position on a specific chromosome. Organisms have two alleles for each trait. Individual alleles control inheritance of traits. Some alleles are DOMINANT and some alleles are RECESSIVE
Genetics: The study of how traits are inherited through the actions of alleles.
Dominant Trait (p 117): The trait observed in the 1st generation when parents that have different traits are bred.
Recessive Trait (p 117): A trait that reappears in the 2nd generation after disappearing in the 1st generation when parents with different traits are bred.
Homozygous: Having identical alleles for a single trait.Heterozygous: Having two different alleles for a single trait.
Purebred: producing the same offspring with the same form of the trait as the parent
Example: Purebred short pea plants produce short offspring. Purebred offspring are IDENTICAL to parents. To produce purebred plants, Mendel allowed peas with one particular trait to self-pollinate.
Hybrid: Having 2 different alleles for each trait. In a hybrid, the recessive allele is “hidden” and the dominant allele is what we see.
Example: Mendel crossed two purebred pea plants, one purebred tall and one purebred short. The result was a hybrid TALL.
Phenotype: An organism's appearance or other detectable characteristics (PHYsical Feature=PHEnotype)
Genotype: The entire genetic makeup of an organism; also the combination of genes for one or more specific traits (Example: the genotype of a tall plant might be Tt or TT)
Probability: The likelihood that a possible future event will occur in any given instance of the event.
Punnett Square: A tool to predict the probability of certain traits in offspring that shows the different ways alleles can combine.
Incomplete Dominance: Production of a phenotype that is intermediate between the two homozygous parents.