Chapter 5 Genetics – Vocabulary

Term Definition
Dominant trait Genetic factor that blocks another genetic factor
Genetics Study of how traits are passed from parents to offspring
Heredity Passing of traits from parents to offspring
Hybrid when the two alleles are different – another name for heterozygous
Recessive trait Genetic factor that is blocked by the presence of a dominant factor
Allele Different form of a gene
Codominance Occurs when both alleles can be observed in the offspring's phenotype
Gene Section on a chromosome that has genetic information for one trait
Genotype Two alleles that control the phenotype of a trait (letters)
Heterozygous If the two alleles of a gene are different
Homozygous When the two alleles of a gene are the same
Incomplete dominance Occurs when the offspring's phenotype is a combination of the parent's phenotypes
Phenotype How a trait appears or is expressed (physically look like)
Polygenic inheritance Occurs when the multiple genes determine the phenotype of a trait
Punnett Square Model used to predict possible genotypes and phenotypes of offspring
DNA Organism's genetic material
Mutation Change in the nucleotide sequence of a gene
Nucleotide Molecule made of a nitrogen base, sugar, and a phosphate group that forms the basic structural unit of DNA
Replication Process of copying a DNA molecule to make another DNA molecule
RNA a type of nucleic acid that carries the code for making proteins from the nucleus to the cytoplasm
Transcription Process of making mRNA from DNA
Translation Process of making a protein from RNA
purebred when alleles are the same – another term for homozygous