Advanced Biology
Chapter 11 Vocabulary
genetics: scientific study of heredity
fertilization: process in sexual reproduction in which male and female reproductive cells join to form a new cell
true-breeding: term used to describe organisms that produce offspring identical to themselves if allowed to selfpollinate
trait: a specific characteristic that varies from one individual to another
hybrids: the offspring of crosses between parents with different traits
gene: sequence of DNA that codes for a protein and thus determines a trait
alleles: one of a number of different forms of a gene
segregation: separation of alleles during gamete formation
gametes: specialized cell involved in sexual reproduction
probability: likelihood that a particular event will occur
Punnett square: a diagram showing the gene combinations that might result from a genetic cross
homozygous: term used to refer to an organism that have two identical alleles for a particular trait
heterozygous: term used to refer to an organism that has two different alleles for the same trait
phenotype: physical characteristics of an organism
genotypes: genetic make up of an organism
independent assortment: independent segregation of genes during the formation of gametes
incomplete dominance: situation in which one allele is not completely dominant over another
codominance: a situation in which both alleles contribute to the phenotype of the organism
multiple alleles: three or more alleles of the same gene
polygenic traits: trait controlled by two or more genes
homologous: term used to refer to chromosomes that each have a corresponding chromosome from the opposite sexparent
diploid: term used to refer to a cell that contains both sets of homologous chromosomes
haploid: term used to refer to a cell that contains only a single set of chromosomes and therefore only a single set of
genes
meiosis: process by which the number of chromosomes per cell is cut in half through the separation of homologous
chromosomes in a diploid cell
tetrad: structure containing 4 chromatids that forms during meiosis
crossing-over: process in which homologous chromosomes exchange portions of their chromatids during meiosis
gene map: diagram showing the relative locations of each known gene on a particular chromosome