Honors Biology: Mod 8 Introduction to Genetics Vocabulary

genetics

scientific study of heredity

hybrid

offspring of crosses between parents with different traits (ex. Ff or heterozygous)

gene

sequence of DNA that codes for a protein and thus determines a trait; factor that is passed from parent to offspring

allele

one of a number of different forms or variations of a gene (ex. dominant = F, recessive = f)

segregation

separation of alleles during gamete formation

gamete

sex cell (ie. sperm or egg cell)

phenotype

physical characteristic of an organism (ex. freckles vs. no freckles)

genotype

genetic makeup of an organism (ie. homozygous vs. heterozygous)

independent assortment

principle stating that genes for different traits can separate independently during the formation of gametes

polygenic traits

trait controlled by two or more genes (ex. skin or eye color)

homologous

refers to chromosomes in which one set comes from the male parent and one set comes from the female parent

diploid

refers to a cell that contains two sets of homologous chromosomes or two sets of genes

haploid

refers to a cell that contains only one set of chromosomes or 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

crossing over

process in which homologous chromosomes exchange portions of their chromatids during meiosis