Printed from Biology101.org

alleles ---- variant versions of a gene (each human has only two copies but more versions can exist within a population)
Gregor Mendel ---- an austrian monk who experimented with pea plants in the 19th century and provided the first detailed experiments of how traits are passed down from an individual to their offspring
unit factors ---- Mendels original term for genes
Independent Assortment ---- genes (unit factors) for different traits are randomly sorted into gametes
dominant ---- a trait or gene which is expressed even if only one copy is present
recessive ---- a trait or gene which is expressed only if two copies (both alleles) are present
Mendels Postulates ---- 1) Unit factors Exist in Pairs 2) Dominant / Recessive 3) Segregation 4) Independent Assortment
wild type ---- the normal or most commonly occuring version of a gene
chromosome ---- a relativley large segment of DNA containing many genes
phenotype ---- the characteristic that can be seen (caused by an underlying genotype)
genotype ---- the underlying genes that an organism has that causes the phenotype being observed
locus ---- the location of a gene on a chromosome
codominance ---- when two alleles can both be expressed, neither is dominant to the other (like A and B in human blood types)
homozygous ---- when an individual has two copies of the same allele
heterozygous ---- when an individual has two different alleles at a gene locus