chapter 11- Medelian Patterns of Inheritance

particulate theory of inheritance

based on inheriting particles of inheritance (genes) from two parents. The combination of those particles determined physical traits.

gene

a unit of heredity that is transferred from a parent to offspring and determines a characteristic of the offspring

gene

a sequence of dna forming part of a chromosome, the order of which determines the sequence of amino acids in a protein (codes for protein)

allele

variant form of a given gene

law of independent assortment

the pair of genes for one trait segregate independently of the genes for other traits
all possible combinations of genes can occur in the gametes

genotype

refers to the two alleles an individual has for a specific trait
YY, Yy, or yy
if identical it is Homozygous
If different it is heterozygous

phenotype

it refers to the physical appearance of the individual

Dominant allele

always expressed, masks the expression of the recessive allele

Genetic disorders

medical conditions caused by alleles inherited from parents

autosome

any chromosome other than a sex chromosome (X or Y)

autosomal disorders

disorders caused by genes on autosomes

pleiotropy

an allele effects more than one phenotype

codominance

heterozygote shows some aspect of the phenotypes of both homozygotes