Mendelian Inheritance

• Crossed two variants differing in only one trait
• Helps show law of segregation

the trait that appears in the F1 generation

• alleles of a locus are placed into separate gametes during meiosis
• Each gamete receives only one or the other allele of a locus
• Each gamete has one allele of every locus

• - cross to test whether phenotype corresponds to homozygous dominant genotype or heterozygous genotype
• Always will cross of dominant(homo- or hetero-) vs recessive
• TTxtt
• Ttxtt

Either allele of one locus can go together in a gamete with either allele of a 2nd unlinked locus

dihybrid cross

• no functional protein is producedgenetic null
• – gene is lostfunctional null
• – no protein function

• a protein that doesn’t function as much as or in the same way as the wildtype protein
• Wildtype alleles are dominant to recessive alleles

• protein functions is a new way
• more protein is made than in wildtype
• protein can not be regulated as in wildtype

• a mutated protein disrupts the function of wildtype proteins
• dominant alleles are dominant to wildtype

Heterozygosity makes 3rd phenotype intermediate to the homozygous phenotypes

Blue, light blue, no color

heterozygosity produces a single unique phenotype different from either homozygous condition

heterozygosity creates a phenotype better or worse than homozygosity of either locus

homozygosity of an allele kills the cell or organism

• measures of variation in expression of a given allele occurs
• incomplete penetrance- lack of effect a deleterious allele has in an individual

• -mutation A and mutation B. B blocks A
• Enhancer-more robust expression

• prevalent alleles in a population
• encoded proteins are considered
• -normal function
• -normal expression level

• less common in natural pop, but >1%
• alters expression level or functionality of protein

inactive X chromosome

• If sons of affected mothers then sex llinked dom/rec
• If daughters of affected fathers then sex linked dom/rec