Chapter 14 Mendelian Inheritance

Mendelian Genetics

• alt version of genes (alleles) account for variation in inherited characters

• each gene - inherits two alleles from each parents

• dominant vs recessive

The law of Segregation

during the formation of gamete, each gene separates from each other so that each gamete carries only one allele for each genes

• separate during meiosis and end up in different gametes

The Law of Dominance

in a heterozygote, one trait will conceal the presence of another trait for the same characteristic

The Law of Independent Assortment

one set of alleles of a gene pair segregates independently of another set of alleles for a different gene pair

monohybrid & monohybrid cross

a genetic cross involving organisms that differ in only one trait

dihybrids & dihybrid cross

a genetic cross involving organisms that differ in two traits

product rule

the probability that two or more independent events will occur together is the product of their individual probabilities

pedigree

a family tree that describes the interrelationships of parents and children across generations

Incomplete Dominance

when alleles are not completely dominant or recessive

Codominance

when a gene has more than two alleles

• two or more dominant alleles affect the phenotype in separate, distinguishable ways

Epistasis

when one gene can mask the effect of another

• expression of a gee at one locus alters the phenotypic expression of a gene at a second locus

complete dominance

occurs when phenotypes of the heterozygote and dominant homozygote are identical

incomplete dominance

two or more dominant alleles affect the phenotype in separate, distinguishable ways

• the intermediate trait is the heterozygous genotype