• Austrian monk
• 1856-1864 thousands of crosses
• Meticulously accurate records
• "Experiments on plant hybrids" 1866 (ignored for 33 years :( )
• 3 botanists: hugo de Vries, Carl Correns, Erich Von Tschermak (separate discoveries)

2 discrete hereditary factors for a characteristic 

when different inheritance from parents 1 is dominant 

segregation is randome in gamete formation 

Factors described by Mendel's particulate theory of inheritance

smallest heritable unit controlling a trait

Different versions of the same gene

homozygous TT or tt

heterozygous Tt

Differ in 2 characteristics

two possible patterns of inheritance linked or independent assortment 

heterozygote exhibits a phenotype that is intermediate between the corresponding homozygotes

two alleles

1:2:1

less common than recessive

Gain of function (protein gains a new or abnormal function)

Dominant-negative (Protein acts antaonistically to normal protein)

Haploinsufficiency (loss of function/ doesnt make enough poduct to give the wild type phenotype)

prevalent alleles in a population

Proteins made by them...

function normally

made in proper amounts

tend to be rare in natural populations

proteins made by them are...

reduced in amount or function

inherited in recessive fashion

in some instances a dominant allele doesnt influence the outcome of a trait in a heterozygote individual

may be influenced by environment or other genes

Polydactyly: autosomal dominant trait

affected individuals hae additional fingers/toes

a single copy of the polydactyly allele is usually sufficient to cause this condition

some times individuals my carry the dominant allele but wont exhibit the trait

the heterozygote advantage

heterozygote is more fit than the homozygotes

hemoglobin
SS-deform to cause sickle shape (sickle cell anemia)

AA - wont rupter when infected by malaria like SA will

SA heterozygote has the advantage

many genes have multiple alleles (3+)

genes that are present in a single copy/haploid genome, a maximum of two alleles are found in any particular diploid individual

(coat color/blood type ABO)

himalyayan is temp dependent, extremities dark because enzyme only works in cold temps

mostly males suffer from these diseases because they have no back up X to activate

dependent on if mother is effected or not (mother then 50/50 no mother no effected)

rare in humans

holandric

father to son

allele dominant in one sex but recessive in the other

mostly autosomal (not on X or Y)

baldness is related to testosterone so occures in males

occur in only one of the two sexes and is due to an anatomical limitation

breasts and beards

result of mutations in essential genes, usually inherited in a recessive manner, and prevent cell division

huntington disease

semi-lethals (kill only some dependent on environment)

manx cats (ratios shortened 2:1)

most genes have multiple effects

effect of a single gene on the phenotype is called pleiotropy

(one gene for eyesight, coat color and hearing)

reasons:

gene produced affect cell function in more than one way

gene expressed in different cell types

gene expressed at different stages of development

when alleles of one gene mask the phenotypic effects of the alleles of another

(cross involving two-gene interaction produce two phenotypes)