Genetic Inheritance Flashcards
What component of the genome contributes the most - autosomal or sex-linked
Autosomal
Simple vs complex inheritance
Simple - 2 factors control inheritance pattern (chromosomal location - X or Y, phenotype expression pattern - dominant or recessive)
Complex - multiple genes and environmental factors contribute to trait aka polygenic
What are the main modes of simple inheritance
Autosomal dominant
Autosomal recessive
X-linked dominant
X-linked recessive
Are autosomal dominant disorders more severe in heterozygotes or homozygotes (usually)
Homozygotes
Divide blood types into dominant or recessive
O: recessive
A&B: co-dominant
In pedigrees males are…
Square
In pedigrees females are…
Round
What can dominant disorders result from
Haploinsufficiency - single normal allele is not sufficient to produce normal
Dominant negative effect - altered gene product antagonizes normal product
Gain of function - changes gene product specificity or expression
Autosomal recessive inheritance pedigree generalizations
Diseases obscured in pedigree
Parents of affected offspring are not affected
Not usually all offspring affected
Autosomal dominant inheritance pedigree generalizations
Every affected animal has an affected parent
Male-male transmission possible
Heterozygotes affected
General P(A) OR P(B) rule
p(A) + p(B)
General P(A) AND P(B) rule
p(A) x p(B)
X-linked dominant inheritance pedigree generalizations
Affected individuals have at least one affected parent
Heterozygotes affected
Male-female transmission
No male-male transmission
Female transmission resembles autosomal dominant
X-linked recessive inheritance pedigree generalizations
Disease more frequent in males
No male-male transmission
All daughters of affected males are carriers
