genetics 3 Flashcards
a change in environment can affect the…
phenotype of an individual
phenotypic plasticity
the degree to which your phenotype is determined by your genotype
If environmental factors have a strong influence the phenotypic plasticity is…
high
If genotype can be used to reliably predict phenotype, phenotypic plasticity is
Low
examples of non-mendelian inheritance
- co-dominance
- Incomplete dominance
- Pleiotropy
- Polygenic inheritance
Co-Dominance
In this inheritance pattern the characters have more than the 2 typical alleles.
-2 alleles are inherited still tho
3 alleles for human blood types
A,B,O
how blood typing (co-dominance) differs from mandelian
- more than one set of alleles
-In AB blood types neither one is dominant (produces new genotypes)
Incomplete dominance
Heterozygous genotypes produce a phenotype which is a blended combination of the dominant and recessive phenotype
Hypercholesterolemia
cholesterol higher than normal
unaffected: HH
Heterozygous: Hh (high risk)
Homozygous recessive: hh (normal)
Incomplete dominance differs from mandelian pattern because…
this is a mixture of both/ not just one or another
Pleiotropy
one gene gives multiple different traits
-very rare
-ex: sickle cell anemia
how pleiotropy differs from mandelian pattern
in mandelian pattern
one gene= one trait
pleiotropy
one gene= multiple traits
polygenic inheritance
many genes make one phenotype
-the more dominant alleles an individual inherits, the more it adds to the phenotype
aneuploidy
human born with dif amount of chromosomes
non disjuction
homologous chromosomes dont split equally between cells due to extra spindle fibers forming and pulling on chromosomes
down syndrome
2n=47
Turner syndrome
2n=45 (always a female)
Kleinfelder sydrome
2n=47+ (always male)
karyotype
display of chromosomes in metaphase, used as a test
pedigree
chart showing gens
