MENDELIAN VS
NON-MENDELIAN
GENETICS
REVIEW MENDELIAN GENETICS
ATTACHED
FF or Ff
FREE
ff
F
F
f
Ff
Ff
f
Ff
Ff
Key Words: Dominant/Recessive, Homozygous/Heterozygous &
Genotype/Phenotype
MENDELIAN GENETICS = PATTERNS
FF
X ff
Ff
Ff
= 100% Ff
X Ff
X ff
= 1:2:1/FF:Ff:ff/
= 75% Ff
FF
X Ff
:
25% ff
= 75% FF 25% ff
BUT...
There are exceptions to these rules
ENTER NON-MENDELIAN GENETICS
Codominance -
Both traits are expressed equally in heterozygotes
+
=
WW
RR
Incomplete Dominance -
WR
Heterozygotes express a blend
=
+
RR
Multiple Alleles A
B
Polygenic Traits -
rr
Rr
More than two options/alleles
Blood types works in a
Codominance Pattern A
and B are Dominant and O
is recessive
O
controlled by more than one gene
Cannot be modeled
with punnett squares
Eye Color
Environmental Influence The dark color of the
Siamese cat is
determined by the
body temperature.
Colder = more
pigment
Hair Texture
Epigenetics and nature vs nurture
&
Learn More
Twins raised
separately could look
and act very different
because of different
foods/lifestyles