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BI-125 Botany
Mendelian Genetics

Vocabulary of Genetics


Mendel

Mendel's Principles

Apply only to diploid species.
Mendel worked with garden peas.

the Monohybrid Cross

no dominance
trait: flower color
orange coneflower, Rudbeckia fulgida
F-1
yellow-orange
male
X yellow-orange
female
Rr X Rr F-2
female RR 1 25% orange
R r Rr 2 50% yellow-orange
male R RR Rr rr 1 25% yellow
r Rr rr Σ 4 100%

with dominance
trait: flower color
wallflower, Erysimum capitatum
F-1
hybrid
Yellow
male
X hybrid
Yellow
female
Yy X Yy F-2
female YY 3 75% yellow
Y y Yy
male Y YY Yy yy 1 25% white
y Yy yy Σ 4 100%

Dihybrid

dihybrid, no dominance

purple stem, hairiness
Brassica rapa, turnip (Wisconsin Fast Plants®)
F-1
hybrid
purplish, hairy
male
X hybrid
purplish, hairy
female
ANL/anl, H/h X ANL/anl, H/h F-2
female ANL/ANL, H/H 1 6.25% tall,
v. hairy
ANL, H ANL, h anl, H anl, h ANL/ANL,
H/h
2 12.5% tall,
hairy
m
a
l
e
ANL, H ANL/ANL,
H/H
ANL/ANL,
H/h
ANL/anl,
H/H
ANL/anl,
H/h
ANL/ANL,
h/h
1 6.25% tall,
hairless
ANL, h ANL/ANL,
H/h
ANL/ANL,
h/h
ANL/anl,
H/h
ANL/anl,
h/h
ANL/anl,
H/H
2 12.5% purplish
v. hairy
anl, H ANL/anl,
H/H
ANL/anl,
H/h
anl/anl,
H/H
anl/anl,
H/h
ANL/anl,
H/h
4 25% purplish,
hairy
anl, h ANL/anl,
H/h
ANL/anl,
h/h
anl/anl,
H/h
anl/anl,
h/h
ANL/anl
h/h
2 12.5% purplish
hairless
anl/anl,
H/H
1 6.25% green
v. hairy
anl/anl,
H/h
2 12.5% green
hairy
anl/anl,
h/h
1 6.25% green
hairless
Σ 16 100.00%
note: hairiness is actually a multigene trait;
H, h are not the 'correct' symbols for the alleles

dihybrid, with dominance

tall, yellow-green leaf (y-green); [both recessive]
Brassica rapa, turnip (Wisconsin Fast Plants®)
F-1
hybrid
normal, green
male
X hybrid
normal, green
female
EIN/ein, YGR/ygr X EIN/ein, YGR/ygr F-2
female 1-EIN/EIN,
YGR/YGR
9 56.25% normal,
green
EIN,
YGR
EIN,
ygr
ein,
YGR
ein,
ygr
2-EIN/EIN,
YGR/ygr
m
a
l
e
EIN,
YGR
EIN/EIN,
YGR/YGR
EIN/EIN,
YGR/ygr
EIN/EIN,
YGR/YGR
EIN/EIN,
YGR/ygr
2-EIN/ein,
YGR/YGR
EIN,
ygr
EIN/EIN,
YGR/ygr
EIN/EIN,
ygr/ygr
EIN/ein,
YGR/ygr
EIN/ein,
ygr/ygr
4-EIN/ein,
YGR/ygr
ein,
YGR
EIN/ein,
YGR/YGR
EIN/ein,
YGR/ygr
ein/ein,
YGR/YGR
ein/ein,
YGR/ygr
1-EIN/EIN,
ygr/ygr
3 18.75% normal,
y-green
ein,
ygr
EIN/ein,
YGR/ygr
EIN/einl,
ygr/ygr
ein/ein,
YGR/ygr
ein/ein,
ygr/ygr
2-EIN/ein
ygr/ygr
1-ein/ein,
YGR/YGR
3 18.75% tall
green
2-ein/ein,
YGR/ygr
1-ein/ein,
ygr/ygr
1 6.25% tall
y-green
Σ 16 100.00%


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