Transcript Genetic Patterns in Tribbles

Genetic Patterns in Tribbles
#1 a) Red
b) black
c) pheno 3:1 red to black
geno 1:2:1 RR Rr rr
P1 RR x rr
F1 Rr
Rr x Rr
F2 RR Rr
Rr
rr
Tribbles #2
A. Codominance
both blue & yellow hairs
B. HB and HY
C. HB HY x HB HB
green blue
HB HY
HB HB HB HB HY
HB HB HB HB HY
D. ratios
Pheno: 50% blue hair
50% green (both)
1:1
Geno: 50% HB HB
50% HB HY
1:1
#3
• a) Red, Blue and Yellow
H R HB HY
• b) black and white
hb
hw
• c) black is recessive to red, blue, & yellow,
but black is dominant to white
#4
• A) spotted and blue hair • D) To get a 9:3:3:1 ratio
that is a normal dihybrid
heterozygous cross:
• B) solid and black hair
• TtHBhb x TtHBhb
B Thb tHB thb
•
TH
• C) T (spots) t (solid)
B
•
TH
B
b
H
h
• Thb
• tHB
• thb
#5
• A) spotted and red hair
• B) solid and white hair
• C) white spots will not show on a white
background (they blend in, but the spotted
genes will still be there!)
#6
• A) gene D seems to control how much
pigment is made
• B) There is a blending of color amounts,
therefore this is incomplete dominance
• C) no pigment is made therefore they are
white
• D) hwhw
dd
hwhw TT or tt
• white hair no pigment
white hair & spots/solid
#7
• A) HB HR DD x HY HR dd
• B) HY HR Dd
• purple with incomplete pigment production
#8
• A) must be sex-linked if only males have
the trait (or a majority of males have trait)
• B) HB HB XnY x HB HB XNXn
#9 Genes in Tribbles chart
TRAIT
Dominant Allele Recessive Allele
Coat Color
Blue
HB
Black hb
Red
HR
HY
White hw
Yellow
Coat Pattern
Normal XN
Plaid Xn
Pigment
Production
Normal D
No pigment d
Spots
Spots T
Solid t
Additional Practice
• http://biology.clc.uc.edu/courses/bio105/gen
eprob.htm
• This is on my website under links also!!
– Go there for practice.