Answers
1.
Cross: TtCc x TtCc
Expected phenotypic ratio:
9 tall cut
= 9/16
= 450
3 tall entire
= 3/16
= 150
3 dwarf cut
= 3/16
= 150
1 dwarf entire
= 1/16
= 50
2.
Backcross TtCc to ttcc
Expected phenotypic ratio:
1 tall cut
= 145.25
1 tall entire
= 145.25
1 dwarf cut
= 145.25
1 dwarf entire
= 145.25
Parentals from q1 were TTCC and ttcc
50% should look like original parentals: tall cut or dwarf entire
50% should be different
3.
Cross TtCc x TTCC to get:
TTCC = Tall, cut
TTCc = Tall, cut
TtCC = Tall, cut
TtCC = Tall, cut
All phenotypes tall, cut. 4 different genotypes (above) in 1:1:1:1 ratio
4. Do a punnet square with X X and X Y.
Ratio of male to female offspring is 1:1
5.
Boy with hemophilia = X
h
Y
Boy’s mother = X
H
X
h
Boy’s father = X
H
Y
6.
X
H
X
H
x X
h
Y
Offspring genotypes:
1 X
H
X
h
= normal female (carrier)
1 X
H
Y
= normal male
7. Mother must be X
G
X
g
for the son to be colorblind
8. X
g
X
g
x X
G
Y
Offspring genotypes: 1 X
G
X
g
= normal female (carrier)
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '07
 DOUGLASGREEN
 Genetics, expected phenotypic ratio, wide bar females

Click to edit the document details