The document describes genetic crosses between organisms with two alleles (A and a) at a particular locus. It shows the results of crosses in a Punnett square format and states the expected genotype and phenotype ratios of the offspring.

1. – -–
–
-
-
-
-
-
–-
---

2. P tt TT
G t T
Tt
F1
Tt Tt
G2 T t T t
F2 BB Bb Bb bb
b B

3. P bb BB
G B B
b b
F1 Bb Bb
G2
B b B b
F2 BB Bb Bb bb
––
––
–
w W
P ww WW
G w W
F1 Ww Ww
G2 W w W w
F2 WW Ww Ww ww

4. B B
a A
P1 aabb AABB
G1 ab AB
AaBb
AB Ab aB ab
AB AABB AABb AaBB AaBb
F2
Ab AABb AAbb AaBb Aabb
aB AaBB AaBb aaBB aaBb
Ab AaBb Aabb aaBb aabb
–

5. -
-
-
-
P rr Rr P rr RR
G r R r G r R
F Rr rr F Rr

6. –
R
w
P. RR WW
G. R R W W
F1. RW RW
G2. R W R W
F2. RR RW RW WW
B
W
P: WW BB
G: W W B B
F1 : BW BW
G: B W B W
F2 : BB BW BW WW

7. -
a A
b B
AAbb , aaBB
-
P AAbb aaBB
G Ab aB
F1 AaBb

8. AB Ab aB ab
AB AABB AABb AaBB AaBb
F2
Ab AABb AAbb AaBb Aabb
aB AaBB AaBb aaBB aaBb
Ab AaBb Aabb aaBb aabb
---------------------------------------------------------------------------------------------------
-
-
-
--
-
AABB AAbb , aaBB , aabb
-
AaBB , AABb aaBb , Aabb
-
AaBb

9. SS
Ss
ss
-
A,B,O
A, B O -
A,B -
-
AA AO A
BB BO B
AB AB
OO O

10. O AB , A
B 0 , B
P. BO OO P. AO AB
G. B O O G. A O A B
F. BO OO F. AA AO AB BO
B O
O,A AB , A B A AO , AA A
O, B AB , B A B BO , BB B
AB - B , A AB AB
O A,B - OO O

11. AB
O
B , A
-
B A -
-
A A -
B B -
AB B A -
O -
Rh+
Rh-
Rh+
Rh-
Rh+Rh- Rh+Rh+
Rh-Rh-

12. Rh- Rh+