NAME:DATE:BLOCK:

1. For each genotype, indicate whether it is heterozygous (HE) or homozygous (HO)

AA ____
Bb ____
Cc ____
Dd ____ / Ee ____
ff ____
GG ____
HH ____ / Ii ____
Jj ____
kk ____
Ll ____ / Mm ____
nn ____
OO ____
Pp ____

2. For each of the genotypes below, determine the phenotype.

Purple flowers are dominant to white flowers
PP ______
Pp ______
pp ______/ Brown eyes are dominant to blue eyes
BB ______
Bb ______
bb ______
Round seeds are dominant to wrinkled
RR ______
Rr ______
rr ______/ Bobtails are recessive (long tails dominant)
TT ______
Tt ______
tt ______

3. For each phenotype, list the genotypes. (Remember to use the letter of the dominant trait)

Straight hair is dominant to curly.
______straight
______straight
______curly / Pointed heads are dominant to round heads.
______pointed
______pointed
______round

4. Set up the square for each of the crosses listed below. The trait being studied is round seeds (dominant) and wrinkled seeds (recessive)

Rr x rr

What percentage of the offspring will be round? ______

Rr x R r

What percentage of the offspring will be round? ______

RR x Rr

What percentage of the offspring will be round? ______

In rabbits, grey hair is dominant to white hair. Also in rabbits, black eyes are dominant to red eyes.

GG = gray hair
Gg = gray hair
gg = white hair / BB = black eyes
Bb = black eyes
bb = red eyes

5. What are the phenotypes (descriptions) of rabbits that have the following genotypes:

Ggbb ______ggBB ______
ggbb ______GgBb ______

6. A male rabbit with the genotype GGbb is crossed with a female rabbit with the genotype ggBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring.

How many out of 16 have grey fur and black eyes? ____

How many out of 16 have grey fur and red eyes? _____

How many out of 16 have white fur and black eyes? ____

How many out of 16 have white fur and red eyes? _____

7. A male rabbit with the genotype GgBb is crossed with a female rabbit with the genotype GgBb The square is set up below. Fill it out and determine the phenotypes and proportions in the offspring. Draw the Punnet Square.

How many out of 16 have grey fur and black eyes? ____

How many out of 16 have grey fur and red eyes? _____

How many out of 16 have white fur and black eyes? ____

How many out of 16 have white fur and red eyes? _____

Practice with Crosses. Show all work!

8. A TT (tall) plant is crossed with a tt (short plant).
What percentage of the offspring will be tall? ______

9. A Tt plant is crossed with a Tt plant.
What percentage of the offspring will be short? ______

10. A heterozygous round seeded plant (Rr) is crossed with a
homozygous round seeded plant (RR).
What percentage of the offspring will be homozygous (RR)? ______

11. A homozygous round seeded plant is crossed with a homozygous
wrinkled seeded plant. What are the genotypes of the parents? ______x ______

What percentage of the offspring will also be homozygous? ______

12. In pea plants purple flowers are dominant to white flowers.
If two white flowered plants are cross, what percentage of their
offspring will be white flowered? ______

13. A white flowered plant is crossed with a plant that is
heterozygous for the trait. What percentage of the
offspring will have purple flowers? ______

14. Two plants, both heterozygous for the gene that controls
flower color are crossed. What percentage of their offspring
will have purple flowers? ______
What percentage will have white flowers? ______

15. In guinea pigs, the allele for short hair is dominant. (S)
What genotype would a heterozygous short haired guinea pig have? ______
What genotype would a purebreeding short haired guinea pig have? ______
What genotype would a long haired guinea pig have? ______

16. Show the cross for a pure breeding short haired guinea pig
and a long haired guinea pig.
What percentage of the offspring will have short hair? ______

17. Show the cross for two heterozygous guinea pigs.
What percentage of the offspring will have short hair? ______
What percentage of the offspring will have long hair? ______

18. Two short haired guinea pigs are mated several times. Out of 100
offspring, 25 of them have long hair. What are the probable
genotypes of the parents? ______x ______Show the cross to prove it!

Cattle Genetics

Using the information provided, show the punnett square for each of the crosses and answer the questions. SHOW ALL WORK! YOU MAY USE A SEPARATE SHEET OF PAPER.

Female= XXMale= XYPolled = PHorned = p

Black coat = BRed coat = bSolid = SSpotted = s

Face color white = FFace color black = fSolid tail = TStriped tail = t

Solid legs = Lstocking legs = l

  1. A black coated cow is crossed with a red coated bull (Bb X bb). What is the percentage of black calves? What is the percentage of red calves?
  2. A horned cow is crossed with a polled bull (pp X Pp). What is the percentage of horned calves? What is the percentage of polled calves? Which is more advantageous and why?
  3. A solid tailed cow is cross with a solid tailed bull (Tt X Tt). What is the percentage of solid tailed calves? What is the percentage of striped tailed calves?
  4. A cow is crossed with a bull (XX x XY). What is the percentage the calves will be female? What is the percentage the calves will be male?
  5. A solid legged cow is crossed with a solid legged bull (Ll X Ll). What is the percentage the calves will solid legged? What is the percentage the calves will be stripped legged?
  6. A black coated cow is crossed with a black coated bull. (Bb X Bb). What is the percentage of black calves? What is the percentage of red calves?
  7. A solid legged cow is crossed with a stocking legged bull (LL X ll). What is the percentage of stocking legged calves? What is the percentage of solid legged calves?