Genetics Practice Sheet

____points!!

Section A (__ Points)

Identify whether the allele is dominant (D) or recessive (R).

  1. B ______4. A ______
  2. b ______5. f ______
  3. W ______6. m ______

Section B (__ Points)

Identify whether the gene pair will display as dominant (D) or recessive (R).

  1. BB ______4. Gg ______7. Aa ______
  2. aa ______5. FF ______8. DD ______
  3. Ww ______6. pp ______

Section C (__ Points)

Identify whether the genotype is homozygous (Ho) or heterozygous (He).

  1. HH ______4. yy ______7. JJ ______
  2. GG ______5. Ff ______8. Pp ______
  3. Bb ______6. mm ______

Section D (__ Points)

Identify whether the genotype is homozygous dominant (HomD), heterozygous (He), or homozygous recessive (HomR).

  1. KK ______5. JJ ______9. DD ______
  2. ll ______6. Hh ______10. Ww ______
  3. dd ______7. cc ______
  4. Tt ______8. RR ______

Section E(__Points)

Identify the phenotype.

  1. Brown eyes are dominant to green eyes. Fill in the blanks with “brown” or “green” eyes.

BB ______Bb ______bb ______

  1. A full head of hair is dominant to baldness. Fill in the blanks with “hair” or “bald”.

Hh ______hh ______HH ______

  1. Curly hair is dominant to straight hair. Fill in the blanks with “curly” or “straight”.

cc ______CC ______Cc ______

  1. Tongue rolling is a dominant trait, so rollers are dominant and nonrollers are recessive

Fill in the blanks with “roller” or “nonroller”.

TT ______tt ______Tt ______

Section F (__ Points)

  1. This Punnett Square shows a father and mother that are both heterozygous for tongue rolling. Tongue rolling is a dominant trait. The possible genotypes for their children are shown.
  2. Color the heterozygous offspring yellow, homozygous recessive offspringred and the homozygous dominant offspringpurple.
  1. How many offspring have heterozygous genotypes?

____ out of ______OR ______%

  1. How many offspring have homozygous genotypes?

____ out of ______OR ______%

  1. How many offspring have homozygous recessive genotypes?

____ out of ______OR ______%

  1. What is the probability of a heterozygous child?

______%

  1. What’s the probability that their child will be able to roll his tongue?

______%

Section G (__ Points)

1. Felicia and Christian want to know if their child will have curly (H) or straight (h) hair. The mom has curly hair and the dad has straight hair. Fill in the Punnett square to see what type of hair their childmay have.

a. Is Felicia’s genotype on the left or top? ______

b. Is Felicia’s genotype homozygous or heterozygous?

______

c. Explain why Felicia’s hair is curly.______

______

______

d. Use a colored pencil to lightly shade in the boxes that are heterozygous.

e. What is the probability that Felicia and Christian’s child will have curly hair?______%

f. What is the probability that their child will have straight hair? ______%

BONUS

2. The same couple wants to know what color hair their child will have. Felicia has brown hair (B) but her father had red hair (b). Christian has red hair (b) and both his parents had red hair too. Fill in a Punnett square to see what color hair their childmay have.

a.What percentage of their children will have brown hair?

______%

b.What percentage of their children will have red hair?

______%

c.Explain how a child can have red hair when both parents have brown

hair.______

______