Biology Unit 3: Genetics

1. Complete the following chart comparing meiosis and mitosis.

Mitosis Meiosis

Produces sex cells (gametes) or body

cells (somatic)?

Cell division happens once or

twice?

Process results in two or four

daughter cells?

Daughter cells have 23 or 46

chromosomes each?

Cells produced are diploid (2n) or

haploid (n)?

2. After observing the karyotype below, identify the genetic disorder. (Ex: 47, XY + 13 would mean that this male has an extra chromosome #13, or Trisomy 13).

3. Which of the following could NOT be determined by a karyotype?

a. A patient has a cytosine where a guanine should be in one segment of DNA on chromosome 12.

b. The patient has an extra X chromosome and has been diagnosed with Klinefelter’s Syndrome.

c. A fetus will be a boy.

d. A person had chicken pox when they were 6 years old.

4. For each phenotype, give the genotypes that are possible.

Green peas (G) is dominant to yellow peas (g)

a. Green _________________b. Yellow _________________

Purple flower color (P) is dominant to orange (p)

c. Purple _________________d. Orange ________________

5. For each genotype, give the phenotypes that are possible.

Blond hair (B) is dominant to red hair (b)a. BB or Bb _________________b. bb ___________________

Dimples (D) is dominant to no dimples (d)c. DD or Dd ___________________d. dd ________________

6. What are the genotypes of all the individuals mentioned?

The presence of a space between your upper teeth is called diastema. This is a dominant trait. Not

having the space is a recessive trait. Mr. and Mrs. Patch had diastema corrected with braces. Briar, their son, does not have this trait. Mr. Stone does not have diastema, but Mrs. Stone does show the trait. Their daughter, Millie, does not show the

trait. Briar and Millie marry and have Daisy, who does not have the trait.

Mr. Patch ________ Mrs. Patch __________

Briar _____________ Mr. Stone ___________

Mrs. Stone _______ Millie _______________

Daisy ____________

7. In petunia flowers, red flowers (R) and orange flowers (O) are codominant. A cross between a red and an orange flower produces purple flowers (RO).

What would be the F1 genotypes and phenotypes of a cross between a red flower and a purple flower?

8. Complete the following pedigree if XH = Normal and Xh = hemophiliac. You only have to do the numbered individuals!

1 2

3 4 5

67

8

1. What are the chances of a color blind woman and man with normal vision having daughters that are color blind? Being carriers?

2. Hitchhiker’s thumb is recessive to normal, straight thumbs. Write the F1 phenotypes for a cross between a heterozygous, straight thumbed father and a homozygous mother with hitchhiker’s thumb.

3. A pink flower is crossed with a pink flower. The resulting F1 offspring are 1 red, 2 pink, and 1 white. What are the genotypes of parents?

9. Label each problem as monohybrid, codominance, or X-linked.

10. Using blood types, which children belong to which parents?

Parents Children

Parents 1 A- x B- Child A A+Parents 2 AB+ x AB+ Child B O –Parents 3 A- x O+ Child C B –Parents 4 O+ x O+ Child D AB+

For blood type and Rh, assume heterozygous!

11. Complete the following dihybrid cross.

In pigs short snout is dominant over long snout and curly tails are dominant over straight tails. If two heterozygous short-snouted, heterozygous curly-tailed pigs are crossed, what are the probabilities of…

a. Short-snouted, curly-tailed pigs?b. Short-snouted, straight-tailed pigs?c. Long-snouted, straight-tailed pigs?