2. REEBOP LAB- day 2
H.W. Print 14.1 Notes and do these:
EVEN MORE
PATTERNS OF INHERITANCE PRACTICE PROBLEMS (Sex Linked Inheritance Practice
Problems)
Answer these
questions on a separate sheet of paper. Show your work!!!!!
1. Colorblindness is a
sex-linked, recessive disorder. What are the probable offspring outcomes
from a father who is colorblind and a mother who is homozygous normal vision?
Show your work!
2. Myopia (poor eyesight) is
a sex-linked, recessive disorder found in Reebops. What are the probably offspring outcomes from
a father reebop who has normal eyesight and a mother reebop who was myopia. Show your work with a punnett square!
3. Duchenne Muscular
Dystrophy is caused by a recessive allele located on the X chromosome.
a. Draw a Punnett square that
show how two unaffected people can have a child with muscular dystrophy.
Include the genotypic ratio and phenotypic ratio for the offspring.
b. Is the child with muscular
dystrophy male or female?
c. What is the probability
that the couple's next child will have muscular dystrophy?
d. What percentage of the
couple's male children will probably have muscular dystrophy?
e. What percentage of the
couple's female children will probably have muscular dystrophy?
4. Hypophosphatemia, a disorder that causes low
phosphate levels in the body and can cause bowed legs, is caused by a dominant
allele on the X chromosome.
a. Using A to represent the
allele for hypophosphatemia, draw a punnett square that shows the possible
offspring from a woman with genotype XAXa and a man with
genotype XAY.
b. What percentages of the
children have hypophosphatemia?
c. Are males more likely to
have the disorder than females? Explain.
d. Draw a Punnett square that
show the possible offspring of a woman with a normal phenotype and a man with
hypophosphatemia. Include the genotypic and phenotypic ratios for the
offspring.
e. What percentages of the
children have the disorder for this cross?
f. What percentages of the
male offspring have the disorder for this cross? Explain this result.
5. Color-blindness is a
sex-linked trait in humans. Normal vision (XB) is dominant
over colorblindness. Achondroplasia (a type of dwarfism) is an autosomal
disorder. Achondroplasia is dominant (A) to average height (a), though if
a zygote inherits two dominant alleles (AA) it dies at birth.
a. Complete a two-factor
Punnett square to predict the offspring for a colorblind, male with
achondroplasia (XbYAa) and a heterozygous normal vision female with
achondroplasia (XBXbAa).
b. What is the probability
that they will have a child that is colorblind and Achondroplasiac? Don't
forget to exclude offspring with AA genotypes
6. What is the pattern of
inheritance that is illustrated for questions #1-5?
