Download Genetics Test Review

Name: ___________________________
Due: ______
Genetics Test Review
1. ______________ is the study of heredity.
2. Who is considered to be the Father of Genetics?
3. What is the difference between a gene and an allele?
4. Use the alleles T and t for height to fill out the table
Homozygous Dominant
Homozygous Recessive
Heterozygous
Genotype
Phenotype
5. What is the difference between homozygous and heterozygous? Give an example
6. What is the difference between genotype and phenotype? Give an example.
7. What is the difference between a dominant versus a recessive trait? Give an example
8. __________________ - This type of inheritance shows a blending effect. In other words, the dominant allele does
not completely cover the recessive allele. Give an example.
9. Co-Dominance – _______________________________________________________________________.
Give an example.
10. ___________________________ - type of inheritance where the allele is found on the sex chromosomes; usually the
X chromosome. Give an example.
11. What are the genotypic and phenotypic ratios and percentages for the following genetic combinations?
SHOW ALL WORK USING alleles R and r for monohybrid crosses and R, r, S, s for dihybrid crosses.
a. Heterozygous x heterozygous – Genotypic: __________ Phenotypic: ____________
What percentage of their children will be homozygous dominant?
b. Heterozygous x homozygous dominant – Genotypic: __________
What percentage of their children will be heterozygous?
Phenotypic: _________
c. Dihybrid heterozygous for both traits x heterozygous for both traits – Phenotypic: ____________
12. If a genetic trait displays epistasis, what does that mean?
13. Example of epistasis.
If P = purple flower petals and p = white flower petals and for a second trait C = color on and c = color off, then what
would be the phenotypes for the following possible genotypes?
CCPP = ________ CCPp = ________
CcPP = ________
CcPp = _________
CCpp = _______
Ccpp = ________
ccPP = ________
ccPp = _________
ccpp = ________
14. XX = ____________; XY =________________; who determines the sex of a child? _______________
15. Hemophilia is a sex-linked recessive trait. What is the genotype for:
a. A female with normal blood clotting factor - ________________
b. A female whose blood clots normally, but who is a carrier for the trait - _____________
c. A female hemophiliac - ______________
d. A male with normal blood clotting factor - _____________
e. A male hemophiliac - ______________
16. What are the genotypes and phenotypes for blood typing? What kind of trait is blood typing? _____________
Phenotype
Genotype
Another way to write genotype
Type A
AA, AO
IAIA or IAi
17. How can a parent, with A blood and a parent with B blood have children with O type blood? Support algebraically or
with a Punnett Square.
18. Which blood type is the universal recipient? _____________Donor? ____________Why?
19. What type of trait does this pedigree show, dominant or recessive?
How do you know?
Who shows the trait?
Are any of the members of the family carriers?
20. Total Ridge Count is a polygenic trait. (on fingerprints)
AABBCCDD represents a maximum ridge count and aabbccdd represents a minimum ridge count with a baseline of
60 for males and 30 for females. Each additional dominant allele adds 10 ridges to the TRC.
Genotype
Phenotype Male
Phenotype Female
aabbccdd
aaBBccDd
AabbCCDd
AAbbCCdd
AABBCCDD
Genetic Crosses
Solve the following monohybrid crosses. MUST SHOW YOUR WORK!
21. If out of 100 offspring of corn, 74 have round kernels and 26 have wrinkled, what are the probably genotypes and
phenotypes of the parents? Assume that round kernels are dominant.
22. Mating two pink flowers results in the following ratios: 25% white, 25% red and 50% pink. What were the parental
genotypes and what pattern of inheritance is this?
23. Mating a roan (red +white haired) bull with a white cow produces 50% white and 50% roan calves. Explain what
patterns of inheritance this is and how you know.
24. If Cindy and Bobby both have type A blood, can they have kids that have type O blood? Explain.
25. In fruit flies, the gene for white eyes is sex-linked recessive. (R) is red and (r) is white. Cross a white-eyed female with
a normal red-eyed male.
a. What percent of the males will have red eyes? White eyes?
b. What percent of the females will have red eyes? White eyes?
c. What total percent of the offspring will be white-eyed?
d. What percent of the offspring will be carriers of the white eye trait?
Solve the following dihybrid cross. MUST SHOW YOUR WORK!
26. In summer squash, white fruit color (W) is dominant over yellow fruit color (w) and disk-shaped fruit (D) is dominant
over sphere-shaped fruit (d). If a squash plant homozygous for white, disk-shaped fruit is crossed with a homozygous
for yellow, sphere-shaped fruit, what is the chance of producing a yellow disked fruited plant?