TEST REVIEW: GENETICS I
ANSWER ON A SEPARATE SHEET OF PAPER FOR CREDIT
I. Vocabulary: Define the following words:
1. genetics
7. dominant
2. allele
8. recessive
3. heterozygous/hybrid
9. dihybrid cross
4. homozygous/pure
10. monohybrid cross
5. heredity
11. gamete
6. trait
12. P generation
13. F1 generation
14. F2 generation
15. genotype
16. phenotype
17. incomplete dominance
18. codominance
19. law of segregation
20. law of dominance
21. law of independent
assortment
22. pollination
23. Gregor Mendel
II. Gametes: Fill in the chart with the possible gametes for each individual.
Possible gametes
AaBB
AA
AAbbCcDd
aaBbCcDdEE
AaBb
III. Problems: Solve the following problems showing ALL work and answering ALL questions.
1. In humans, acondroplasia “dwarfism” (D) is dominant over normal (d). A homozygous dominant (DD) person dies
before the age of one. A heterozygous (Dd) person is dwarfed. A homozygous recessive individual is normal. A
heterozygous dwarf man marries a dwarf heterozygous woman……..
a. How many traits are being studied?
b. What type of genetics problem is this?
c. What is the probability of having a normal child?
d. What is the probability that the next child will also be normal?
e. What is the probability of having a child that is a dwarf?
f. What is the probability of having a child that dies at one from this disorder?
2.
In humans, free earlobes(F) is dominant over attached earlobes (f). If one parent is homozygous dominant for free
earlobes, while the other has attached earlobes…
a. Can they produce any children with attached earlobes?
b. How many traits are being studied?
c. What type of genetics problem is this?
3.
In brobees, the long hair allele is dominant over the short hair allele, and the green hair allele is dominant over the
orange hair allele. A brobee heterozygous for hair LENGTH and hair COLOR is crossed with a plant that is orange and
heterozygous for hair LENGTH.
a. How many traits are being studied in this problem?
b. What type of genetics problem is this?
c. What is the expected phenotypic ratio for the offspring?
d. What is the expected genotypic ratio for the offspring?
4.
In aliens, suppose a blue skinned alien is mated with a yellow skinned alien and all of their children are green.
a. How many traits are being studied in this problem?
b. What kind of genetics problem is this?
c. What are the genotypic percentages for the offspring?
d. What are the phenotypic percentages for the offspring?
e. Construct a Punnett square to show the F2 generation. Identify genotype and phenotype % for the offspring.
5.
In aliens, a blue skinned alien is mated with a yellow skinned alien and all their children are blue and yellow spotted.
a. How many traits are being studied in this problem?
b. What kind of genetics problem is this?
c. Now construct a Punnett square to show the results of a cross between a spotted alien and a yellow skinned
alien. Identify the genotype and phenotype percentages for the offspring.
BE SURE TO REVIEW ALL PROBLEMS WE HAVE WORKED ON. THIS REVIEW ONLY PROVIDES A FEW EXAMPLES. THE TEST WILL INCLUDE COMPLETE
DOMINANCE, INCOMPLETE DOMINANCE, CO DOMINANCE AND DIHYBRID CROSSES. YOU WILL ALSO BE REQUIRED TO ANALYZE THE RESULTS OF THESE
CROSSES BY ANSWERING QUESTIONS ABOUT THE OFFSPRING AND PARENTS.