Review for Genetics - H (use problem sets too!)
Chapter 9. Fundamentals of Genetics
1. Be able to describe and use the following vocabulary easily:
a. Characteristic, trait, self-pollination, cross-pollination, true breeding, P F1 and F2
generations, dominant recessive, allele, gamete, offspring, progeny, heterozygous,
homozygous, test cross, dihybrid, monohybrid, genotype, phenotype. Be able to
identify bolded terms as they relate to Punnett squares. A good way to practice the
vocab is to create a story about your dragon.
2. Identify the purpose and “set up” of a test cross.
3. List and differentiate between the Laws of Dominance, Segregation and Independent
assortment. What type of inheritance pattern do these refer to? What does each law refer to
(in terms of chromosomes and genes).
4. How do current day molecular genetics support Mendel’s conclusions?
What types of inheritance patterns did he study?
Why are many genes (even sometimes those found on the same chromosome)
independently assorted?
5. What are three things we know now, that Mendel did not know?
What inheritance patterns do we now know?
What do we know about linkage?
6. Explain why the Punnett square is simply a visualization of the random assortment and
recombination of genes during meiosis and fertilization (write a paragraph that uses vocab
words to explain what a Punnett square means )
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Review for Genetics - H (use problem sets too!)
7. Be able to model (identify parents, and inheritance patterns and use a Punnett square) and
predict outcomes for monohybrid (single gene) word problems using Punnett squares and
“word explanations”. For dominant/recessive, codominant, or incompletely dominant patterns
(see your problem sets)
8. Incompletely dominant patterns and codominance patterns are sometimes shown using the
notations and problem setup provided in class Bb (incomplete); CwCB (codominant) and XAXA (sex
linked), multiple alleles (ABO blood group or any other problem that involves ONE gene but 3 or
more alleles). Choose a problem from your problem sets and for each scenario and recopy it
into your review sheet.
9. Be able to predict the phenotypic and genotypic outcomes of a dihybrid test cross (two nonlinked genes) using Punnett squares AND mathematical methods.
a. How many alleles does each gamete show in the Punnett square
b. How do you create “all possible combinations” for the gametes and the zygotes
(offspring).
c. Determining genotype vs. phenotype ratios for two traits.
10. Create a Punnett square that shows the cross between two Blue (B) and Horned (H) fish The
mother is heterozygous for both traits, while the father is homozygous recessive for both traits.
The recessive alleles are White (b) and No Horn (h).
11.
12. Parent genotype father____________
Mother _______________
13. Parent phenotypes: father___________ Mother_________________
14. Possible gametes for father:______________________ for mother
________________________
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Review for Genetics - H (use problem sets too!)
Chapter 12. You will be tested on the information found in the questions below:
1.
What is a sex-linked trait? On which sex chromosome are most traits found?
2. Many sex-linked genes exhibit a disease condition from a recessive allele much more frequently
in males (as compared to females). Why would X-linked diseases show up more in men?
3. What are linked genes? Who discovered these genes? Where would you find linked genes
(give me two descriptors). How can genes become unlinked?
4.
A pedigree is a diagram of family relationships that uses symbols to represent people and lines
to represent genetic relationships. These diagrams make it easier to visualize relationships
within families, particularly large extended families. Pedigrees are often used to determine the
mode of inheritance (dominant, recessive, etc.) of genetic diseases. A sample pedigree is below.
5. (5-8not in the book). How do you determine by looking at a pedigree, whether a disease due to
an autosomal recessive allele?
6. When a pedigree shows an autosomal dominant disease, what key inheritance patterns do you
see in the pedigree?
7. When a pedigree shows an X-linked disease, what key inheritance patterns do you see in the
pedigree?
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Review for Genetics - H (use problem sets too!)
8. What is a polygenic characteristic? What is an example of a polygenic characteristic? What
distribution does a polygenic characteristic typically show?
9. What is a multiple allele characteristic? What differentiates it from a polygenic characteristic?
What is an example of a multiple allele characteristic?
a. What are the three possible alleles (be sure to use the proper notation) for human blood
type?
b. Which alleles show codominance?
c. Which allele is recessive to the other two?
d. What are all possible genotypes and phenotypes of the ABO gene?
10. In some families, high cholesterol (the inability to get rid of excess cholesterol) is inherited.
What type of dominance pattern is shown? What level of cholesterol would an individual,
heterozygous for this trait, have?
11. Some families have a “baldness” allele that is X-linked. Is it possible for a female offspring to
show this phenotype? Create a Punnett square that provides evidence to support your answer.
12. What is the purpose of a genetic counselor? What tools can a genetic counselor use to answer
questions?
13. Can we currently cure genetic diseases? What would be required to cure a disease?
14. Provide three examples of treating (not curing) a genetic disease.
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Review for Genetics - H (use problem sets too!)
15. What is epistasis? How does it work? Be able to identify the outcomes of a Labrador (or similar)
breeding
16. Explain the color patterns that occur in cats carrying orange/black gene as a result of Xinactivation.
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