| Gregor
Mendel’s Discoveries |
| 1. |
Explain how Mendel’s
particulate mechanism differed from the blending theory of
inheritance. |
| 2. |
Define the following
terms: true-breeding, hybridization, monohybrid cross, P
generation, F1 generation, and F2
generation. |
| 3. |
List and explain the four
components of Mendel’s hypothesis that led him to deduce the law
of segregation. |
| 4. |
Use a Punnett square to
predict the results of a monohybrid cross, stating the phenotypic
and genotypic ratios of the F2 generation. |
| 5. |
Distinguish between the
following pairs of terms: dominant and recessive; heterozygous
and homozygous; genotype and phenotype. |
| 6. |
Explain how a testcross
can be used to determine if an individual with the dominant
phenotype is homozygous or heterozygous. |
| 7. |
Use a Punnett square to
predict the results of a dihybrid cross and state the phenotypic
and genotypic ratios of the F2 generation. |
| 8. |
State Mendel’s law of
independent assortment and describe how this law can be explained
by the behavior of chromosomes during meiosis. |
| 9. |
Use the rule of
multiplication to calculate the probability that a particular F2
individual will be homozygous recessive or dominant. |
| 10. |
Given a Mendelian cross,
use the rule of addition to calculate the probability that a
particular F2 individual will be heterozygous. |
| 11. |
Use the laws of
probability to predict, from a trihybrid cross between two
individuals that are heterozygous for all three traits, what
expected proportion of the offspring would be:
a. homozygous dominant for the three traits
b. heterozygous for all three traits
c. homozygous recessive for two specific traits and heterozygous
for the third |
| 12. |
Explain why it is
important that Mendel used large sample sizes in his studies. |
| |
|
| |
Extending
Mendelian Genetics |
| 13. |
Give an example of
incomplete dominance and explain why it does not support the
blending theory of inheritance. |
| 14. |
Explain how phenotypic
expression of the heterozygote differs with complete dominance,
incomplete dominance, and codominance. |
| 15. |
Explain why Tay-Sachs
disease is considered recessive at the organismal level but
codominant at the molecular level. |
| 16. |
Explain why genetic
dominance does not mean that a dominant allele subdues a recessive
allele. Illustrate your explanation with the use of round versus
wrinkled pea seed shape. |
| 17. |
Explain why dominant
alleles are not necessarily more common in a population.
Illustrate your explanation with an example. |
| 18. |
Describe the inheritance
of the ABO blood system and explain why the IA and IB
alleles are said to be codominant. |
| 19. |
Define and give examples
of pleiotropy and epistasis. |
| 20. |
Describe a simple model
for polygenic inheritance and explain why most polygenic
characters are described in quantitative terms. |
| 21. |
Describe how
environmental conditions can influence the phenotypic expression
of a character. Explain what is meant by “a norm of reaction.” |
| 22. |
Distinguish between the
specific and broad interpretations of the terms phenotype
and genotype. |
| |
|
| |
Mendelian
Inheritance in Humans |
| 23. |
Explain why studies of
human inheritance are not as easily conducted as Mendel’s work
with his peas. |
| 24. |
Given a simple family
pedigree, deduce the genotypes for some of the family members. |
| 25. |
Explain how a lethal
recessive allele can be maintained in a population. |
| 26. |
Describe the inheritance
and expression of cystic fibrosis, Tay-Sachs disease, and
sickle-cell disease. |
| 27. |
Explain why lethal
dominant genes are much rarer than lethal recessive genes. |
| 28. |
Give an example of a
late-acting lethal dominant gene in humans and explain how it can
escape elimination by natural selection. |
| 29. |
Define and give examples
of multifactorial disorders in humans. |
| 30. |
Explain how carrier
recognition, fetal testing, and newborn screening can be used in
genetic screening and counseling. |
