Chapter 14 (Mendel and the Gene Idea) learning objectives
- List several features of Mendel’s methods that
contributed to his success.
- List the four components of Mendel’s hypothesis
that led him to deduce the law of segregation.
- What is the law of segregation?
- Use a Punnett square to predict the results of a
monohybrid cross and state the phenotypic and genotypic ratios of the F1
and F2 generation.
- Distinguish between genotype and phenotype;
heterozygous and homozygous; dominant and recessive.
- Explain how a testcross can be used to determine if a
dominant phenotype is homozygous or heterozygous.
- Define random event, and explain why it is
significant that allele segregation during meiosis and fusion of gametes
at fertilization are random events.
- Use the rule of multiplication to calculate the
probability that a particular F2 individual will be homozygous
recessive or homozygous dominant.
- Given a Mendelian cross, use the rule of addition to
calculate the probability a particular F2 individual will be
heterozygous.
- What is the law of independent assortment?
- Use the Punnett square to predict the results of a
dihybrid cross and state the genotypic and phenotypic ratios of the
offspring.
- Understand incomplete dominance.
- Explain how the phenotypic expression of the heterozygote
is affected by complete dominance, incomplete dominance, and codominance.
- Describe the inheritance of the ABO blood system and
explain why the A and B alleles are said to be codominant.
- Define and give examples of pleiotropy.
- Explain what is meant by “one gene is epistatic
to another.”
- Explain how epistasis affects the phenotypic ratio of
a dihybrid cross.
- Describe a simple model for polygenic inheritance,
and explain why most polygenic characters are described in quantitative
terms.
- Describe how environmental factors can influence the
phenotypic expression of a character.
- Given a simple family pedigree, deduce the genotypes
of some of the family members.
- Describe the inheritance and expression of cystic
fibrosis, Tay-Sachs disease, and sickle-cell anemia.
- Give an example of a lethal dominant gene in humans
and explain how it can escape elimination in a population.
- Explain how carrier recognition, fetal testing and
newborn screening can be used in genetic screening and counseling.