Applied Genetics with Pedigrees Review

Front

What is a pedigree chart?

Back

A pedigree chart is a diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors, used to analyze the inheritance of traits.

Front

What does it mean for a disorder to be recessive?

Back

A recessive disorder requires two copies of the recessive allele (hh) for the individual to express the disorder; if only one copy is present (Hh), the individual is a carrier but does not show symptoms.

Front

What is codominance in genetics?

Back

Codominance is a form of inheritance where both alleles in a heterozygote are fully expressed, resulting in a phenotype that is neither dominant nor recessive, such as speckled feathers in chickens.

Front

What is an example of an X-linked disorder?

Back

Hemophilia is an example of an X-linked disorder, which primarily affects males and is caused by a recessive allele on the X chromosome.

Front

What is the genotype of a female carrier for a recessive disorder?

Back

The genotype of a female carrier for a recessive disorder is X^H X^h, where X^H is the normal allele and X^h is the recessive allele.

Front

What is incomplete dominance?

Back

Incomplete dominance is a genetic situation in which one allele does not completely dominate another allele, resulting in a phenotype that is a blend of the two.

Front

What is the expected phenotype ratio in a monohybrid cross?

Back

In a monohybrid cross, the expected phenotype ratio for dominant to recessive traits is typically 3:1.

Front

How do you determine the genotype of an individual from a pedigree?

Back

To determine the genotype of an individual from a pedigree, analyze the phenotypes of the individual and their relatives, considering the inheritance patterns of the traits.

Front

What is the significance of a carrier in genetics?

Back

A carrier is an individual who has one copy of a recessive allele and does not show symptoms of the disorder but can pass the allele to offspring.

Front

What is the probability of a child inheriting a recessive disorder if both parents are carriers?

Back

If both parents are carriers (Hh), there is a 25% chance that their child will inherit the recessive disorder (hh).