Pedigrees

What is a carrier in genetics?

• An individual who expresses both dominant and recessive traits.

• An individual who has two copies of a dominant allele (HH).

• An individual who has one copy of a recessive allele and one copy of a dominant allele (Hh) but does not express the recessive trait.

• An individual who has two copies of a recessive allele (hh).

What is a pedigree?

• A diagram that shows the occurrence and appearance of phenotypes of a particular gene or organism and its ancestors.

• A type of genetic mutation that affects an organism's traits.

• A method of breeding animals to enhance specific traits.

• A chart that tracks the geographical distribution of species.

What does it mean if a trait skips generations in a pedigree?

• It indicates that the trait is dominant and expressed in every generation.

• It may indicate that it is a recessive trait, requiring two copies of the allele to be expressed.

• It suggests that the trait is linked to the X chromosome and affects males more than females.

• It means that the trait is influenced by environmental factors rather than genetics.

What is the significance of dominant alleles?

• Dominant alleles can mask the effect of recessive alleles, meaning that only one copy of a dominant allele is needed for the trait to be expressed.

• Dominant alleles are always expressed in the phenotype regardless of the presence of recessive alleles.

• Dominant alleles can only be expressed if two copies are present in the genotype.

• Dominant alleles have no effect on the phenotype if recessive alleles are present.

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

• By analyzing the phenotypes of the individual and their relatives, especially if the trait is recessive.

• By examining the individual's blood type only.

• By looking at the individual's age and health history.

• By counting the number of offspring the individual has.

How many alleles does a person carry for a trait?

• 1 allele

• 2 alleles

• 3 alleles

• 4 alleles

What does homozygous mean?

• Having two identical alleles for a particular gene (e.g., HH or hh).

• Having two different alleles for a particular gene (e.g., Hh).

• Having one allele for a gene that is dominant and one that is recessive.

• Having no alleles for a particular gene.

In a pedigree, how can you identify a carrier?

• A carrier can often be identified if they have offspring that express a recessive trait, while they do not express it themselves.

• A carrier is someone who expresses a dominant trait in their phenotype.

• A carrier can be identified by having no offspring at all.

• A carrier is always affected by the recessive trait.

What does it mean if an individual is homozygous dominant?

• An individual has two copies of the recessive allele (e.g., hh) and will express the recessive trait.

• An individual has one copy of the dominant allele and one copy of the recessive allele (e.g., Hh).

• An individual has two copies of the dominant allele (e.g., HH) and will express the dominant trait.

• An individual has no copies of the dominant allele and will not express any traits.

What is the purpose of a pedigree chart?

• To track the inheritance of traits and genetic disorders through generations of a family.

• To create a family tree without any genetic information.

• To analyze the physical characteristics of individuals in a family.

• To determine the age of family members based on historical records.