HEREDITY MOD 5 Flashcards
What is a Punnett square used for?
A Punnett square is used to predict the genotype and phenotype combinations of offspring from parental alleles.
What is a pedigree chart?
A pedigree chart displays a family tree and shows which members are affected by a genetic trait, often a genetic disease.
What does a circle represent in a pedigree chart?
A circle represents a female in a pedigree chart.
What does a square represent in a pedigree chart?
A square represents a male in a pedigree chart.
What is the difference between autosomal dominant and autosomal recessive inheritance?
Autosomal dominant traits appear in every generation and require at least one affected parent. Autosomal recessive traits often skip generations and can appear in offspring of two unaffected carriers.
What is incomplete dominance?
Incomplete dominance occurs when two alleles blend to create a new phenotype (e.g., red and white flowers producing pink flowers).
What is codominance?
Codominance occurs when both alleles are expressed equally without blending (e.g., red and white coat colors appearing together).
What is sex-linked inheritance?
Sex-linked inheritance refers to traits carried on the sex chromosomes (X or Y), with X-linked traits being more common in males.
What is multiple alleles?
Multiple alleles refer to a gene having more than two possible alleles in a population (e.g., blood type with A, B, and O alleles).
How can you tell if a trait is autosomal or sex-linked using a pedigree?
If a trait appears equally in males and females, it is likely autosomal. If it appears more frequently in one sex, it may be sex-linked.
What is the genotype of a carrier for an autosomal recessive trait?
The genotype of a carrier for an autosomal recessive trait is heterozygous (e.g., Aa).
What is the genotype of an affected individual with an autosomal dominant trait?
The genotype of an affected individual with an autosomal dominant trait is either homozygous dominant (AA) or heterozygous (Aa).
What is the genotype of a male with an X-linked recessive trait?
The genotype of a male with an X-linked recessive trait is XᵃY, where ‘a’ represents the recessive allele.
What is the genotype of a female carrier for an X-linked recessive trait?
The genotype of a female carrier for an X-linked recessive trait is XᴬXᵃ, where ‘A’ is the dominant allele and ‘a’ is the recessive allele.
What does a horizontal line between a circle and square represent in a pedigree?
A horizontal line between a circle and square represents a mating or marriage in a pedigree.
What does a vertical line in a pedigree represent?
A vertical line in a pedigree represents offspring descending from a mating pair.
What is the genotype of an unaffected individual in an autosomal recessive pedigree?
The genotype of an unaffected individual in an autosomal recessive pedigree is either homozygous dominant (AA) or heterozygous (Aa).
What is the genotype of an affected individual in an autosomal dominant pedigree?
The genotype of an affected individual in an autosomal dominant pedigree is either homozygous dominant (AA) or heterozygous (Aa).
What is the genotype of a female with an X-linked dominant trait?
The genotype of a female with an X-linked dominant trait is XᴬXᴬ or XᴬXᵃ, where ‘A’ is the dominant allele.
