15.1 Pedigrees

Front

What is a pedigree?

Back

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

Front

What does it mean if an allele is dominant?

Back

A dominant allele is one that expresses its trait even when only one copy is present in the genotype (heterozygous condition).

Front

What does it mean if an allele is recessive?

Back

A recessive allele is one that only expresses its trait when two copies are present in the genotype (homozygous condition).

Front

What is the genotype of an individual with a dominant phenotype?

Back

The genotype can be either homozygous dominant (RR) or heterozygous (Rr).

Front

How can you determine if an individual is homozygous or heterozygous?

Back

You can determine this by examining the phenotypes of their offspring; if any offspring express the recessive trait, the individual must be heterozygous.

Front

What is the significance of the F1 generation in genetics?

Back

The F1 generation is the first filial generation, which is the result of a cross between two parental (P) generations.

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What is the significance of the F2 generation in genetics?

Back

The F2 generation is the second filial generation, produced by crossing two F1 individuals, and it shows the segregation of alleles.

Front

What does it mean for a trait to be sex-linked?

Back

A sex-linked trait is one that is associated with a gene that is located on a sex chromosome, often affecting males and females differently.

Front

What is a carrier in genetics?

Back

A carrier is an individual who has one copy of a recessive allele for a trait but does not express the trait phenotypically.

Front

What is the purpose of a Punnett square?

Back

A Punnett square is a tool used to predict the genotypes and phenotypes of offspring from a genetic cross.