Mendelian Genetics and Inheritance Patterns Flashcards

Vocabulary flashcards covering Mendel's laws, probability rules, human genetic inheritance, and non-Mendelian extensions from Chapter 14.

Law of Segregation

Mendel's law stating that the two alleles of a gene segregate (separate) during meiosis and gamete formation, resulting in each sperm or egg carrying only one allele of each pair.

Alleles

Alternative forms of a gene that determine inherited traits.

Homozygotes

Organisms that have identical alleles of a given gene and are therefore true-breeding.

Heterozygotes

Organisms that have two different alleles for a given gene, where the expression of the dominant allele masks the phenotypic effect of the recessive allele.

Law of Independent Assortment

Mendel's law stating that the pair of alleles for a given gene segregates into gametes independently of the pair of alleles for any other gene.

Dihybrids

Individuals that are heterozygous for two genes.

Multiplication Rule

A probability rule stating that the probability of two or more independent events occurring together is equal to the product of their individual probabilities.

Addition Rule

A probability rule stating that the probability of an event that can occur in two or more independent, mutually exclusive ways is equal to the sum of their individual probabilities.

Multifactorial Characters

Polygenic characters that are also influenced by unique environmental factors, affecting overall phenotype.

Heterozygous Carriers

Phenotypically normal individuals who carry one copy of a recessive allele for a genetic disorder.

Amniocentesis

A medical procedure used during pregnancy to diagnose whether a suspected genetic disorder is present in a fetus.

Chorionic Villus Sampling

A diagnostic testing method used during pregnancy to determine if a fetus has a specific genetic disorder.

Formula for Gamete Types

$2^n$, where $n$ is the number of gene loci that are heterozygous.

Hemochromatosis

An inherited disease caused by a recessive allele.

Alkaptonuria

An inherited biochemical disorder caused by a recessive allele in which affected individuals cannot metabolize alkapton, leading to colored urine and stained body tissues.

Incomplete Dominance

An inheritance pattern describing the relationship between two alleles of a single gene where heterozygotes display an intermediate phenotype between homozygous phenotypes.

Codominance

An inheritance pattern in which both alleles are fully and distinctly expressed in the phenotype of heterozygotes, such as in the ABO blood group alleles $I^A$ and $I^B$.

Epistasis

A phenotypic relationship where one gene alters or masks the phenotypic expression of a second gene.

Zebrafish (Danio rerio)

A popular model organism characterized by transparent embryos and large offspring numbers, used to study genetic mutations such as gol (golden) and leo (leopard).