Non-Mendelian Genetics

Flashcards summarizing key terms and concepts related to non-Mendelian genetics, their definitions, and provide a basis for study.

Non-Mendelian Genetics

Genetics that do not follow Mendel's laws of inheritance, including traits with varying degrees of dominance, multiple gene interactions, or traits on sex chromosomes.

Complete dominance

A type of dominance where one allele completely masks the effect of another allele.

Incomplete dominance

A situation in which neither allele is fully dominant, resulting in a phenotype that is a blend of the parental traits.

Codominance

A situation in which both alleles are fully expressed in the phenotype of the heterozygote.

Multiple alleles

A condition in which a gene has more than two alleles that can exist within a population.

Epistasis

A genetic interaction where the expression of one gene is affected by another gene.

Polygenic inheritance

A trait controlled by two or more genes, resulting in a wide range of phenotypes.

Sex-linked genes

Genes located on sex chromosomes, often leading to specific inheritance patterns.

X-linked genes

Genes located on the X chromosome; typically have different inheritance patterns in males and females.

Y-linked genes

Genes located on the Y chromosome, usually relating to male-specific traits or conditions.

Hemizygous

Having only one allele for a gene in an otherwise diploid cell, typical in males for X-linked genes.

Genetic recombination

The process of producing new combinations of genes in offspring; can result from crossing over during meiosis.

Linked genes

Genes that are located close together on the same chromosome and are inherited together.

Crossing over

The exchange of chromosome segments between homologous chromosomes during meiosis, leading to genetic diversity.

Linkage map

A genetic map based on recombination frequencies, showing the relative positions of genes on a chromosome.

Non-nuclear DNA

DNA located outside of the nucleus, such as mitochondrial and chloroplast DNA, often inherited maternally.

Chi-square test

A statistical method used to determine if there is a significant difference between observed and expected data.

Degrees of freedom

A value used in statistical tests that indicates the number of independent values or quantities that can vary.

Environmental factors

External conditions that can affect gene expression and lead to variations in phenotype.

Nondisjunction

The failure of chromosomes to separate properly during cell division, leading to an abnormal number of chromosomes.

Tay-Sachs disease

An autosomal recessive disorder caused by a mutation in the HEXA gene, leading to nerve cell degeneration.

Sickle cell anemia

An autosomal recessive disorder caused by a mutation in the HBB gene, resulting in sickle-shaped red blood cells.

Down Syndrome

A genetic disorder caused by the presence of an extra copy of chromosome 21, also known as trisomy 21.