Non-Mendelian Genetics

These flashcards cover key concepts from non-Mendelian genetics, focusing on inheritance patterns, terminology, and sample genetic problems.

What are the two major types of alleles in Mendelian genetics?

Dominant and recessive alleles.

What does 'codominance' mean in genetics?

In codominance, different alleles both express at the same time, such as in ABO blood typing.

What is incomplete dominance?

Incomplete dominance occurs when the phenotype of heterozygotes is intermediate between the two homozygous phenotypes.

What symbol represents inherited traits in a pedigree?

Symbols that represent family relationships and transmission of traits.

How is penetrance defined?

The percentage of individuals with a genotype that express the associated phenotype.

What is expressivity in genetics?

The degree to which the phenotype is expressed; it can vary in severity among individuals.

What is pleiotropy?

When one gene influences multiple traits.

What is epistasis?

Epistasis occurs when one gene's effect is dependent on another gene, affecting the phenotype.

What is phenocopy?

A phenotypic trait that appears inherited but is actually caused by environmental factors.

What is the definition of extranuclear inheritance?

Inheritance of genes located outside the nucleus, such as mitochondrial DNA.

What is the significance of heteroplasmy?

Heteroplasmy is the presence of multiple types of mitochondrial DNA within a single cell.

What does the term 'multiple alleles' refer to?

A situation where a gene has more than two alleles, such as the alleles for blood type.

What is the phenotype of a homozygous recessive individual for a trait?

The individual will express the recessive phenotype.

In terms of hereditary diseases, what is the role of 'lethal genes'?

Certain genotypes can be lethal, meaning they prevent survival.

What does the term 'genetic heterogeneity' signify?

Multiple genes can lead to similar traits or disorders.

What is the significance of codominance observed in blood types?

Both A and B alleles are expressed equally in individuals with AB blood type.

In a pedigree, what do circles represent?

Circles represent female individuals.

In a pedigree, what do squares represent?

Squares represent male individuals.

What is the expected phenotype ratio for a dominant epistatic interaction?

A ratio of 12:3:1.

What does it mean if a trait shows incomplete dominance?

The phenotype of offspring is a blend of both parental traits.

What is meant by the term 'autosomal recessive disorder'?

A disorder that requires two copies of the recessive allele for expression.