Chapter 9-Genes and Inheritance

These flashcards cover key vocabulary terms and concepts related to the topic of genes and inheritance, including definitions and explanations relevant to the chapter.

Gene

A segment of DNA that codes for a specific trait.

Allele

A variant form of a gene that can exist at a particular locus.

Dominant

An allele that expresses its phenotype even in the presence of a recessive allele.

Recessive

An allele that expresses its phenotype only when two copies are present.

Homozygous

An organism with two identical alleles for a trait.

Heterozygous

An organism with two different alleles for a trait.

Genotype

The genetic constitution of an individual, represented by alleles.

Phenotype

The observable physical or biochemical characteristics of an organism, determined by genotype.

Punnett Square

A grid used to predict the genotypes of offspring from a genetic cross.

Incomplete Dominance

A genetic situation in which one allele does not completely dominate another, resulting in a blending of traits.

Codominance

A genetic situation in which both alleles in a heterozygote are fully expressed.

Multiple Alleles

A situation in which a gene has more than two alleles.

Polygenic Inheritance

A trait controlled by two or more genes.

Pleiotropy

The ability of a single gene to influence multiple traits.

Sex-linked Traits

Traits that are associated with a gene located on a sex chromosome.

Pedigree Analysis

A chart that outlines the inheritance of traits through generations of a family.

Test-Cross

A breeding experiment used to determine the genotype of an individual with a dominant phenotype.

Linked Genes

Genes that are located close to each other on the same chromosome and tend to be inherited together.

Antigen

A substance that induces an immune response, such as the proteins found on the surface of blood cells.

Rh Factor

A protein that can be present on the surface of red blood cells, determining the positive or negative blood type.

Polygenic Trait

A trait controlled by multiple genes.

Environmental Influence

Factors outside of the genetic code that can affect an organism's phenotype.