Genetics and Inheritance

Vocabulary flashcards to aid understanding of key terms related to genetics and inheritance.

Alleles

Different forms of a gene that can exist at a specific locus.

Gamete

A reproductive cell (sperm or egg) that contains half the genetic information of an organism.

Dominant allele

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

Recessive allele

An allele that expresses its trait only in the absence of a dominant allele.

Genotype

The genetic makeup of an organism, indicating the alleles present.

Phenotype

The observable characteristics of an organism, resulting from the interaction of its genotype with the environment.

Homozygous

An individual with two identical alleles for a given trait.

Heterozygous

An individual with two different alleles for a given trait.

Mendelian inheritance

Inheritance patterns that follow the principles established by Gregor Mendel, including the laws of segregation and independent assortment.

Monohybrid cross

A genetic cross between parents that differ in only one trait.

Dihybrid cross

A genetic cross between parents that differ in two traits.

Punnett square

A diagram used to predict the genotypes and phenotypes of offspring from genetic crosses.

Test cross

A cross between an individual of unknown genotype and a homozygous recessive individual to determine the unknown genotype.

Law of segregation

Mendel's first law stating that two alleles for a trait separate during gamete formation.

Law of independent assortment

Mendel's second law stating that alleles for different traits assort independently of one another during gamete formation.

Sex-linked traits

Traits associated with genes located on sex chromosomes, often showing different patterns of inheritance in males and females.

Multiple alleles

More than two alleles exist for a genetic trait within a population.

Polygenic inheritance

Inheritance pattern of a trait controlled by two or more genes, resulting in a continuous range of phenotypes.

Pedigree

A chart that shows the inheritance of traits across generations in a family.

Gene-chromosome theory

The theory that genes are located on chromosomes and that patterns of inheritance are explained by the behavior of chromosomes during meiosis.

Barr body

An inactivated X chromosome in female mammals, which ensures that only one X chromosome is expressed in each cell.

Incomplete dominance

A type of inheritance where the phenotype of a heterozygote is intermediate between the phenotypes of the two homozygotes.

Co-dominance

A type of inheritance where both alleles in a heterozygote are fully expressed.

Linked genes

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

Recombination frequency

The percentage of recombinant offspring produced in a genetic cross, used to map the distance between genes on a chromosome.