Patterns of Inheritance and Genetics

A collection of vocabulary flashcards covering basic genetics, Mendelian laws, Punnett squares, non-Mendelian inheritance patterns, and human genetic disorders based on the lecture notes.

Genetics

The scientific study of heredity and hereditary variation.

Heredity

The transmission of traits from one generation to the next.

Gregor Mendel

Known as the "Father of Modern Genetics," he performed crossing experiments using different varieties of garden peas.

Hybridization

Also known as crossing, it is the process of transferring pollen from the stamen of one flower to the carpel of another, such as Mendel's work with purple and white flowers.

Pisum sativum

The scientific name for the garden pea used by Mendel due to its short generation time, variety, and ability to self-pollinate.

Locus

The specific location of a DNA sequence of a gene on a chromosome.

Homozygous

Describes an individual carrying identical alleles for a gene.

Heterozygous

Describes an individual carrying two different alleles of a gene.

Genotype

The particular set of alleles that an individual carries.

Phenotype

The observable traits of an individual, such as flower color.

Dominant Allele

An allele $(A)$ whose effect masks that of a recessive $(a)$ allele paired with it.

Hybrids

Heterozygous offspring resulting from a cross between two homozygous parents.

P Generation

The parental generation.

F1 Generation

The first filial generation, resulting from crossing two parents with contrasting traits.

F2 Generation

The second filial generation resulting from crossing two F1 individuals.

Punnett Square

A grid used to predict the genotypic and phenotypic outcome of a cross.

Monohybrid Cross

A cross between individuals that are heterozygous for the same characteristic, usually starting from a cross between two true-breeding varieties.

Law of Segregation

Mendel's First Law of Genetics stating that the paired unit factors (alleles) separate randomly during the formation of gametes so that each gamete receives one or the other with equal likelihood.

Dihybrid Cross

A cross where the parents are heterozygous for two traits, resulting in a phenotypic inheritance pattern of $9:3:3:1$ among the F2 offspring.

Law of Independent Assortment

Mendel's Second Law of Genetics stating that during meiosis, members of a pair of genes on homologous chromosomes get distributed into gametes independently of other gene pairs.

Testcross

A method to determine unknown genotypes by crossing an individual with a dominant phenotype with a homozygous recessive individual.

Codominance

An inheritance pattern where both alleles are expressed, such as in AB blood type where both Carbohydrate A and Carbohydrate B are present on red blood cells.

Incomplete Dominance

An inheritance pattern where the heterozygous phenotype is an intermediate between the two homozygous parents, such as pink flowers resulting from red and white snapdragons.

Polygenic Inheritance

The additive effects of two or more genes on a single phenotypic character, resulting in continuous variation like human skin color, height, and eye color.

Sex-linked Gene

A gene located on a sex chromosome; most are found on the X chromosome, including those for red-green colorblindness and hemophilia.

Hemophilia

A sex-linked recessive trait characterized by a long history in the descendants of Queen Victoria.

Albinism

An autosomal recessive disorder characterized by a lack of pigment in skin, hair, and eyes.

Phenylketonuria (PKU)

An autosomal recessive disorder involving the accumulation of phenylalanine in the blood; products with Aspartame often contain a warning for this condition.

Achondroplasia

An autosomal dominant disorder that results in dwarfism.

Huntington's Disease

An autosomal dominant disorder occurring in middle age characterized by uncontrollable movements and cognitive impairments.