Sex Chromosomes & the Chromosomal Theory of Inheritance

A set of flashcards covering key concepts, definitions, and notable figures related to sex chromosomes and the Chromosomal Theory of Inheritance.

Sex Chromosome

A type of chromosome involved in sex determination; humans have two sex chromosomes, X and Y.

Autosome

Any chromosome that is not a sex chromosome.

Mendelian Segregation

The segregation of sex chromosomes during meiosis resulting in a 1:1 ratio of X and Y carrying sperm.

X-linked Inheritance

Pattern of inheritance for genes located on the X chromosome, often affecting males more than females.

X Inactivation

The process by which one of the X chromosomes in XX females is randomly inactivated.

Nondisjunction

Failure of homologous chromosomes to separate properly during meiosis, leading to an abnormal number of sex chromosomes.

Dosage Compensation

Mechanism to equalize the expression of X-linked genes between XX females and XY males.

Thomas Hunt Morgan

An American geneticist who discovered the chromosomal theory of inheritance and worked with Drosophila as a model organism.

Lilian Vaughan Morgan

A geneticist who discovered exceptional flies with unusual chromosome composition and contributed to the understanding of X-linked traits.

Recessive Alleles

Alleles that are only expressed in the homozygous condition; in X-linked cases, often expressed in males due to having only one X chromosome.