Sex Determination and Chromosomes

Flashcards for key vocabulary and concepts related to sex determination and chromosomes.

Heterogametic

The sex with dissimilar sex chromosomes (e.g., XY in humans).

Homogametic

The sex with uniform sex chromosomes (e.g., XX in humans).

Dosage Compensation

Mechanisms that balance the expression of X-linked genes between males and females.

Barr Body

Inactivated X chromosome in diploid cells of females, visible during mitotic interphase.

Klinefelter Syndrome

A genetic condition in males characterized by an extra X chromosome (47, XXY).

Turner Syndrome

A genetic condition in females with a missing X chromosome (45, X).

Triplo-X Syndrome

A genetic condition in females with an extra X chromosome (47, XXX).

Temperature-Dependent Sex Determination (TSD)

A mechanism in some reptiles where the sex of the offspring is determined by the incubation temperature.

XY Sex Determination

A mode of genetic sex determination where the presence of a Y chromosome typically indicates male.

XX Sex Determination

A mode of genetic sex determination typically resulting in female offspring.

Lyon Hypothesis

The concept that one X chromosome is randomly inactivated in female mammals during early embryonic development.

Sexual Dimorphism

Differences in physical characteristics between males and females of the same species.

Pseudoautosomal Regions

Regions on sex chromosomes that are involved in pairing and recombination during meiosis.

Euchromatin

A less condensed form of chromatin that contains genes and is actively transcribed.

SRY Gene

The sex-determining region Y gene that codes for the testis-determining factor in males.

Non-disjunction

The failure of chromosomes to separate properly during cell division, leading to an abnormal number of chromosomes.