Chapter #4 Sex Determination and Chromosomes

These flashcards cover key vocabulary and concepts from the lecture on sex determination and sex chromosomes in various species.

Sex Determination

The mechanism by which an individual develops into a female or male.

Sex Chromosomes

Chromosomes that differ between males and females; in humans, these are X and Y.

Heterogametic Sex

The sex with two different sex chromosomes, such as XY in males.

Homogametic Sex

The sex with two of the same sex chromosomes, such as XX in females.

SRY Gene

The gene on the Y chromosome responsible for male development.

X-0 Sex Determination

A system where males have one X chromosome and females have two X chromosomes, commonly found in some insects.

Z-W Sex Determination

Found in birds where males are Z-Z and females are Z-W.

Haplodiploid Sex Determination

A system where sex is determined by the number of chromosome sets, seen in bees and ants.

Temperature-Dependent Sex Determination

A mechanism found in some reptiles where temperature influences sex, as seen in American alligators.

Dosage Compensation

The mechanism that equalizes the expression of X chromosome genes between sexes.

X-Chromosome Inactivation

A process where one of the X chromosomes in female mammals is inactivated to ensure dosage compensation.

Barr Body

The condensed structure of an inactive X chromosome in female mammals.

Pedigree Analysis

A method used to track inheritance patterns of traits in humans.

X-linked Inheritance

Inheritance pattern where genes are located on the X chromosome.

Testcross

Crossing a phenotypically dominant individual with a recessive individual to observe inheritance.

Reciprocal Crosses

Crosses that differ in which sex carries a trait, used to determine X-linked traits.

Duchenne Muscular Dystrophy

An X-linked recessive disorder characterized by muscle degeneration.

Cystic Fibrosis

A recessive genetic disorder caused by mutations in the CFTR gene, leading to various health issues.