Chapter 4 Sex Linked Flashcards
The mixing of genomes via meiosis and fusion of gametes, provides essential genetic variation
Sexual Reproduction
A species in which either male or female structures are present in each individual
Dioecious Species
A species in which both male and female reproductive structures are present in each individual
Monoecious Species
Individuals that contain both male and female sex organs
Hermaphrodites
The mechanism by which the sexual phenotype of an individual is established in a given species
Sex Determination
A chromosome involved with determining the sex of an individual
Sex Chromosome
A chromosome not involved with determining the sex of an individual
Autosome
Sex determined at fertilization and is the presence of chromosomes characteristic of each sex
Chromosomal Sex
The internal and external morphology of each sex, results from differences in gene expression
Phenotypic Sex
The sex-determining system in which females are XX and males are XY, found in many insects, amphibians, reptiles, mammals, and some fish
XX-XY System
The sex-determining system in which females are ZW and males are ZZ, found in butterflies, birds, some reptiles, some fish, and amphibians
ZZ-ZW System
Having sex chromosomes that do not differ in morphology (having two of the same type of sex chromosome)
Homogametic
Having sex chromosomes that differ in morphology (having two different kinds of sex chromosomes)
Heterogametic
An individual who has one of a chromosome instead of two, often used to refer to X linked traits in males because males only have one X chromosome
Hemizygous
The two small regions of homology between the X and Y chromosomes that allow homologous pairing and recombination of the X and Y chromosomes during meiosis, crossing over at these locations can affect the inheritance of sex-linked genes
Pseudoautosomal Regions (PAR1 and PAR2)
A single gene on the Y chromosome on which sex determination depends, is a transcription factor needed for male-specific gene expression
SRY Gene
A human disorder resulting from aneuploidy of sex chromosomes (XO) and occurs in 1/3000 female births
Turner Syndrome
A human disorder resulting from the aneuploidy of sex chromosomes (XXY, XXXY, XXXXY, or XXYY) occurs in 1/1000 male births
Klinefelter Syndrome
A condition caused in XY females by mutations in the SRY gene and in XX males by translocations of part of the Y chromosome to an autosome
Sex Reversal
A condition found in XY females caused by a mutation in an X linked gene that encodes androgen receptor
Androgen-Insensitivity Syndrome
A feature of Drosophila that determines the gender based on the ratio of the number of X chromosomes to the number of sets of autosomes, flies with an X/A ratio of 1.0 are females, flies with a, X/A ratio of 0.5 are males
X-to-Autosome Ratio (X/A Ratio)
