Chapter 3 X-dom and rec Flashcards
_______ involves the genetic and biological processes that produce the male and female characteristics of a species
Sex determination
_______ is the presence of chromosome characteristic of each sex and is determined at the moment of fertilization
Chromosomal sex
_______ is the internal and external morphology of each sex, and results from differences in gene expression
phenotypic sex
placental _______ have X and Y chromosomes
mammals
in mammals the presence of the y chromosome signals _______ sex
male
Two small regions of homology, _______ exist between the X and Y chromosomes
Pseudoautosomal regions (PAR1 and PAR2)
Early mammalian embryos have clusters of tissue called _______, which can develop as ovaries or testes
undifferentiated gonads
_______ found on the Y chromosome, is a transcription factor needed for male-specific gene expression
SRY
birds, reptiles, fish, and butterflies use the _______ where homozygous ___ is male and heterozygous is female
Z/W
Z
In drosophila, Females have __ X chromosomes, and males have __ X chromosomes.
The _______ of the X chromosome determines the outcome of a sex
2
1
dosage
Any mechanism that compensates for the difference in number of copies of genes between males and females is called _______
dosage compensation
The inactive X chromosome in mammalian female somatic cells is called a _______
Barr body
Once X inactivation has occurred in a cell, it is _______ in all the descendants of that cell.
permenant
Random X inactivation requires an X-linked gene called _______. The Gene produces large ____ molecules that spread out and cover the chromosome to be inactivated
X-ist
RNA
In X-linked recessive inheritance, females homozygous for the recessive allele or males _______ for it display the recessive phenotype
Hemizygous
