Chapter 7 - Sex Determination and Sex Chromosomes Flashcards
(28 cards)
dioecious
plant species in which each individual is only one sex
monecious
plant species in which individuals are both sexes
gonochoric
animal species in which each individual is only one sex
diploid _____ produce ____ by meiosis
sporophytes; spores
haploid _____ produce _____ by mitosis
gametophytes; gametes
protenor mode
XX/XO
XO= male
lygaeus mode
XX/XY
XY= male
homogametic
sex that has one type of sex chromosome
heterogametic
two different types of sex chromosomes
monosomy
missing a chromosome
2n-1
trisomy
have an extra chromosome
2n+1
aneuploidy
variation in chromosome number
nondisjunction
failure of paired homologous chromosomes to separate during meiosis
klinefelter syndrome
XXY (extra X)
poor development of male characteristics
Turner syndrome
X (missing)
poor ovarian development, short stature
pseudoautosomal region (PAR)
where X & Y interact in meiosis
male specific region (MSY)
genes specific to Y
sex determining region Y (SRY)
controls male sexual development, encodes TDF
testis-determining factor
causes formation of testes
regions of MSY
x-transposed region, x-degenerative region, ampliconic region
primary human sex ratio
1:1
males conceived/females conceived
secondary human sex ratio
favors male because it is males born/females born
tertiary human sex ratio
1:1
age 20+ years
barr body
inactivation of one X in females
