Chapter Fifteen: Ploidy Flashcards
many plants and some animals can tolerate having multiple ___
chromosome sets
more than two sets of chromosomes
polyploidy
three sets of chromosomes
triploidy
complete chromosome set
euploid
missing one or more chromosomes from a set, or have extra chromosomes
aneuploid
calculation for euploidy
2n
an individual lacking one chromosome
monosomy
an individual with one extra chromosome
trisomy
calculation for nullisomy
2n-2
calculation for monosomy
2n-1
calculation for trisomy
2n+1
aneuploidy usually results in ___ or ___
multiple abnormalities or lethality
autosomal monosomy is usually ___
lethal
most trisomies are ___, a few result in ___
lethal
characteristic syndromes
sex chromosome aneuploidy is ___ due to ___
tolerated
X-chromosome inactivation
___ of births have some sort of genetic anomaly
0.4% (1/250)
phenotype of X-chromosome aneuploidy is largely due to ___ genes
pseudoautosomal (PAR)
X-chromosome aneuploidy causes ___
infertility
aneuploidy is caused by ___
nondisjunction
nondisjunction is the failure of chromosomes to ___
segregate normally
when can nondisjunction occur
meiosis I, meiosis II, and mitosis
failure of sister chromatids to separate during anaphase of mitosis
mitotic nondisjunction
lagging chromatid that is not pulled to either spindle pole at mitotic anaphase
chromosome loss
true or false: nondisjunction can occur in meiosis I, meiosis II, and mitosis
true
aneuploid cells can survive and undergo ___, producing ___
further rounds of mitosis
clones of aneuploid cells