Teratology Flashcards
fewer than ____ of human zygotes and less than ___ of all pregnancies result in normal, healthy babies
20-30%, half
one of every ___ infants die due to birth defects
5
as the embryo develops it ____ embryonic cellular potency and ____ cellular differentiation
loses, gains
major malformations usually occur during ____
organogenesis (critical period)
embryonic regulation:
internal rearrangements of development schedules, populations of cells which allows the fetus to respond to challenges
most birth defects are caused by:
unknown etiology
developmental plasticity
ability of a single gene to express more than one phenotype based on environmental conditions i.e. alligator eggs
aneuploidy
chromosome number is not a multiple of 23
aneuploidy is typically caused by:
nondisjunction during gametogenesis
Trisomy 18 is known as:
Edward syndrome
Trisomy 13 is known as:
Patau syndrome
Turner syndrome
45 X
Klinefelter syndrome
47 XXY
Cri du chat syndrome
deletion of short arm of chromosome 5
most common structural defect of X chromosome:
isochromosomes, centromere divides transversely instead of longitudinally