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Home Q & A Board Science-Related Homework Help Psychology Developmental Psychology
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genderma genderma
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9 years ago
In about 95% of Down syndrome cases, the extra 21st chromosome exists because
A) of a duplication error during mitosis.
B) of injury that occurs during amniocentesis.
C) the zygote becomes separated and divides into two zygotes.
D) the 21st pair of chromosomes did not separate properly when the egg was formed.
Textbook 
The World of Children

The World of Children


Edition: 3rd
Author:
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yariyari
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9 years ago
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genderma Author
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#2
9 years ago
This is correct! Thank you again.
wrote...
#3
9 years ago
Thanks for the update.
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