Too Many or Few Chromosomes
Name: Nisha Z.
Date: January 2004
Is it more harmful for a person to have too few or too
If a sperm and egg that unite have a loss of the same chromosome, then that potential individual is
likely not to survive because it will be missing vital information on those chromosomes.
If an individual adult human has a loss of chromosomes in some cells then those cells are likely to
die for lack of needed information--but it totally depends on where in the body those cells are
whether is makes a big difference to the function of the person.
If a fertilized egg has too many chromosomes, the individual can in some instances develop but may
have problems in functioning. For instance, certain duplications of chromosomes result in diseases
that impair cognitive function and the development of the heart.
If an individual adult human has a gain of chromosome in some cells then those cells are likely to
malfunction and maybe die. This could be worse than outright dying if other normal cells would fill
in for the dead ones.
Jeannine M. Durdik
Associate Professor of Biological Sciences
Either one for humans is typically very bad...the sex chromosomes are a
little less damaging when there is an extra copy.
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Update: June 2012