aneuploidy

Examples of aneuploidy in the following topics:

• Disorders in Chromosome Number

  • Aneuploidy, an abnormal number of chromosomes in a cell, is caused by nondisjunction, or the failure of chromosomes to separate at meiosis.
  • Of all of the chromosomal disorders, abnormalities in chromosome number are the most obviously identifiable from a karyotype and are referred to as aneuploidy.
  • Aneuploidy is a condition in which one or more chromosomes are present in extra copies or are deficient in number, but not a complete set.
  • Aneuploidy often results in serious problems such as Turner syndrome, a monosomy in which females may contain all or part of an X chromosome.

• Sympatric Speciation

  • However, sometimes the pairs separate and the end cell product has too many or too few individual chromosomes in a condition called aneuploidy .
  • Aneuploidy results when the gametes have too many or too few chromosomes due to nondisjunction during meiosis.

• Gene Duplications and Divergence

  • Aneuploidy occurs when nondisjunction at a single chromosome results in an abnormal number of chromosomes.
  • Aneuploidy is often harmful and in mammals regularly leads to spontaneous abortions.
  • Aneuploidy often alters gene dosage in ways that are detrimental to the organism and therefore, will not likely spread through populations.