What is the term for an abnormal number of chromosomes in a cell, with embryos carrying aneuploidies most often not viable?

What is the term for an abnormal number of chromosomes in a cell, with embryos carrying aneuploidies most often not viable?

• A. Polyploidy
• B. Monosomy
• C. Aneuploidy
• D. Diploidy

Answer: (C)

An abnormal number of chromosomes in a cell is called aneuploidy. It means there are too few or too many chromosomes compared with the normal diploid set. This differs from polyploidy, where whole additional sets of chromosomes are present, and from diploidy, which is the normal two sets. Aneuploidy often arises from errors in chromosome separation during cell division (nondisjunction), and embryos with this imbalance are usually not viable, leading to miscarriage or early developmental failure. Some specific aneuploidies, like trisomy 21, can be viable but are still abnormal.

An abnormal number of chromosomes in a cell is called aneuploidy. It means there are too few or too many chromosomes compared with the normal diploid set. This differs from polyploidy, where whole additional sets of chromosomes are present, and from diploidy, which is the normal two sets. Aneuploidy often arises from errors in chromosome separation during cell division (nondisjunction), and embryos with this imbalance are usually not viable, leading to miscarriage or early developmental failure. Some specific aneuploidies, like trisomy 21, can be viable but are still abnormal.