Question

Failure of separation of sister chromatids is

• A. Fusion
• B. Nondisjunction
• C. Complementation
• D. Interference

Answer 1

The correct option is B Nondisjunction

There are three forms of nondisjunction: failure of a pair of homologous chromosomes to separate in meiosis I, failure of sister chromatids to separate during meiosis II, and failure of sister chromatids to separate during mitosis. Nondisjunction results in daughter cells with abnormal chromosome numbers (aneuploidy). Nondisjunction causes errors in chromosome number, such as trisomy 21 (Down syndrome) and monosomy X (Turner syndrome).

So, the correct answer is 'Nondisjunction'.