in-a-trisomy-21-condition-which-of-the-following-causes-the-extra-copy-of-chromo

Question

In a trisomy 21 condition, which of the following causes the extra copy of chromosome 21?

Accepted Answer

Failure of proper separation of two homologous chromosomes

Answer

A mutation in a specific gene of two homologous chromosomes

Answer

Missing one copy of the homologous chromosomes

Answer

Duplication of the two homologous chromosomes