Question

What is the formula for trisomy?

Options

• 2n − 2

• 2n − 1

• 2n + 2

• 2n + 1

Answer 1

Trisomy is represented by the formula 2n + 1, indicating the presence of three copies of a particular chromosome instead of the normal two. This results in 47 chromosomes in humans. Trisomy conditions show variable viability depending on which chromosome is affected; autosomal trisomies 13, 18, and 21 are the most commonly observed in live births.