Question

what results from the fertilization of a gamete with an extra chromosome?
trisomy
tetrasomy
monosomy
aneuploidy

Explanation:

• Trisomy occurs when a gamete with an extra chromosome (n + 1) fuses with a normal gamete (n) during fertilization, resulting in a zygote with 2n + 1 chromosomes (three copies of one chromosome).
• Tetrasomy is having four copies of a chromosome, not from a single extra in a gamete.
• Monosomy is having one copy of a chromosome (from a gamete missing a chromosome).
• Aneuploidy is a general term for abnormal chromosome number, but trisomy is the specific result here.

Answer:

A. trisomy