Question

Why older mothers are more likely to have children with Down syndrome: eggs formed before birth, but stuck in _________ __ until just before ovulation. Increase in age = more time for components of the _______, etc. to _________.

a) Primordial follicles; egg; mature
b) Secondary oocytes; ovary; deteriorate
c) Prophase I; follicle; accumulate
d) Prophase I, spindle, breakdown

Answer 1

Older mothers are more likely to have children with Down syndrome because as women age, their eggs have more time for components to deteriorate, increasing the risk of chromosomal abnormalities.

Step-by-step explanation:

As women age, their eggs are more likely to have chromosomal abnormalities, including Down syndrome. This is because during a woman's lifetime, her eggs are formed before birth and remain stuck in prophase I until just before ovulation. The longer the eggs are held in this phase, the more time there is for components of the eggs to deteriorate, increasing the risk of chromosomal abnormalities.