Sally is born with 47 chromosomes instead of the usual 46. Sally's chances of survival are _____.
A) 1 in 16
B) 1 in 166
C) 1 in 2,166
D) 1 in 20,166

Question

Quizplus · Accepted Answer

Sally most likely has Down syndrome, which is caused by an extra chromosome 21. Down syndrome occurs in about 1 in every 166 births, so the chances of Sally's survival would also be approximately 1 in 166. Option A is incorrect as it assumes that 47 chromosomes is a specific and known disorder, which it is not. Option C and D are highly unlikely as they assume very rare and specific conditions that are not related to the given information about Sally's additional chromosome.

Sally Is Born with 47 Chromosomes Instead of the Usual