Answer:
The correct answer is 1. Trisomy 21
Explanation:
Trisomy 21 is a genetic disorder that is also known as Downs syndrome in which an extra chromosome is inherited by the baby from the parent.
In this syndrome instead of the usual pair, three chromosome is present at position 21. Children with this syndrome developmental and mental problems like distinctive facial features, Heart, kidney and thyroid issues, Heart, kidney and thyroid issues, short neck with extra skin in the back of the neck, a depressed nasal bridge.
Early the life expectancy of people with down syndrome was 25 years but now it has increased to 60 years.