Biology / Unit 6 Bio 1191 short lesson, about 20 seconds
Human Trisomy as a Chromosomal-Disorder Example
Captions available
The idea
Trisomy 21, an extra copy of chromosome 21 from nondisjunction, is the most common human chromosomal trisomy compatible with survival to birth.
In practice
A karyotype showing three copies of chromosome 21 instead of two, rather than any single symptom, is what confirms trisomy 21.
Where people slip
This entry names a chromosome count, not a diagnosis or a health recommendation — no viewer's genetics is addressed.
Your place on the trail
Every lesson rests on earlier ones and opens later ones. Tap any to jump.
Builds on
Unlocks
- Nothing yet depends on this.
Something wrong in this lesson? Flag it · Sources for Biology