Question

4 what is the name of the chromosomal condition that is the result of an error in meiosis, causing a human to have three copies of chromosome 21? turner syndrome down syndrome edwards syndrome patau syndrome

Explanation:

Turner syndrome is a condition where females have only one X - chromosome. Down syndrome is caused by an extra copy of chromosome 21. Edwards syndrome is due to an extra copy of chromosome 18. Patau syndrome is caused by an extra copy of chromosome 13. The condition with three copies of chromosome 21 is Down syndrome.

Answer:

Down syndrome