The condition in which there are three copies of the a chromosomes type instead of the normal two is called

Trisomy

Explanation:

A trisomy is a type of polysomy (presence of three or more copies of the chromosome rather than the expected two copies) in which there are three copies of a particular chromosome, instead of the normal two. A trisomy is a also a genetic disorder and a type of aneuploidy (an abnormal number of chromosomes either an increase or a decrease). Examples include trisomy 21 (Down syndrome), trisomy 18 (Edward syndrome), trisomy 13 (Patau syndrome)

The condition in which there are three copies of the a chromosomes type instead of the normal two is called trisomy and an example of such individual suffers from a disorder called down syndrome

Explanation:

the element that provides strength to the exoskeletons of clams and oysters is phosphorus. this is so because calcium carbonate is the main component in the shells.

explanation:

atp is used for energy.