Down’s syndrome results from people having an extra copy of chromosome 21 in their cells as shown here. people with down’s syndrome have both a lower iq and a shorter life expectancy than those without down’s syndrome. this is an example of

The answer is trisomy 21.

Trisomy 21 is a condition in which an extra copy of chromosome 21 is present. Instead of two chromosomes 21 in a cell, there are three chromosomes. This is a consequence of a failure of chromosome 21 to separate during the gamete development. Thus, an egg cell or a sperm cell will have two instead of one chromosome 21 and after a cross with normal gamete cell, a zygote will have three chromosomes 21.

The virus is considered to be are living item since they have hereditary material dnas or rnas. they can imitate and change. they respond to boosts, for example, radiation, chemicals, and warmth. they have antigenic properties. they are proficient to duplicate with a same hereditary constituent.