Question

154. When the chromosome number of a given
organism has one additional chromosome in
one of the homologous pairs, the addition is
known as
a) Trisomy
b) Monosomy
c) Polyploidy
d) nullisomy​

Answer 1

Answer:

(a)trisomy

Explanation:.

trisomy-chromosomal disorder characterized by an additional chromosome, so the person has 47 instead of 46. Down syndrome, Edward syndrome and Patau syndrome are the most common forms of trisomy.

Monosomy--- is a form of aneuploidy with the presence of only one chromosome from a pair.

Polyploidy-- is the state of a cell or organism having more than two paired (homologous) sets of chromosomes.

Nullisomic -----is a genetic condition involving the lack of both the normal chromosomal pairs for a species (2n-2).

So, the correct answer is 'Trisomy'