What is the condition called when a human male develops breast tissue similar to that of a female?

When the chromosome number of a given organism has one additional chromosome in one of the homologous pairs,the addition is known as

An abnormal male child is born to normal parents. This child shows a short neck,stubby hands,slanting eyes,a permanently open mouth with a projecting upper lip,and short stature. This abnormality can be attributed to:

Define aneuploidy. How is it different from polyploidy? Describe the individuals having the following chromosomal abnormalities:
$(a)$ Trisomy of $21^{st}$ chromosome
$(b)$ $XXY$
$(c)$ $XO$

An abnormal human baby with $XXX$ sex chromosomes was born due to

Match Column $I$ with Column $II$ and find the correct answer.

Column $I$	Column $II$
$(A)$ Aneuploidy	$(i)$ Increase in whole set of chromosomes
$(B)$ Monoploidy	$(ii)$ Loss or gain of a chromosome
$(C)$ Polyploidy	$(iii)$ Two sets of chromosomes
$(D)$ Diploidy	$(iv)$ $A$ single set of chromosomes