Turner's syndrome in humans is caused by

Identify the disease on the basis of the following characters:
$(1)$ Short stature with a small round head.
$(2)$ Furrowed tongue and partially open mouth.
$(3)$ Palm is broad with a characteristic palm crease.

Down syndrome is caused by an extra copy of chromosome $21$. If an affected mother and a normal father produce offspring,what percentage of the offspring will be affected by this disorder (in $\%$)?

Which of the following does not represent trisomy?

Explain chromosomal disorders involving autosomes and sex chromosomes with examples.

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