A disease caused by an autosomal primary non disjunction is
Klinefelter’s syndrome
Turner’s syndrome
sickle cell anaemia
Down’s syndrome.
The recessive genes located on $X$-chromosome in humans are always
It is character of disorder which described by Langdon Down.
Who reported that Down’s syndrome is due to extra $21^{st}$ chromosome
Chromosome complement with $2n-1$ is called as
Describe chromosomal disorder and describe its examples.