Zoology - Principles of Inheritance and Variation Question with Solution | TestHub

The chromosomal disorder occurs when there is an addition or deletion of the chromosome in the individual. In the case of trisomy of the 21st chromosome causes Down's syndrome. Turner's syndrome is a type of chromosomal disorder occurring due to loss of one X chromosome resulting in the genotype as 44+X or 44+XO. Such females are characterized by stunted height and webbed-neck. They are sterile as ovaries are rudimentary and lack secondary sexual characteristics.

Haemophilia is an X-linked recessive blood disorder. In it, the individual has delayed clotting time for blood which can be fatal. X-lined disorders are inherent disorders due to mutation in the X-chromosome which causes the phenotype to be always expressed in male and in female only in homozygous condition.

Cystic fibrosis is a hereditary genetic autosomal recessive disorder of the respiratory system. It is caused due to mutation in the CFTR gene. This condition occurs in an individual when both the alleles for CFTR are affected.