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

When a specific disease/condition/defect is inherited through the autosomal chromosomes, such disorders are called autosomal disorders. And they are called as recessive autosomal disorders as these are expressed only in homozygous condition.

For it to occur in an individual, both the parents must have the gene either in heterozygous or homozygous form.

Cystic fibrosis is a hereditary genetic 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.

Albinism is an inherent condition where very low amount of melanin is produced in skin, hair and or eyes. It is also a autosomal recessive disorder which require presence of homozygous condition in the defective gene for expression. In humans, mutation of TRP-1 gene results in the condition.

Alkaptonuria is a rare genetic condition where body is not able to break down homogentisic acid and its accumulation causes formation of black colour urine. It is due to mutation in HGD gene and is a recessive autosomal disorder.