One of the following is holandric inheritance A. Haemophilia B. Epidermolysis C. Webbed toes D. Turner’s syndrome
Hint: Holandric inheritance is also known as Y-linked inheritance. The condition caused by it comes under a group that also includes hypertrichosis of the ears and porcupine man. The condition occurs in the lower limbs of the body.
Complete answer: Webbed toes are a result of holandric inheritance. ‘Webbed toes’ is a condition that is characterized by a web-like structure and appearance between the second and third toes. Holandric inheritance is also known as Y – linked inheritance. It is a form of inheritance for the genes that are located on the Y – chromosome. As compared to the X – chromosome, the Y – chromosome is relatively smaller and has fewer genes. The genes on the Y chromosome mainly code for sperm development, hormonal output, and other characteristic male traits. However, it does contain genes that are for purposes other than sex determination. Other Y – linked conditions are hypertrichosis of ears and porcupine man. In hypertrichosis of the ears, there is an abnormal amount of hair growth on the outer ears. In porcupine ma, the skin thickens and becomes dark, scaly, and rough. Y – linked conditions can be passed on from the father to a son only.
The correct answer is option ( C ). That is webbed toes.
Additional information: Haemophilia: the pattern of inheritance for Haemophilia is X-linked recessive. This means that this condition can occur only in a female when both the X – chromosomes have the gene for haemophilia. Epidermolysis: the pattern of inheritance for this condition is autosomal dominant. This means that only one copy of the gene is required to cause this disease. Turner’s syndrome: this condition is not inherited. It occurs when one out of the two X – chromosomes in a female is either missing or incomplete.
Note: Another term that can be used for webbed toes is ‘Syndactyly’. In severe cases, it may involve other parts of the body also, such as – bones, blood vessels, muscles, and nerves. The only way to fix webbed toes is through surgery.