This disease falls under the same category as colourblindness in man

The correct option is Haemophilia.

To understand why this is the correct choice, let us break down the genetic classification of these diseases:

1. Genetic Category of Colourblindness:
Colourblindness in humans is a classic example of an X-linked recessive disorder. This means the gene responsible for the condition is located on the X chromosome (one of the two sex chromosomes), and the trait is recessive. Therefore, males (who have only one X chromosome, XY) express the disease if they inherit a single mutated X chromosome, while females (who have two X chromosomes, XX) typically only express it if they inherit two copies of the mutated gene.

2. Comparing the Options:
Let us evaluate each of the given options to find which one shares this exact genetic category:

* Haemophilia: Like colourblindness, haemophilia is also an X-linked recessive disorder. It is caused by a deficiency in blood clotting factors (such as Factor VIII in Haemophilia A or Factor IX in Haemophilia B), leading to prolonged bleeding. Because the defective gene resides on the X chromosome, it follows the exact same pattern of inheritance as colourblindness.
* Presbyopia: This is an age-related vision condition caused by the gradual loss of flexibility in the eye's natural lens, making it difficult to focus on close objects. It is not an inherited X-linked genetic disorder.
* Diabetes insipidus: This condition is characterized by polydipsia (excessive thirst) and polyuria (excessive urination), caused by a deficiency of the hormone vasopressin (ADH) or a lack of response to it. While some rare forms can be genetic, it does not classically fall under the same primary inheritance category as colourblindness.
* Night blindness: This is most commonly caused by nutritional deficiency (specifically Vitamin A deficiency) or other ocular conditions, and is not categorized as an X-linked recessive genetic disorder like colourblindness.

Therefore, Haemophilia is the disease that falls under the same genetic category (X-linked recessive inheritance) as colourblindness in humans.