Question

What is the type of genetic inheritance of color blindness? Is color blindness more frequent in men or in women? What is the physiological explanation for color blindness?

Answer 1

Type of Genetic Inheritance of Color Blindness

1. A colour blind man and a non-colour blind woman :- no colour blindness in all Sons but all Daughters are colour blind gene carries

2. A non colour blind man and a colour blind carrier woman :- 50% chance of Sons being Color blind and 50% chance of Daughters being colour blind gene carries

3. A colour blind man and a colour blind carrier woman :- 50% chance of Sons being Color blind and 50% chance of Daughters being either colour blind gene carries or a colour blind

4. A non colour blind man and a colour blind woman :- all Sons will be colour blind and all Daughters will be colour blind gene carries

All of these solve by pedigree

Color Blindness more frequent in Men

genetic red–green color blindness affects males much more often than females, because the genes for the red and green color receptors are located on the X chromosome, of which males have only one and females have two.

The physiology of colour Blindness

as is the way in which the human eye can detect various combinations of red, green and blue.

Red-green colour blindness, with X-linked inheritance, is the most common, but other types are also considered.

Methods of testing relating to the age of the child are reviewed.

The use of colours in teaching is widespread, but there is controversy over the difficulties this may cause a colour blind child.

A review of the literature does not reveal much information on this, and any problems that do arise are likely to be individual to the child, and to depend on such factors as overall intelligence, the attitude of the teacher, and the personality of the child.

There is not doubt that it is essential to recognise colour vision defects when it comes to choosing a career, and that tests must be done during secondary schooling, but in order to avoid some affected children being disadvantaged there is enough evidence to support testing at school entry.