Thursday, October 1, 2009
It is a sex linked inheritance found in human beings. Persons suffering from colour blindness have difficulty in distinguishing red from green. It is rather common trait and more common in males. It is because Y chromosome is inert for this trait. Only one gene of this trait will render a colour blind man. While on the other hand a woman must have two genes for this trait to become colour blind.This trait of colour blindness can easily be detected by using special charts made up of a number of coloured dots so arranged that colour blind person sea different pattern than other persons do.
It is a type of chromosomal aberration in which a segment of chromosome is turned around 180º and is reinserted into the chromosome. An inversion does not involve a loss of genetic information but simply rearranges the linear gene sequence. An inversion involves two breaks along the length of the chromosome prior to the reinsertion of the inverted segments. The inverted segment may be short or quite long and may or may not include the Centromere. If the Centromere is not the part of the rearranged chromosome segment, the inversion is said to be