AP BIOLOGY

Detailed explanation-1: -So, for a male to be colour blind the colour blindness ‘gene’ only has to appear on his X chromosome. For a female to be colour blind she must have colour blindness ‘genes’ present on both of her X chromosomes. If a woman has only one colour blind ‘gene’ she is known as a ‘carrier’ but she won’t be colour blind.

Detailed explanation-2: -Since it’s passed down on the X chromosome, red-green color blindness is more common in men. This is because: Males have only 1 X chromosome, from their mother. If that X chromosome has the gene for red-green color blindness (instead of a normal X chromosome), they will have red-green color blindness.

Detailed explanation-3: -As females possess two X-chromosomes, they can “carry” a red-green colour vision deficiency – that is, one of their L/M gene arrays encodes a colour vision defect. In fact, some 15% of women are heterozygous carriers of colour vision deficiency.

Detailed explanation-4: -Color blindness is more common in men. Women are more likely to carry the defective chromosome responsible for passing on color blindness, but men are more likely to inherit the condition.

Detailed explanation-5: -Color-blindness is carried on the X chromosome. Men, being XY, will either be color-blind or not. Men cannot be carriers. Women, being XX, can be color-blind (if both X chromosomes carry the color-blindness gene), carriers (if only one of their X chromosomes carries the gene), or completely free of the gene.