PATHOLOGY MCQ
GENETICS AND DISEASE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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The allele for color blindness is recessive and located on the X chromosome
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Color blind males have two copies of the allele for color blindness
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The allele for color blindness is located on the Y chromosome
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Fathers pass the allele for color blindness to their sons only
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Detailed explanation-1: -Males have 1 X chromosome and 1 Y chromosome, and females have 2 X chromosomes. The genes that can give you red-green color blindness are passed down on the X chromosome. Since it’s passed down on the X chromosome, red-green color blindness is more common in men.
Detailed explanation-2: -This is because the genes for the color vision cone light-sensitive proteins are on the X chromosome, of which males have one and females have two.
Detailed explanation-3: -Colour (color) blindness (colour vision deficiency, or CVD) affects approximately 1 in 12 men (8%) and 1 in 200 women.
Detailed explanation-4: -Colour blindness is a X linked recessive disorder in which the eye fails to distinguish between red and green colours. If a colour blind woman with genotype (XCXC) marries a normal visioned man (XY).