GENETICS AND EVOLUTION
GENETIC BASIS OF INHERITANCE
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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X-linked
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Sex-linked
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X/Y Disorders
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X Disorders
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Detailed explanation-1: -Sex-linked diseases are passed down through families through one of the X or Y chromosomes. X and Y are sex chromosomes. Dominant inheritance occurs when an abnormal gene from one parent causes disease, even though the matching gene from the other parent is normal.
Detailed explanation-2: -When a gene is present on the X chromosome, but not on the Y chromosome, it is said to be X-linked. X-linked genes have different inheritance patterns than genes on non-sex chromosomes (autosomes). That’s because these genes are present in different copy numbers in males and females.
Detailed explanation-3: -A characteristic of X-linked inheritance is that fathers cannot pass X-linked traits to their sons (no male-to-male transmission). A condition is considered Y-linked if the altered gene that causes the disorder is located on the Y chromosome, one of the two sex chromosomes in each of a male’s cells.
Detailed explanation-4: -Hypertrichosis of the ears, webbed toes, and porcupine man are examples of Y-linked inheritance in humans. Hypertrichosis of the ears (or hairy ears) is a condition wherein there is a conspicuous growth of hair on the outside rim of the ear.