THE MOLECULAR BASIS OF INHERITANCE
THE HUMAN GENOME
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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a Y chromosome.
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an inactivated allele.
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two recessive alleles.
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two dominant alleles.
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Detailed explanation-1: -When a trait is recessive, an individual must have two copies of a recessive allele to express the trait.
Detailed explanation-2: -Individuals inherit two versions of each gene, known as alleles, from each parent. In the case of a recessive trait, the alleles of the trait-causing gene are the same, and both (recessive) alleles must be present to express the trait. A recessive allele does not produce a trait at all when only one copy is present.
Detailed explanation-3: -Recessive alleles only show the traits if the person has 2 copies of the same alleles. This is considered being homozygous, having the same 2 copies of alleles. If a person has 2 copies of the blue eye allele (both recessive) then the person would have blue eyes.
Detailed explanation-4: -If you are born to parents who both carry the same autosomal recessive gene, you have a 25% (1 in 4) chance of inheriting the abnormal gene from both parents and developing the disease. You have a 50% (1 in 2) chance of inheriting one abnormal gene. This would make you a carrier.