yoga wrote:
explanation: xlinked recessive disorder transmitted by mother & affect males so probably her brother has it ..transmitted from there mother
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| new_n_lost
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The correct answer is D.
The disease is Duchenne muscular dystrophy, an X-linked recessive muscular disease usually caused by a deletion involving the dystrophin gene. This defect produces accelerated muscle breakdown leading initially to proximal muscle weakness, then later to generalized weakness that typically begins before age 5. A feature of X-linked recessive diseases is that carrier mothers pass the disease to half their sons; affected fathers can have carrier daughters but not affected sons. Since the mother is presumably normal (because the disease is X-linked), she must be a carrier to have an affected son, and the grandmother must also be a carrier, therefore the mother's brother (maternal uncle) may also have the disease.
The father's (choice A) side of the family, including the father's brother (choice B), most likely does not carry the defective gene (since they themselves would be affected, and furthermore since the father cannot pass the gene on to a son). It would be extremely unlikely for a carrier female to marry an affected male (and the question does not mention any similar symptoms in the father).
The mother (choice C) and possibly the sister (choice E) are carriers of, but not affected by, the defective gene.
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| Ujk
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| yoga
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finally i got something right
thank God,,may i answer most of the q right
nnl dont u have q about becker?
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| new_n_lost
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I think i so no but maybe in the previous questions there a couple of them.
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FORUM RULES-- Those who believe in telekinesis, raise my hand. I get enough exercise just by pushing my luck --P4U World.." The pure and simple truth is rarely pure and never simple."
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