In: Biology
Phenylketonuria (PKU) is an autosomal recessive metabolic disorder that can result in mental retardation if left untreated. Two normal parents produce a child with PKU.
If the recessive PKU allele is ‘n’ and the dominant normal allele is ‘N’, what are the genotypes of both parents?
A. Mother is NN and Father is nn
B. Mother is Nn and Father is nn
C. Mother is nn and Father is Nn
D. Mother and Father are both Nn
E. Mother and Father are both nn
Phenylketonuria (PKU) is an autosomal recessive metabolic disorder that can result in mental retardation if left untreated. Two heterozygous individuals have a child.
What is the probability that a sperm from the father will contain the normal allele?
A. 1/2
B. 1/4
C. 1/8
D. 1/16
E. 0
Phenylketonuria (PKU) is an autosomal recessive metabolic disorder that can result in mental retardation if left untreated. Two heterozygous individuals produce a child with PKU.
What is the probability that their next child will be a son who has PKU ?
A. 1/2
B. 1/4
C. 1/6
D. 1/8
E. 1/16
phenylketonuria is autosomal recessive disease which is caused by homozygous recessive nn allele . Parents are normal it means both alleles may be homozygous dominant (NN) or heterozygous (Nn). their progeny is affected when both parents contributing n type of allele in their progeny and form (nn) gentype which are affected by the phenyketonoueria. If parents having heterozygous allele of phenylketonuria then there is possibility to produces 50% of the progeny affected with phenylketonouria. so the both parents having (Nn) type of genotype so they are normal and they produce affected progeny. D. mother and father are both Nn option is correct.
heterozygous male donating sperm 1/2 normal allele to the progeny.
both parents heterozygous for phenylketonuria allele so both are normal but the produce the progeny affected with phenylketonuria it means both alleles is homozygous recessive. Provability of appearing the affected progeny from the normal heterozygous parents is 1/4.becaus 1/2 affected allele comes from father and 1/2 from mother so the total provability is 1/4