MSUD is a rare inborn error in metabolism ..affected individuals cannot completely degrade AA Leucine,isoleucine, valine due to lack of activity of certain degradative enzymes..accumulated degradative enzymes, keto acids are excreted in urine and sweat

 

autosomal recessive trait.

 

This is practice work

Question 1

MSUD allele affects phenotype by altering

a) The enzyme responsible for degrading valien isolecuine and lecuin**i thought this was the answer..does not make sense why is this incorrect?

b) but the answer is none of the above.

 

Question 2

which is true

a)nucleotide sequence for MSUD allele is different then the nucleotide sequence for normal allele...yes this is correct

b)MUSUD allele of one individual must be identical to the MSUD allele of another individual** I thought they were both correct

but the answer is just a.

 

why would b) be incorrect? example to individuals have blue eye doesn't this mean there alleles are identical same nucleotide sequence?

There are a couple of misunderstandings here so I can offer the following to help you with ideas of genotype, phenotype and alleles.Link

and a nice online textbook:

Link