A true reversion occurs when the wild-type DNA sequence is restored to encode its original message by a second mutation at the same site or within the same cod on. Which of the following isoleucine codon(s) could be mutated once to form a methionine codon, and then mutated at a second site to restore an isoleucine codon? Select all that apply. (Note that two different positions in the codon must be mutated.)

AUC
AUU
AUA
none of these codons

Blood has traveled from the heart to the toes. which describes the next step of the circulation process?

Punnett squares are used to show possible combinations of alleles or to predict the probability of a trait occurring in offspring. an incomplete dominance cross is performed between a bird that is homozygous for red feathers and a bird that is homozygous for blue feathers. purple offspring result. then, two of the purple offspring are crossed. according to the punnett square for this cross, how many of the offspring from the second cross will have a feather color that results from incomplete dominance? 1 in 4 2 in 4 3 in 4 4 in 4

What is the one part of the nucleotide  that differs among the other different nucle  tides?