Question

0 no poly U 240 0 0. 0 999 0 10 20 30 40 50 60 70 80 time (min) How do the data in Figure 2.21A support linking the codon UUU to the amino acid phenylalanine? These data support that you need a codon of threenucleotides to code for 1 amino a When ribosomes, poly-u, tRNA, and amino acids were mixed, short sequences of phenylalanine amino acids were synthesized. When ribosomes, mRNA, TRNA, and phenylalanine were mixed, short sequences of poly-U were synthesized. When ribosomes, tRNA, and amino acids were mixed together in the absence of mRNA, no proteins are produced,

Answer 1

Option B is correct

When ribosome, poly U , tRNA and amino acid were mixed , short sequence of phenylalanine amino acids were synthesized.

As we can see lines in pink and green colour there is no phenylalanine polymerization present because there is no poly U sequence provided . This means poly U sequence must be present in order to carry out phenylalanine polymerization.

According to this information option c is wrong it says sequence of poly U is synthesized which is actually reverse. Poly U sequence lead to addition of phenylalanine. As UUU genetic codon codes for phenylalanine.

Option D us also wrong , as mRNA is required to carry out peptide chain synthesis. It carries the information required for addition of amino acids.

Rest of the above lines shows phenylalanine polymerization in presence of poly U sequence up to 7 number of phenylalanine amino acids which is actually short peptide.

Black Line is at 37 is optimum temperature, shows rapid synthesis of short peptide

When temperature increases slowly ( yellow) polymerization increases slowly, reached up to 7 no of phenylalanine sequence.  

So option B is most suitable answer