Question

Which of the following molecules would coded for by the longest piece of DNA, assuming that no post-transcriptional RNA processing or splicing has occurred?

(A): A protein with 25 amino acids
(B): A polysaccharide with 60 sugars
(C): A mRNA molecule with 20 codons
(D): An mRNA molecule with 45 nucleotides

Answer 1

The longest piece of DNA would code for a protein with 25 amino acids, requiring 75 nucleotides in total.

Step-by-step explanation:

The longest piece of DNA would code for a protein with 25 amino acids. Since each amino acid is defined by a three-nucleotide sequence called the triplet codon, we can calculate the number of nucleotides required by multiplying 25 by 3, giving us 75 nucleotides.

Answer 2

Answer: (A): A protein with 25 amino acids

Explanation: Nucleotides are macromolecules composed ofa 5-carbon sugar (ribose), a nitrogenous base, and a phosphate group and represent the building blocks of both our DNA and RNA.

Both codons and amino acids are built out of 3 nucleotides. Thus, 25 amino acids will yield 75 nucleotides whereas 20 codons only 60. In conclusion, the protein is coded from the longest piece of DNA.

B has nothing to do with DNA or RNA coding.