Question

1) A polypeptide produced in a cell is 1,533 amino acids in length.
The number of codons found on the mRNA used to produce the polypeptide is

Select one:

a. 4,599

b. 511

c. 4,602

d. 1,533

e. 1,534

2) A gene generates an mRNA that codes for a polypeptide 20 amino acids in length. The number of nucleotides in the coding region of the mRNA is

Select one:

a. 60

b. 63

c. 57

d. 19

e. 20

Answer 1

1.Answer d.1533

Length of polypeptide =1533 amino acids.

A codon comprises of three nucleotides that corresponds with a specific amino acid .One codon encodes one amino acid .Here 1533 codons are required for producing 1533 amino acids of the polypeptide.

Options a,b,c and e are wrong values

2 Answer a.60

Three nucleotides encode one amino acid.

Number of amino acids =20

The number of nucleotides in the coding region of the mRNA is 20 *3 =60 nucleotides

Options b,c d and e are wrong values.