17.1

A particular triplet of bases in the template strand of DNA is AGT. The corresponding codon for the mRNA transcribed is

A) 3' UCA 5'.

A mutation results in a defective enzyme A. Which of the following would be a consequence of that mutation?

A) an accumulation of A and no production of B and C

Garrod hypothesized that "inborn errors of metabolism" such as alkaptonuria occur because

A) genes dictate the production of specific enzymes, and affected individuals have genetic defects that cause them to lack certain enzymes.

If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codon size in a genetic system with four different nucleotides?

B) 2

Using RNA as a template for protein synthesis instead of translating proteins directly from the DNA is advantageous for the cell because

B) RNA acts as an expendable copy of the genetic material.

A codon

B) may code for the same amino acid as another codon.

According to Beadle and Tatum's hypothesis, how many genes are necessary for this pathway?

C) 2

An extraterrestrial life form is discovered. It has a genetic code much like that of organisms on Earth except that there are five different DNA bases instead of four and the base sequences are translated as doublets instead of triplets. How many different amino acids could be accommodated by this genetic code?

C) 25

A peptide has the sequence NH2-phe-pro-lys-gly-phe-pro-COOH. Which of the following sequences in the coding strand of the DNA codes for this peptide?

C) 5' TTT-CCC-AAA-GGG-TTT-CCC

The enzyme polynucleotide phosphorylase randomly assembles nucleotides into a polynucleotide polymer. You add polynucleotide phosphorylase to a solution of adenosine triphosphate and guanosine triphosphate. The resulting artificial mRNA molecule would have ____ possible different codons if the code involved two-base sequences and ____ possible different codons if the code involved three-base sequences.

C) 8

The nitrogenous base adenine is found in all members of which group?

C) ATP, RNA, and DNA

If A, B, and C are all required for growth, a strain that is mutant for the gene encoding enzyme A would be able to grow on which of the following media?

C) minimal medium supplemented with nutrient "B" only

A particular eukaryotic protein is 300 amino acids long. Which of the following could be the maximum number of nucleotides in the DNA that codes for the amino acids in this protein?

D) 900

What amino acid sequence will be generated, based on the following mRNA codon sequence? 5'AUG-UCU-UCG-UUA-UCC-UUG

D) met-ser-ser-leu-ser-leu

If A, B, and C are all required for growth, a strain mutant for the gene encoding enzyme B would be capable of growing on which of the following media?

D) minimal medium supplemented with "C" only

Which of the following represents a similarity between RNA and DNA?

D) nucleotides consisting of a phosphate, sugar, and nitrogenous base

Suppose the following DNA sequence was mutated from 3' AGAGAGAGAGAGAGAGAG 5' to 3' AGAAGAGAGATCGAGAGA 5'. What amino acid sequence will be generated based on this mutated DNA?

D) ser-ser-leu

A possible sequence of nucleotides in the template strand of DNA that would code for the polypeptide sequence phe-leu-ile-val would be

E) 3' AAA-GAA-TAA-CAA 5'.

We now know that the one gene-one enzyme hypothesis is not entirely accurate because

E) A, B, and C

What is the sequence of a peptide based on the mRNA sequence 5' UUUUCUUAUUGUCUU 3' ?

E) phe-ser-tyr-cys-leu