Question 1

Which of the following best explains why the genetic code is described as 'degenerate'?

Accepted Answer

A given amino acid can be specified by more than one codon.

Question 2

A mutation changes the DNA sequence from 5'-GAA-3' to 5'-GAG-3'. Both codons code for glutamic acid. What type of mutation is this?

Accepted Answer

Silent mutation

Question 3

Which of the following is the correct tRNA anticodon (written 5' to 3') that would pair with the mRNA codon 5'-AUG-3'?

Accepted Answer

5'-UAC-3'

Question 4

A patient with sickle-cell anemia has a single nucleotide change in the HBB gene that results in a different amino acid being incorporated into the hemoglobin protein. This is an example of which type of mutation?

Accepted Answer

Missense mutation

Question 5

Which of the following statements about translation in prokaryotes is correct?

Accepted Answer

Translation begins at the Shine-Dalgarno sequence.

Question 6

If a single nucleotide is inserted into the coding region of a gene, what is the most likely consequence?

Accepted Answer

A frameshift mutation

Question 7

Which of the following codons is a stop codon in the standard genetic code?

Accepted Answer

UAA

Question 8

A mutation in the aminoacyl tRNA synthetase for valine causes it to attach glycine to tRNA^Val instead of valine. What will happen during translation?

Accepted Answer

Glycine will be incorporated at all valine codons.

Question 9

Which of the following best describes the wobble hypothesis?

Accepted Answer

The third base of the codon is less spatially constrained and can pair with multiple bases.

Question 10

Which of the following is a key difference between translation in prokaryotes and eukaryotes?

Accepted Answer

Eukaryotes use a Kozak sequence to enhance initiation efficiency.

Question 11

Given the mRNA sequence 5'-AUGGCAAAAAAGUGA-3', what is the resulting amino acid sequence?

Accepted Answer

Met-Ala-Lys-Lys

Question 12

Which of the following is NOT a feature of the genetic code?

Accepted Answer

It is ambiguous.

Question 13

Which of the following is true regarding posttranslational modifications?

Accepted Answer

They can alter the functional capability of the final protein product.

Question 14

Which of the following best describes the role of tRNA during translation?

Accepted Answer

It carries amino acids to the ribosome and matches them to the mRNA codon.

Question 15

Which of the following is the correct sequence of events during translation elongation in bacteria?

Accepted Answer

tRNA entry into A site, peptide bond formation, translocation

Question 16

Which of the following is a direct result of a nonsense mutation in a gene?

Accepted Answer

A stop codon is introduced, leading to a truncated protein.

Question 17

Which of the following is true about the universality of the genetic code?

Accepted Answer

Mitochondria in some organisms use variations of the standard code.

Question 18

Which of the following is the correct order of protein structural levels from simplest to most complex?

Accepted Answer

Primary, secondary, tertiary, quaternary

Question 19

Which of the following is a function of the large ribosomal subunit during translation?

Accepted Answer

Catalyzing peptide bond formation

Question 20

A prokaryotic cell is exposed to the antibiotic streptolydigin, which allows RNA polymerase to bind to promoters but prevents RNA synthesis. What is the most likely mechanism of action?

Accepted Answer

Blocks the catalytic activity of the polymerase

Chap 13+14

Guida di studio - Domande di pratica

Study guide - Flashcard