Question 1

Which of the following best describes the concept of degeneracy in the genetic code?

Accepted Answer

Multiple codons can code for the same amino acid, often differing at the third base.

Question 2

A mutation changes the codon GAA to GAG in an mRNA sequence. Both codons code for glutamic acid. What type of mutation is this?

Accepted Answer

Silent mutation

Question 3

Which of the following statements about the wobble hypothesis is correct?

Accepted Answer

Wobble allows a single tRNA to recognize multiple codons for the same amino acid.

Question 4

During translation in prokaryotes, which of the following is the first amino acid incorporated into the polypeptide chain?

Accepted Answer

N-formyl methionine (f-met)

Question 5

Which ribosomal subunit combination is found in eukaryotes?

Accepted Answer

60S and 40S

Question 6

A patient is diagnosed with sickle-cell anemia. Which change in the hemoglobin β-chain is responsible for this disease?

Accepted Answer

Glutamic acid is replaced by valine at position 6.

Question 7

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids in a polypeptide chain.

Question 8

Which of the following is a post-translational modification that can activate a protein?

Accepted Answer

Hydroxylation of proline residues in procollagen.

Question 9

Which of the following is a function of immunoglobulins?

Accepted Answer

Functioning in the immune system of vertebrates

Question 10

A mutation in the gene encoding a protein causes it to misfold and aggregate in the brain, leading to neurodegenerative disease. Which of the following diseases is most likely associated with this mechanism?

Accepted Answer

Alzheimer disease

Question 11

Which of the following events occurs during the elongation phase of translation?

Accepted Answer

Peptide bond formation between amino acids in the P and A sites

Question 12

Which of the following statements about gene expression control is correct?

Accepted Answer

Gene expression can be regulated at multiple levels, including chromosomal, transcriptional, post-transcriptional, and post-translational.

Question 13

Which of the following best explains why degeneracy in the genetic code increases phenotypic stability?

Accepted Answer

It allows for the same amino acid to be incorporated even if a mutation occurs at the third base of a codon.

Question 14

A researcher observes that a certain tRNA can recognize both the codons UCU and UCC for serine. Which molecular mechanism allows this?

Accepted Answer

Wobble base pairing at the third codon position

Question 15

Which of the following is true regarding translation in prokaryotes?

Accepted Answer

Translation can begin before transcription is complete.

Question 16

Which of the following is a real-life example of gene amplification?

Accepted Answer

The extrachromosomal replication of ribosomal genes in Xenopus oocytes

Question 17

A mutation in the anticodon loop of a tRNA prevents it from recognizing its corresponding codon. What is the most likely consequence?

Accepted Answer

The corresponding amino acid will not be incorporated into the growing polypeptide.

Question 18

Which of the following best describes the quaternary structure of a protein?

Accepted Answer

The association of multiple polypeptide chains into a functional protein complex.

Question 19

Which of the following is a property of enzymes as proteins?

Accepted Answer

They catalyze chemical reactions and increase the rate at which equilibrium is reached.

Question 20

A patient is found to have a mutation that causes the loss of a chromosome during development. Which organism is known to naturally exhibit this phenomenon?

Accepted Answer

Ascaris

Genetic Code, Translation, and Protein Structure: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard