Question 1

Which of the following statements best describes the degeneracy of the genetic code?

Accepted Answer

Some amino acids are encoded by multiple codons.

Question 2

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

Accepted Answer

Silent mutation

Question 3

Which of the following codons serves as the initiation codon for translation in most organisms?

Accepted Answer

AUG

Question 4

If the mRNA sequence is 5'-AUGGCCUAA-3', what is the corresponding amino acid sequence?

Accepted Answer

Met-Ala-Stop

Question 5

Which property of the genetic code allows for the phenomenon known as 'wobble'?

Accepted Answer

The third base of the codon is less important for tRNA recognition.

Question 6

What is the role of aminoacyl-tRNA synthetases in translation?

Accepted Answer

They attach amino acids to their corresponding tRNAs.

Question 7

Which of the following best explains why the genetic code is considered universal?

Accepted Answer

The same codons specify the same amino acids in almost all organisms.

Question 8

A tRNA has the anticodon 5'-GAA-3'. Which mRNA codon will it recognize, and which amino acid will be incorporated?

Accepted Answer

5'-UUC-3', Phenylalanine

Question 9

Which of the following is a consequence of a frameshift mutation in a coding sequence?

Accepted Answer

All amino acids downstream of the mutation are likely to be altered.

Question 10

Which of the following statements about tRNA structure is correct?

Accepted Answer

tRNA has a cloverleaf secondary structure and an L-shaped tertiary structure.

Question 11

Which of the following best describes the function of the editing site in threonyl-tRNA synthetase?

Accepted Answer

It removes incorrectly attached serine from tRNA.

Question 12

Which of the following codons is a stop codon?

Accepted Answer

UAA

Question 13

During translation, which direction is the mRNA read by the ribosome?

Accepted Answer

5' to 3'

Question 14

Which of the following is true regarding the wobble hypothesis?

Accepted Answer

The third base of the codon can pair with multiple bases in the anticodon.

Question 15

Which of the following steps in protein synthesis involves the hydrolysis of pyrophosphate ($$PP_i$$)?

Accepted Answer

Amino acid activation by aminoacyl-tRNA synthetase

Question 16

A mutation changes the first base of a codon from G to A. Which of the following is most likely to occur?

Accepted Answer

A conservative substitution

Question 17

Which of the following best describes the role of the CCA sequence at the 3' end of tRNA?

Accepted Answer

It is the attachment site for the amino acid.

Question 18

Which of the following is a direct result of the universality of the genetic code?

Accepted Answer

Human genes can be expressed in bacteria to produce human proteins.

Question 19

Which of the following best explains why aminoacyl-tRNA synthetases are considered the 'true translators' of the genetic code?

Accepted Answer

They assign specific amino acids to their corresponding tRNAs.

Question 20

A tRNA with the anticodon 5'-ICG-3' can recognize which of the following mRNA codons according to the wobble hypothesis?

Accepted Answer

5'-CGA-3', 5'-CGU-3', and 5'-CGC-3'

The Genetic Code and Translation: Structure, Function, and Fidelity

Guida di studio - Domande di pratica