$$\text{A} \rightarrow \text{U}$$

Question 1

Which of the following correctly describes the backbone structure of a nucleic acid molecule?

Accepted Answer

It consists of alternating sugar and phosphate units.

Question 2

A DNA sample contains 35% guanine. What percentage of the bases in this DNA sample are adenine?

Accepted Answer

15%

Question 3

Which of the following statements about the double helix structure of DNA is correct?

Accepted Answer

Base pairing between nucleotides always occurs between purine and pyrimidine bases.

Question 4

During DNA replication, which enzyme is responsible for joining Okazaki fragments together?

Accepted Answer

DNA ligase

Question 5

Which of the following is a correct base pairing sequence between a codon and anticodon?

Accepted Answer

$$	ext{A} ightarrow 	ext{U}$$

Question 6

Which of the following types of RNA has a 'cloverleaf' shape with three hairpin loops?

Accepted Answer

tRNA

Question 7

Which of the following statements concerning ribosomes is correct?

Accepted Answer

Ribosomes are composed of protein and rRNA.

Question 8

Which of the following is NOT a function of mRNA?

Accepted Answer

Forming the structural core of ribosomes.

Question 9

Which of the following statements about the composition of DNA is consistent with the double helix nature?

Accepted Answer

25% A and 25% T

Question 10

Which of the following statements about the genetic code is correct?

Accepted Answer

The total number of codons is 64.

Question 11

Which of the following is a correct characterization of the difference between DNA and RNA nucleotides?

Accepted Answer

DNA contains deoxyribose, RNA contains ribose.

Question 12

Which of the following statements about Okazaki fragments is correct?

Accepted Answer

They are short DNA fragments synthesized on the lagging strand.

Question 13

Which of the following is a correct sequence of events during the transcription phase of protein synthesis?

Accepted Answer

DNA unwinds, mRNA is synthesized, mRNA leaves the nucleus.

Question 14

Which of the following statements about the role of E. coli plasmids in recombinant DNA work is correct?

Accepted Answer

They are used as vectors to transfer DNA into bacterial cells.

Question 15

Which of the following statements about the process of translation is correct?

Accepted Answer

tRNA brings amino acids to the ribosome.

Question 16

Which of the following is a correct description of a gene?

Accepted Answer

A gene is a sequence of a DNA molecule that contains instructions for the synthesis of one or more proteins.

Question 17

Which of the following statements about the pairing of bases in nucleic acids is correct?

Accepted Answer

$$	ext{A}$$ pairs with $$	ext{T}$$ and $$	ext{G}$$ pairs with $$	ext{C} in $$DNA.

Question 18

Which of the following statements about the function of tRNA is correct?

Accepted Answer

tRNA carries amino acids to the ribosome during protein synthesis.

Question 19

Which of the following statements about the process of PCR (polymerase chain reaction) is correct?

Accepted Answer

PCR is used to amplify specific DNA sequences.

Question 20

Which of the following statements about the difference between DNA and RNA is correct?

Accepted Answer

DNA contains deoxyribose, RNA contains ribose.

Chapter 22

Guida di studio - Domande di pratica