$$\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}$$

Question 1

Which of the following best describes the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} ightarrow 	ext{RNA} ightarrow 	ext{Protein}$$

Question 2

During DNA replication, which enzyme is responsible for unwinding the DNA double helix?

Accepted Answer

Helicase

Question 3

What is the function of the RNA primer during DNA replication?

Accepted Answer

It provides a starting point for DNA polymerase to add nucleotides.

Question 4

Which of the following statements about the lagging strand during DNA replication is correct?

Accepted Answer

It is synthesized discontinuously in short fragments called Okazaki fragments.

Question 5

In the process of transcription in prokaryotes, what signals the end of transcription?

Accepted Answer

A terminator sequence on the DNA

Question 6

Which of the following is true regarding the genetic code?

Accepted Answer

It is degenerate, meaning multiple codons can code for the same amino acid.

Question 7

A mutation changes a codon from UAU (tyrosine) to UAA. What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 8

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

Accepted Answer

It brings the correct amino acid to the ribosome by matching its anticodon to the mRNA codon.

Question 9

Which process is illustrated by the removal of introns and joining of exons in eukaryotic cells?

Accepted Answer

RNA splicing

Question 10

Which of the following is a characteristic of plasmids?

Accepted Answer

They are self-replicating, circular DNA molecules found primarily in bacteria.

Question 11

Which mechanism of horizontal gene transfer involves the uptake of naked DNA from the environment?

Accepted Answer

Transformation

Question 12

What is the function of DNA ligase during DNA replication?

Accepted Answer

It joins Okazaki fragments on the lagging strand.

Question 13

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

Accepted Answer

More than one codon can specify the same amino acid.

Question 14

Which of the following is an example of a repressible operon?

Accepted Answer

trp operon

Question 15

A chemical mutagen that is structurally similar to a normal DNA base and can be incorporated into DNA, causing base-pairing errors, is called:

Accepted Answer

A nucleoside analog

Question 16

Which of the following best describes generalized transduction?

Accepted Answer

Random bacterial DNA is packaged inside a phage and transferred to a recipient cell.

Question 17

Which of the following is a consequence of a frameshift mutation?

Accepted Answer

It alters the reading frame, potentially changing every amino acid downstream from the mutation.

Question 18

Which enzyme is responsible for proofreading newly synthesized DNA and correcting errors?

Accepted Answer

DNA polymerase

Question 19

In the lac operon, what happens when lactose is present?

Accepted Answer

Allolactose binds to the repressor, preventing it from binding to the operator, allowing transcription.

Question 20

Which of the following best describes the difference between vertical and horizontal gene transfer?

Accepted Answer

Vertical gene transfer is from parent to offspring, while horizontal gene transfer is between cells of the same generation.

Chapter 8

Guida di studio - Domande di pratica