Question 1

Which statement best describes the central dogma of molecular biology as illustrated in Chapter 17?

Accepted Answer

Genetic information flows from DNA to RNA to protein.

Question 2

What is the primary function of transcription in gene expression?

Accepted Answer

To turn the DNA base sequence for a polypeptide into an mRNA copy.

Question 3

Which of the following statements about gene coding is supported by the study materials?

Accepted Answer

One gene can code for more than one polypeptide.

Question 4

In eukaryotic cells, what must happen to mRNA before it can be translated?

Accepted Answer

It must undergo RNA processing before leaving the nucleus.

Question 5

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

Accepted Answer

In eukaryotes, transcription and translation are separated by the nuclear envelope.

Question 6

If a mutation changes the codon UUU to UUC, what is the likely effect on the protein produced?

Accepted Answer

There will be no change in the amino acid sequence because both codons code for phenylalanine.

Question 7

Which codon serves as the start signal for translation in most organisms?

Accepted Answer

AUG

Question 8

Given the DNA template strand 3'-TACGGTACG-5', what is the corresponding mRNA sequence produced during transcription?

Accepted Answer

$$5'-AUGCCAUGC-3'$$

Question 9

Which process directly uses the ribosome as shown in Figure 17.0?

Accepted Answer

Translation

Question 10

A mutation changes the codon GAA to GAG. Using the genetic code, what is the effect on the protein?

Accepted Answer

There is no change; both codons code for glutamic acid.

Question 11

Which of the following best explains why there are more proteins than genes in humans?

Accepted Answer

Alternative splicing and post-translational modifications allow one gene to produce multiple proteins.

Question 12

What is the role of the codon dictionary shown in Figure 17.6?

Accepted Answer

It matches mRNA codons to their corresponding amino acids during translation.

Question 13

If a mutation changes a codon from UAU (tyrosine) to UAA, what is the consequence for the protein?

Accepted Answer

Translation will stop prematurely due to a stop codon.

Question 14

Which of the following best describes the process of translation?

Accepted Answer

The assembly of a polypeptide based on the sequence of codons in mRNA.

Question 15

A patient has a mutation in a gene that changes the codon for glycine (GGU) to GGA. What is the effect on the protein?

Accepted Answer

There will be no change; both codons code for glycine.

Question 16

Which of the following is true about the genetic code?

Accepted Answer

Some amino acids are coded by more than one codon.

Question 17

What would be the result if a mutation changed the start codon AUG to AAG in an mRNA sequence?

Accepted Answer

Translation would likely fail to initiate, preventing protein synthesis.

Question 18

Which process is responsible for converting the information in mRNA into a sequence of amino acids?

Accepted Answer

Translation

Question 19

If a DNA sequence reads 3'-ATGCGT-5', what is the corresponding mRNA sequence after transcription?

Accepted Answer

$$5'-UACGCA-3'$$

Question 20

Why might a mutation in the third base of a codon have less impact on the protein than a mutation in the first or second base?

Accepted Answer

Many amino acids are coded by multiple codons that differ only in the third base.

Gene Expression: From DNA to Protein (Chapter 17 Study Notes)

Study Guide - Practice Questions