$$5'\text{ AUG CCU AGG CUU }3'$$

mRNA: $$5'\text{ AUG GCU UGA }3'$$, Amino acids: Met-Ala-Stop

Question 1

Which enzyme is responsible for synthesizing mRNA from a DNA template during transcription?

Accepted Answer

RNA polymerase

Question 2

Given the following DNA template strand: $$3'	ext{ TAC GGA TCC GAA }5'$$, what is the corresponding mRNA sequence?

Accepted Answer

$$5'	ext{ AUG CCU AGG CUU }3'$$

Question 3

Which of the following best describes why the genetic code is considered redundant?

Accepted Answer

Multiple codons can code for the same amino acid.

Question 4

A mutation changes the codon UAU (Tyr) to UAA (stop). What type of mutation is this?

Accepted Answer

Nonsense mutation

Question 5

Which process is catalyzed by reverse transcriptase?

Accepted Answer

Synthesis of DNA from an RNA template

Question 6

If the DNA coding strand is $$5'	ext{ ATG GCC TAA }3'$$, what is the amino acid sequence produced?

Accepted Answer

Met-Ala-Stop

Question 7

Which of the following is an example of a frameshift mutation?

Accepted Answer

A single base is inserted into the coding sequence

Question 8

Which of the following is NOT a feature of the genetic code?

Accepted Answer

It is ambiguous, with codons coding for multiple amino acids

Question 9

A chromosome undergoes a mutation where a segment is reversed end to end. What is this type of mutation called?

Accepted Answer

Inversion

Question 10

Given the non-template DNA strand $$5'	ext{ ATG GCT TGA }3'$$, what is the mRNA sequence and the resulting amino acids?

Accepted Answer

mRNA: $$5'	ext{ AUG GCU UGA }3'$$, Amino acids: Met-Ala-Stop

Question 11

Which of the following is an exception to the central dogma of molecular biology?

Accepted Answer

RNA is reverse transcribed to DNA

Question 12

A silent mutation occurs in a gene. What is the most likely effect on the protein product?

Accepted Answer

The protein sequence is unchanged

Question 13

A patient’s karyotype reveals an extra chromosome 21. What condition does this indicate?

Accepted Answer

Down syndrome

Question 14

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

Accepted Answer

It is the same in all living organisms, with rare exceptions

Question 15

A DNA sequence changes from $$5'	ext{ ATG GAA TGA }3' to$$ $$5'	ext{ ATG GAG TGA }3'. $$What type of mutation is this and what is the effect?

Accepted Answer

Missense mutation; changes one amino acid

Question 16

Which of the following is an example of a non-coding RNA?

Accepted Answer

tRNA

Question 17

A segment of DNA is deleted from a chromosome. What is the most likely consequence?

Accepted Answer

Loss of genetic information, possibly leading to disease

Question 18

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

Accepted Answer

AUG

Question 19

A gene is transcribed and translated, but the resulting protein is nonfunctional due to a premature stop codon. Which mutation most likely occurred?

Accepted Answer

Nonsense mutation

Question 20

Which enzyme is responsible for DNA replication?

Accepted Answer

DNA polymerase

Chapter 16 – The Central Dogma: Gene Expression and Mutations

Study Guide - Practice Questions