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

Question 1

Which of the following best explains why DNA is considered the universal genetic code among all living organisms?

Accepted Answer

All organisms use DNA to store genetic information, and the genetic code is nearly identical across species.

Question 2

A scientist wants to genetically engineer bacteria to produce a human protein. Which property of the genetic code makes this possible?

Accepted Answer

The universality of the genetic code allows genes from one species to be expressed in another.

Question 3

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

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar.

Question 4

During DNA replication, which enzyme is responsible for forming covalent bonds between nucleotides of a new DNA strand?

Accepted Answer

DNA polymerase

Question 5

If a segment of DNA has the sequence $$5'	ext{-}ATGCGT-3'$$, what is the complementary sequence on the other strand?

Accepted Answer

$$3'	ext{-}TACGCA-5'$$

Question 6

A mutation changes a codon from $$UAC ($$tyrosine) to $$UAA. $$What type of mutation is this, and what is its likely effect?

Accepted Answer

Nonsense mutation; it introduces a stop codon and likely results in a truncated, nonfunctional protein.

Question 7

Which of the following best describes the flow of genetic information in a eukaryotic cell?

Accepted Answer

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

Question 8

A polypeptide is 100 amino acids long. How many nucleotides are required to code for this polypeptide?

Accepted Answer

$$300$$

Question 9

Which of the following is NOT directly involved in the process of translation?

Accepted Answer

DNA

Question 10

What is the function of the anticodon region of a tRNA molecule during translation?

Accepted Answer

It base-pairs with a complementary codon on mRNA to ensure the correct amino acid is added.

Question 11

Which of the following best explains why frameshift mutations often have more severe effects than point mutations?

Accepted Answer

Frameshift mutations alter the reading frame, changing every amino acid downstream of the mutation.

Question 12

Which of the following is a major theme illustrated by the fact that nearly every organism shares the same genetic code?

Accepted Answer

Evolution

Question 13

A virus that infects bacteria is called a:

Accepted Answer

Bacteriophage

Question 14

Which enzyme is targeted by the anti-HIV drug AZT?

Accepted Answer

Reverse transcriptase

Question 15

Which of the following best describes the lysogenic cycle of a bacteriophage?

Accepted Answer

The viral DNA integrates into the host genome and replicates without killing the host cell.

Question 16

Which of the following is a unique feature of retroviruses like HIV?

Accepted Answer

They synthesize DNA from an RNA template using reverse transcriptase.

Question 17

A prion differs from a virus in that a prion:

Accepted Answer

Is composed only of protein, with no nucleic acid.

Question 18

Which of the following best explains why the Zika virus outbreak in Brazil was considered a global health emergency?

Accepted Answer

It caused severe birth defects and neurological problems in newborns.

Question 19

Which of the following is a real-world application of the universality of the genetic code?

Accepted Answer

Producing human insulin in bacteria for diabetes treatment.

Question 20

If a mutation changes the start codon $$AUG to$$ $$AUA$$, what is the most likely consequence?

Accepted Answer

Translation may not initiate, resulting in no protein being produced.

DNA Structure, Replication, and Viruses: Study Notes for General Biology

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