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

Question 1

Given the original DNA sequence 3'-AATACGGGGCGATGAAAAAAATTGCGC-5', what is the correct complementary DNA strand?

Accepted Answer

5'-TTATGCCCCGCTACTTTTTTTAACGCG-3'

Question 2

A mutation changes the DNA sequence from 3'-AATACGGGGCGATGAAAAAAATTGCGC-5' to 3'-AATACGGGGCGATGAAAAAGATTGCGC-5'. What type of mutation has occurred?

Accepted Answer

A point mutation (silent)

Question 3

Which enzyme is responsible for synthesizing a new DNA strand during DNA replication?

Accepted Answer

DNA polymerase

Question 4

During the Meselson-Stahl experiment, which result supported the semiconservative model of DNA replication?

Accepted Answer

After one generation, all DNA was of intermediate density; after two generations, both intermediate and light DNA were present.

Question 5

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

Accepted Answer

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

Question 6

Which process is used in the laboratory to amplify a specific segment of DNA, and how is this process applied in COVID-19 testing?

Accepted Answer

Polymerase Chain Reaction (PCR); it amplifies viral RNA after reverse transcription to detect SARS-CoV-2 genetic material.

Question 7

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

Accepted Answer

It carries amino acids to the ribosome and matches them to the mRNA codons.

Question 8

A mutation in a DNA sequence causes a frameshift. What is the most likely consequence for the resulting protein?

Accepted Answer

The protein will have a completely different amino acid sequence after the mutation site, likely resulting in a nonfunctional protein.

Question 9

Which stage of mitosis is characterized by the alignment of chromosomes along the metaphase plate?

Accepted Answer

Metaphase

Question 10

Which of the following statements correctly compares mitosis and meiosis?

Accepted Answer

Mitosis produces two genetically identical diploid cells, while meiosis produces four genetically unique haploid cells.

Question 11

Where does transcription occur in a eukaryotic cell?

Accepted Answer

In the nucleus

Question 12

Which level of protein structure is primarily responsible for the protein's function, and why?

Accepted Answer

Tertiary structure; it determines the overall 3D shape and active sites of the protein.

Question 13

If the DNA template strand is 3'-AATACGGGGCGATGAAAAAAATTGCGC-5', what is the mRNA sequence produced during transcription?

Accepted Answer

5'-UUAUGCCCCGCUACUUUUUUUAACGCG-3'

Question 14

Which of the following best describes the role of RNA polymerase?

Accepted Answer

It synthesizes RNA from a DNA template during transcription.

Question 15

A mutation changes a codon from UAU (tyrosine) to UAA (stop codon). What type of mutation is this, and what is the likely effect on the protein?

Accepted Answer

Nonsense mutation; it results in a truncated, likely nonfunctional protein.

Question 16

Which process occurs during both mitosis and meiosis, but only results in genetic variation in meiosis?

Accepted Answer

Crossing over

Question 17

Which of the following is a correct sequence of events during the central dogma in a eukaryotic cell?

Accepted Answer

Transcription in the nucleus, translation in the cytoplasm

Question 18

A scientist wants to amplify a small amount of DNA from a crime scene. Which technique should they use, and what is the key enzyme involved?

Accepted Answer

Polymerase Chain Reaction (PCR); Taq polymerase

Question 19

Which of the following best explains why a silent mutation does not affect the protein sequence?

Accepted Answer

Because of the redundancy of the genetic code, multiple codons can code for the same amino acid.

Question 20

Which of the following is NOT a function of mRNA?

Accepted Answer

Carrying amino acids to the ribosome

DNA, Mutations, and Central Dogma: Step-by-Step Study Guidance

Study Guide - Practice Questions