$$\text{DNA} \xrightarrow{\text{Transcription}} \text{mRNA} \xrightarrow{\text{Translation}} \text{Protein}$$

Question 1

Which statement best describes the function of a gene according to the central dogma of molecular biology?

Accepted Answer

A gene is a segment of DNA that is transcribed into mRNA and then translated into a protein, which determines the phenotype.

Question 2

The one-gene, one-enzyme hypothesis was supported by experiments involving mutants of Neurospora. Which result would best support this hypothesis?

Accepted Answer

Mutants lacking a single enzyme could not grow unless supplemented with the product of that enzyme's reaction.

Question 3

Which process is responsible for converting DNA information into mRNA?

Accepted Answer

Transcription

Question 4

Given the DNA sequence 5' TTATGCCTTAATCAGG 3', what is the complementary DNA strand produced during replication?

Accepted Answer

3' AATACGGAATTAGTCC 5'

Question 5

After transcription, what is the mRNA sequence produced from the DNA template strand 3' AATACGGAATTAGTCC 5'?

Accepted Answer

5' UUAUGCCUUAAUCAGG 3'

Question 6

Which of the following best explains the link between genotype and phenotype?

Accepted Answer

Genotype is the set of genes an organism carries, and phenotype is the observable traits resulting from gene expression.

Question 7

Which RNA type is directly involved in carrying amino acids to the ribosome during translation?

Accepted Answer

tRNA

Question 8

What is the correct sequence of events in the central dogma of molecular biology?

Accepted Answer

$$	ext{DNA} \xrightarrow{	ext{Transcription}} 	ext{mRNA} \xrightarrow{	ext{Translation}} 	ext{Protein}$$

Question 9

If a DNA sequence is mutated from 5' TTGCATGTCACAATAAGCT 3' to 5' TTGCATGTCACAATAAGCC 3', what type of mutation has occurred?

Accepted Answer

Point mutation

Question 10

Which property of the genetic code allows for multiple codons to code for the same amino acid?

Accepted Answer

Redundancy

Question 11

A frameshift mutation occurs when a single nucleotide is inserted into a DNA sequence. What is the most likely consequence?

Accepted Answer

All codons after the insertion are changed, potentially altering the entire protein.

Question 12

Which of the following best describes the triplet nature of the genetic code?

Accepted Answer

Each amino acid is coded by a sequence of three nucleotides called a codon.

Question 13

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

Accepted Answer

RNA polymerase

Question 14

A mutation changes the DNA sequence from TAC to TGC. What is the effect on the protein sequence?

Accepted Answer

The amino acid coded by the codon changes, potentially altering protein function.

Question 15

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

Accepted Answer

Duplication of an entire chromosome segment.

Question 16

Which of the following best describes how mutations can affect fitness?

Accepted Answer

Mutations can be beneficial, neutral, or deleterious depending on their effect on phenotype.

Question 17

Which of the following is NOT a type of RNA involved in protein synthesis?

Accepted Answer

dRNA

Question 18

If a mutation causes a premature stop codon in the mRNA, what is the most likely outcome?

Accepted Answer

The protein will be shorter and likely nonfunctional.

Question 19

Which of the following best explains why knowing the genetic code is valuable in medicine?

Accepted Answer

It enables researchers to identify mutations that cause genetic diseases and develop targeted therapies.

Question 20

Given the mRNA sequence 5' CA AUG UCU CAG UGA CCU 3', use the genetic code to determine the amino acid sequence.

Accepted Answer

Met - Ser - Gln

How Genes Work: The Central Dogma and the Genetic Code

Study Guide - Practice Questions