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

Question 1

Which experiment led to the formulation of the one-gene, one-enzyme hypothesis?

Accepted Answer

The irradiation of bread mold Neurospora crassa and analysis of mutants unable to synthesize specific compounds.

Question 2

According to the central dogma of molecular biology, what is the correct flow of genetic information in a cell?

Accepted Answer

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

Question 3

A mutation that changes a codon specifying an amino acid into a stop codon is called:

Accepted Answer

Nonsense mutation

Question 4

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

Accepted Answer

Redundancy

Question 5

If a DNA sequence is 5'-ATG GAC TTT-3', what is the corresponding mRNA sequence?

Accepted Answer

5'-AUG GAC UUU-3'

Question 6

A base-pair substitution mutation changes a GC base pair to an AT base pair. What type of mutation is this?

Accepted Answer

Point mutation

Question 7

Which of the following is NOT a consequence of a frameshift mutation?

Accepted Answer

It always results in a silent mutation.

Question 8

What is the role of RNA polymerase during transcription?

Accepted Answer

It synthesizes RNA by matching complementary nucleotides to the DNA template strand.

Question 9

Which of the following events occurs first during bacterial transcription initiation?

Accepted Answer

Sigma binds to RNA polymerase.

Question 10

A segment of a chromosome breaks off, flips around, and rejoins. What type of chromosomal mutation is this?

Accepted Answer

Inversion

Question 11

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

Accepted Answer

AUG

Question 12

If the mRNA sequence is 5'-GAC-3', which amino acid will be incorporated during translation?

Accepted Answer

Aspartic acid

Question 13

Which of the following statements about the genetic code is FALSE?

Accepted Answer

Each amino acid is coded by only one codon.

Question 14

A mutation that does not change the amino acid sequence of a protein is called:

Accepted Answer

Silent mutation

Question 15

Which process removes introns from pre-mRNA in eukaryotes?

Accepted Answer

Splicing

Question 16

What is the function of the 5' cap added to eukaryotic mRNA?

Accepted Answer

It protects the mRNA from degradation and helps ribosomes bind for translation.

Question 17

Which of the following best explains why different alleles of the same gene can result in different phenotypes?

Accepted Answer

They produce proteins with different amino acid sequences.

Question 18

A scientist discovers a mutation that increases an organism's ability to survive and reproduce. This mutation is classified as:

Accepted Answer

Beneficial

Question 19

Which of the following is a direct result of a deletion mutation within a gene?

Accepted Answer

Frameshift mutation

Question 20

During transcription in eukaryotes, which of the following is TRUE?

Accepted Answer

Transcription occurs in the nucleus and translation occurs in the cytoplasm.

How Genes Work, Genetic Code, Mutations, and Transcription: Study Notes for Genetics Students

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