DNA & Protein Synthesis

What is the first step of DNA synthesis?

• Translation

• Transcription

• Replication

• Mutation

Answer explanation

The first step of DNA synthesis is Replication, where the DNA molecule is copied to produce two identical DNA molecules.

Which enzyme is responsible for adding nucleotides to the growing DNA strand during DNA replication?

• DNA polymerase

• Helicase

• Ligase

• RNA polymerase

Answer explanation

DNA polymerase is responsible for adding nucleotides to the growing DNA strand during DNA replication.

During protein synthesis, what is the process called when mRNA is decoded to produce a specific polypeptide?

• Transcription

• Translation

• Replication

• Mutation

Answer explanation

During protein synthesis, the process of decoding mRNA to produce a specific polypeptide is called Translation, making it the correct choice.

Which type of RNA carries amino acids to the ribosome?

• mRNA

• rRNA

• tRNA

• snRNA

Answer explanation

tRNA carries amino acids to the ribosome, making it the correct choice among the given options.

What is a mutation that involves the insertion or deletion of a nucleotide in the DNA sequence?

• Point mutation

• Frameshift mutation

• Silent mutation

• Missense mutation

Answer explanation

A frameshift mutation involves the insertion or deletion of a nucleotide in the DNA sequence, causing a shift in the reading frame. This can lead to significant changes in the resulting protein.

Tags

NGSS.HS-LS3-2

Which of the following is NOT a type of DNA mutation?

• Substitution

• Insertion

• Duplication

• Translation

Answer explanation

The correct choice is 'Translation' because it is not a type of DNA mutation. Substitution, Insertion, and Duplication are all types of DNA mutations.

Tags

NGSS.HS-LS3-2

What component of the cell's machinery performs the synthesis of a new DNA strand?

• Ribosome

• Golgi apparatus

• DNA polymerase

• Mitochondria

Answer explanation

DNA polymerase is the component of the cell's machinery that performs the synthesis of a new DNA strand.

Which of the following best describes the role of mRNA in protein synthesis?

• It brings amino acids to ribosomes.

• It carries the genetic code from DNA to the ribosome.

• It forms the main structural component of the ribosome.

• It helps in the replication of DNA.

Answer explanation

mRNA carries the genetic code from DNA to the ribosome, allowing for the translation of the genetic information into proteins.

Tags

NGSS.HS-LS1-1

Which mRNA codon is responsible for signaling the start of protein synthesis?

• UAA

• AUG

• UAG

• UGA

Answer explanation

The mRNA codon responsible for signaling the start of protein synthesis is AUG.

Which of the following best describes a codon?

• A three-nucleotide sequence in tRNA

• A three-nucleotide sequence in mRNA that codes for an amino acid

• A binding site for ribosomes on the mRNA

• A segment of DNA that encodes a protein

Answer explanation

A codon is a three-nucleotide sequence in mRNA that codes for an amino acid, making the second choice the correct description.