Transcription, Translation, and Mutations

Which of the following best describes transcription?

• The process of copying DNA into an identical strand of DNA

• The process of assembling amino acids into a protein

• The process of copying DNA into mRNA

• The process of converting mRNA into tRNA

Which enzyme is responsible for synthesizing mRNA during transcription?

• DNA polymerase

• RNA polymerase

• Ligase

• Helicase

Where in the cell does transcription occur in eukaryotic cells?

• Cytoplasm

• Ribosome

• Nucleus

• Mitochondria

Before mRNA leaves the nucleus, it undergoes processing. Which of the following is NOT part of mRNA processing?

• Addition of a 5' cap

• Addition of a poly-A tail

• Removal of introns

• Conversion of uracil to thymine

What is the role of tRNA in translation?

• Carries the DNA message to the ribosome

• Brings amino acids to the ribosome based on codons in mRNA

• Helps unwind the DNA double helix

• Synthesizes mRNA from DNA

A codon consists of how many nucleotides?

• 1

• 2

• 3

• 4

Which of the following mutations would have the least effect on the final protein?

• A) Frameshift point mutation

• B) Silent point mutation

• C) Nonsense point mutation

• D) Deletion frameshift mutation

Tags

NGSS.HS-LS3-2

A frameshift mutation occurs when:

• One base is substituted for another

• A stop codon is introduced prematurely

• A single base is inserted or deleted, shifting the reading frame

• An entire codon is replaced

Which of the following statements about point mutations is true?

• They always cause a frameshift

• They change only one nucleotide in the DNA sequence

• They always result in a nonfunctional protein

• They occur only in mRNA, not in DNA

Tags

NGSS.HS-LS3-2

What would happen if a stop codon appeared too early in translation?

• The protein would be longer than normal

• The ribosome would ignore it and continue translation

• The protein would be shorter and likely nonfunctional

• The mutation would have no effect