Which statement best explains why RNA is needed in protein synthesis instead of DNA directly leaving the nucleus?

• A. DNA is too large to leave the nucleus safely

• B. DNA cannot pair with ribosomes

• C. DNA only carries amino acids, not instructions

• D. DNA lacks codons

A mutation changes an mRNA codon from AUG to UAG. What effect will this most likely have on protein synthesis?

• It will cause continuous translation.

• It will insert the amino acid leucine instead.

• It will stop protein synthesis prematurely.

• It will have no effect.

Tags

NGSS.HS-LS3-2

If a DNA strand reads TAC GGC TTA, what is the correct mRNA transcript?

• A. AUG CCG AAU

• B. ATG GGC TTA

• C. UAC GGC UUA

• D. AUG GGC UUA

Tags

NGSS.HS-LS3-1

Why is the start codon AUG critical in protein synthesis?

• It codes for the amino acid stop.

• It ensures transcription begins correctly.

• It signals translation to begin with methionine.

• It pairs tRNA with uracil.

Which best describes the role of tRNA during translation?

• Carrying the DNA code

• Matching anticodons with codons to bring amino acids

• Attaching to RNA polymerase

• Forming ribosome structures

If a ribosome failed to recognize the STOP codon, what would happen to the polypeptide chain?

• It would be released prematurely.

• It would continue growing abnormally.

• It would fold correctly into a protein.

• It would not initiate translation.

A scientist observes that a strand of mRNA is missing nucleotides. Which process was most likely disrupted?

• DNA replication

• Transcription

• Translation

• Protein folding

Which property of RNA allows it to leave the nucleus more easily than DNA?

• It has a double helix structure.

• It is more stable than DNA.

• It is single stranded and smaller.

• It contains thymine instead of uracil.

Which of the following demonstrates the central dogma?

• RNA → DNA → protein

• Protein → RNA → DNA

• DNA → RNA → protein

• Protein → DNA → RNA

A substitution mutation changes a codon but results in the same amino acid. What type of mutation is this?

• Missense

• Nonsense

• Frameshift

• Silent

Tags

NGSS.HS-LS3-2