Protein Synthesis

A base substitution in an intron that does not change the amino acid sequence of the polypeptide encoded by that gene would have no phenotypic effect on the organism.

• true

• false

A geneticist found that a particular mutation had no effect on the polypeptide encoded by the gene. This mutation probably involved __________.

• a silent or neutral mutation

• a missense mutation

• triploidy

• the insertion of one nucleotide

Tags

NGSS.HS-LS1-1

In eukaryotic cells, the transcription of a pre-mRNA is followed by processing. The _____ then moves to the cytoplasm, where ribosomes construct a polypeptide based on the codons in the RNA. The polypeptide is then modified, if necessary.

• mRNA

• tRNA

• rRNA

• DNA

The bonds that hold tRNA molecules in the correct three-dimensional shape are __________.

• hydrogen bonds

• ionic bonds

• covalent bonds

• none of these

Exons from the same gene could be spliced in different ways to make different mRNAs.

• true

• false

Which of the following statements correctly describes mRNA processing?

• Introns are cut out of the primary transcript, and the resulting exons are spliced together.

• Introns are cut out of the primary transcript and spliced together at the end of the transcript.

• Exons are cut out of the primary transcript and transported to the endoplasmic reticulum.

• all of these

The region of DNA to which RNA polymerase attaches and initiates transcription is the promoter, which typically extends several dozen nucleotides "upstream" from the transcription start point.

• true

• false

Which of the following catalyzes the linkage between ribonucleotides to form RNA during gene expression?

• tRNA

• reverse transcriptase

• RNA polymerase

• RNA ligase

At one point, as a cell carried out its day-to-day activities, the nucleotides TGA were paired with the nucleotides ACU. This pairing occurred __________.

• during transcription

• in a double-stranded DNA molecule

• during translation

• during replication

There are six codons that code for the amino acid leucine. This is why the code is said to be ____.

• redundant

• incomplete

• antiparallel

• directional