Gene Expression Review

If an mRNA molecule has introns and exons in it, where is it?

• At a ribosome
• In the nucleus
• In a prokaryotic cell
• could be in the nucleus or the ribosome

Frameshift mutations are generally more severe than point mutations. Why?

• Frameshift mutations are always passed on to offspring, point mutations are not

• Frameshift mutations change many codons, a point mutation changes only one codon

• Frameshift mutations cause cancer, point mutations do not.

• Frameshift mutations and point mutations are equally severe.

Tags

NGSS.HS-LS3-2

The DNA is tightly wrapped around the histone proteins and the gene is methylated.

• The gene is silenced.

• The gene is active.

• It is impossible to tell.

• The gene is on and off at various times.

What is the non-coding portion of the mRNA transcript that is removed during processing?

• intron

• exon

• 5'cap

• poly-A tail

Which of the following does not occur in prokaryotic gene expression but does occur in eukaryotic gene expression?

• mRNA, tRNA, and rRNA are transcribed
• RNA polymerase binds to the promotor
• a poly-A tail is added to the ends of the mRNA
• Transcription can begin as soon as translation has begun even alittle

What is the effect of a nucleotide-pair substitution that results in a nonsense mutation in a gene?

• it changes an amino acid in the encoded protein
• It has no effect on the amino acid sequence of the encoded protein
• it introduces  premature stop codon into the mRNA
• it alters the reading frame of the mRNA

Tags

NGSS.HS-LS3-2

A repressor protein

• prevents DNA synthesis

• attaches to ribosomes during translation

• destroys amino acids before protein synthesis occurs

• blocks movement of RNA polymerase

How can a person's muscle cells have the same exact DNA sequences as their nerve cells even though they look and perform completely different?

• The two different cells become mutated

• The proteins expressed in each cell are different

• They actually have different DNA in the two types of cells.

• The genome of the different cells changes

Tags

NGSS.HS-LS1-1

NGSS.HS-LS1-4

The production of mature mRNA in eukaryotes involves

• cutting introns out and spicing exons together
• adding the 5' cap
• adding the 3' poly A tail
• all of these are correct

What does the inducer molecule do in an inducable operon?

• it binds to the repressor protein allowing transcription to occur
• it binds to the promoter allowing transcription to occur
• it binds to the operator and stops transcription
• it binds to the repressor and stops transcription