Unit 6 AP Bio

Introns are significant to biological evolution because

• their presence allows exons to be shuffled.

• they protect the mRNA from degeneration.

A mutation in which of the following parts of a gene is likely to be most damaging to a cell?

• intron

• exon

Tags

NGSS.HS-LS3-2

Alternative RNA splicing

• is a mechanism for increasing the rate of transcription.

• can allow the production of proteins of different sizes from a single mRNA

When does translation begin in prokaryotic cells?

• as soon as transcription has begun

• once the pre-mRNA has been converted to mRNA

Why might a point mutation in DNA make a difference in the level of proteinʹs activity?

• It might substitute an amino acid in the active site.

• It might exchange one stop codon for another stop codon.

Tags

NGSS.HS-LS3-2

A frameshift mutation could result from

• a base insertion only.

• either an insertion or a deletion of a base.

• a base deletion only.

Tags

NGSS.HS-LS3-2

What does the operon model attempt to explain?

• the coordinated control of gene expression in bacteria

• the mechanism of viral attachment to a host cell

The tryptophan operon is a repressible operon that is

• turned off whenever tryptophan is added to the growth medium

• turned on only when glucose is present in the growth medium.

Tags

NGSS.HS-LS1-3

When this is taken up by the cell, it binds to the repressor so that the repressor no longer binds to the operator:

• inducer

• repressor

Transcription of the structural genes in an inducible operon

• occurs continuously in the cell.

• starts when the pathwayʹs substrate is present.