Chapter 15 Biology

Bacterial cells that contain pGal will fluoresce blue under ultraviolet light. Which of the following is the most likely outcome of replacing the lacA gene in the E. coli lac operon with the gene encoding pGal?

• When lacY and lac Z are breaking down and transporting lactose, the bacteria will fluoresce blue under ultraviolet light

• lacZ will only produce the enzyme for breaking down galactose in the presence of ultraviolet light

• the repressor enzyme will only be able to bind to the operator under the presence of lactose

• When the regulatory gene is stimulated by lactose, it will cause the gene to fluoresce blue

• All structural genes downstream from the placement of lacA will be inhibited due to this substitution mutation.

Tags

NGSS.HS-LS1-1

For a repressible operon to be transcribed, which of the following must be true?

• A corepressor must be present.

• RNA polymerase and the active repressor must be present.

• RNA polymerase must bind to the promoter, and the repressor must be inactive and not blocking the promoter region.

• RNA polymerase cannot be present, and the repressor must be inactive.

Operons are found in the cells of which of the following types of organisms?

• prokaryotes (bacteria)

• eukaryotes (plant and animals)

• animals only

• viruses

The lac operon genes only become expressed if:

• lactose binds to the repressor

• glucose binds to the repressor

• lactose binds to the operator

• the repressor binds to the operator

What is the role of operons in prokaryote gene expression?

• It makes the genes prokaryotes be turned on

• It accounts for the regulation of gene activity in response to the needs of the cells

• To make DNA for the gene

• To make the gene turn of and off

What is the name of the stretch of DNA where RNA polymerase binds?

• operator

• promoter

• enhancer

• origin

What type of operon is the trp (tryptophan) operon?

• inducible

• repressible

• positive control

• promoible

In eukaryotes, proteins that help the RNA polymerase bind to the regulatory region for transcription are called ____________.

• transcription factors

• topoisomerase

• regulatory genes

• activators

Tags

NGSS.HS-LS1-1

In eukaryotes, a cluster of proteins (RNA polymerase II, mediator proteins, etc.) that assemble on the promoter is called the

• transcription initiation complex

• control element

• activator

• protein blobby thing

All of the following are true about histone acetylation EXCEPT

• takes place on the histone

• enzymes add a acetyl group

• when it occurs, transcription is more likely to occur

• chromatin becomes more tightly packed