AP Biology Chapter 18-19 Practice Quiz

Chapter 18 Practice Quiz

Chapter 18 Practice Quiz

A mutation that inactivates a regulatory gene of a repressible gene of a repressible operon in an E. Coli cell would result in _____.

Continuous trasncription of the structural gene controlled by that regulator

LAC operon is likely to be transcriped when

cAMP and lactose levels are both high

What must happen for a repressible operon to be transcribed?

RNA polymerase must bind to the promoter, and the repressor must be inactive

Altering patterns of gene expression in prokaryotes would most likely serve an organism's survival by ______.

Allowing an organism to adjust to changes in environmental conditions

What causes an increase in CAP activity in stimulating transcription?

A decrease in glucose and an increase in cAMP

What would occur if the repressor of an inducible operon were mutated so that it could not bind the operator?

Continuous transcription of the operon's genes

The trp repressor blocks transcription of the trp operon when the repressor ____.

Binds to tryptophan

CAP is responsible for positive regulation of lac operon because

CAP bound to the CAP-binding site increases the frequency of transcription initiation

If a yeast mutant contains many histones resistant to acetylation, what phenotype will occur?

The mutant will show low levels of gene expression

The primary difference between enhancers and promoter-proximal elements is that enhancers ____.

Enhancers are at considerable distances from the promoter; promoter-proximal elements are close to the promoter

Nerve and pancreatic cells contain different

Sets of regulatory proteins

Not long ago, it was believed that a count of the number of protein-coding genes would provide a count of the number of proteins produced in any given eukaryotic species. This is incorrect, largely due to the discovery of widespread _____.

Alternative splicing

Which mechanism is used to coordinate the expression of multiple related genes in eukaryotic cells?

The genes share a single common enhancer, which allows appropriate activators to turn on their transcription at the same time.

What is most likely to have a small protein called ubiquitin attached to it?

A cyclin protein, that usually acts in G1, in a cell that is G2

Chapter 19 Practice Quiz

Chapter 19 Practice Quiz

Which viruses contain glycoproteins

-Adenovirus

-Influenza

Which viruses contain capsids?

-Adenovirus

-Influenza

-Bacteriophage

Viruses are nonliving because they are

Not cellular

Viruses ___

Use the host cell to copy themselves and make viral proteins

What is the main structural difference between enveloped and nonenveloped viruses?

Enveloped viruses have a phospholipid membrane outside their capsid, whereas nonenveloped viruses do not have a phospholipid membrane.

Which of the following is characteristic of the lytic cycle?

A large number of phages are released at a time

Describe the lysogenic cycle of lambda phage?

The phage genome replicates along with the host genome

Which viruses have single-stranded RNA that acts as a template for DNA synthesis?

Retroviruses

What is the function of reverse transcriptase in retroviruses?

It uses viral RNA as a template for DNA synthesis

In the figure, at the arrow marked II, what enzymes are being utilized?

Host cell DNA polymerase

In the figure, when new viruses are being assembled at the point marked IV, what mediates the assembly?

Nothing; they self-assemble

Viruses use the host's machinery to make copies of themselves. However, some human viruses require a type of replicatioin that humans do not normally have. For example, humans normally do not have the ability to convert RNA into DNA. How can these types of viruses infect humans, when human cells cannot perform a particular role that the virus requires?

The viral genome codes for specialized enzymes not in the host

A virus consisting of a single strand of RNA, which is transcribed into complementary DNA, is a _____.

Retrovirus

What could use reverse transcriptase to transcribe its genome?

ssRNA