AP Biology: Unit - 3 - Cell Communication and Cell Cycle Practice Test

Question 1:

Which of the following would be an example of paracrine signaling in animals?

A. neurotransmitter acetylcholineB. neurotransmitter acetylcholineC. neurotransmitter norepinephrineD. growth factor

Question 2:

A signal molecule that binds to a plasma-membrane protein is a

A. ligandB. second messengerC. protein kinaseD. receptor protein

Question 3:

What is a G protein?

A. specific type of membrane-receptor proteinB. protein on the cytoplasmic side of a membraneC. membrane-bound enzymeD. relay protein

Question 4:

What do second messengers do?

A. transport a signal through the lipid bilayerB. relay a signal from the outside to the inside of the cellC. relay message from the inside of the mebrane throughout the cytoplasmD. dampen the message

Question 5:

Which of the following can activate a protein by transferring a phosphate group to it?

A. cAMPB. G ProteinC. protein kinaseD. protein phosphatase

Question 6:

Signal amplification is most often achieved by

A. an enzyme cascadeB. binding of multiple signalsC. branching pathwaysD. action of adenylyl cyclase

Question 7:

What does a protein phosphatase do?

A. removes phosphatesB. transfers phosphates from ATP to proteinsC. activates an enzyme with a signal moleculeD. all of the above

Question 8:

What is a phosphorylation cascade?

A. travelling of hormones through the airB. travelling of hormones through the bloodC. the removal of a phosphateD. a series of molecules that get phosphorylated

Question 9:

What determines whether a signal molecule binds on the surface or enters the cell?

A. sizeB. polarityC. ability to cross the membraneD. all of these are correct

Question 10:

Cyclins are small proteins that bind to and activate CDK enzymes during the process of:

A. endocytosisB. cell respirationC. osmosisD. mitosis

Question 11:

Which of the following shows the correct sequence of the cell cycle?

A. Mitosis-> G1->S->G2->cytokinesisB. S->G1-> G2-> mitosis-> cytokinesisC. cytokinesis->mitosis->G1->S->G2D. G1->S->G2->mitosis->cytokinesis

Question 12:

According to the feedback loop, what does high blood sugar promote?

A. Insulin ReleaseB. Glucagon ReleaseC. Insulin UptakeD. Glycogen Uptake

Question 13:

Which of the following phrases best describes cytokinesis?

A. division of the cytoplasmB. division of the nucleusC. division of DNAD. division of surface area

Question 14:

When a plant cell goes through cell division, _____________.

A. the 2 new nuclei are separated by the cell membrane pinching off.B. 4 new cells are formedC. a cell plate forms, dividing the 2 new nucleiD. None of the above

Question 15:

In which stage of the cell cycle do the nucleus and its contents divide?

A. synthesisB. growth/gap 1C. mitosisD. growth/gap 2

Question 16:

A student is examining a whitefish blastula cell under a microscope. Based on his observations, the student proposes that the whitefish blastula cell is in interphase.

Which of the following pieces of evidence would best support the student’s claim?

A. The genetic content of the cell exists as dispersed chromatin.B. The mitotic spindle is fully assembled, with its poles at opposite ends of the cell.C. Sister chromatids have separated and are moving toward opposite poles of the

cell.D. A cleavage furrow has formed on the cell’s surface.

Question 17:

Adenoviruses are a family of highly contagious viruses that most commonly cause illnesses of the respiratory system, such as bronchitis or pneumonia. In the first phase of an adenovirus infection, the host cell expresses several viral proteins. One of these proteins, E1B-55k, inhibits the activity of the host protein p53, a tumor suppressor that arrests the cell cycle or induces apoptosis when DNA damage is detected.

Which of the following claims is best supported by the information above?

A. E1B-55k causes infected cells to undergo programmed cell death.B. E1B-55k decreases the likelihood of apoptosis in infected cells.C. E1B-55k causes infected cells to transition out of the cell cycle and into

G0 phase.D. E1B-55k increases the likelihood of cell cycle arrest in infected cells.

Question 18:

Which of the following correctly describes how positive and negative feedback are different?

A. Negative feedback requires the detection of stimuli, while positive feedback functions independently of stimuli.

B. Positive feedback moves a system closer to its set point, while negative feedbackmoves a system further from its set point.

C. Positive feedback occurs only in response to stimuli, while negative feedback canoccur in the absence of stimuli.

D. Negative feedback reverses changes in a system, while positive feedback amplifies changes in a system.

Question 19:

The following graph shows how cellular DNA content changes over the course of a typical mitotic cell cycle in rapidly proliferating human cells.

Based on the graph, which of the following labeled phases corresponds to S phase of the cell cycle?

A. Phase A, because it is the longest phase of the cell cycle.B. Phase B, because the amount of cellular DNA is doubled during this phase.C. Phase C, because it occurs immediately after the amount of cellular DNA is

doubled.D. Phase D, because the amount of cellular DNA is halved during this phase.

Answer Key:

1. D2. A3. B4. C5. C6. A7. A8. D9. D10.D11.D12.A13.A14.C15.C16.A17.B18.D19.B