AP Bio: Unit 4 Test
Figure 1. Diagram of the cell cycle with key checkpoints Which of the following describes a mutation that would lead to an increase in the frequency of nondisjunction?
A mutation affecting checkpoint 3 proteins that prevents attachment of spindle fibers
Damaged tissue releases chemicals that activate platelets and stimulate the formation of blood clots. Which of the following predictions about the activity of platelets best describes a positive feedback mechanism?
Activated platelets release chemicals that activate more platelets.
(Figure 3. Pathway leading to cell survival, growth, and proliferation and the likely effect of drug X) Which of the following best describes the data in Figure 1 ?
At a concentration above 10 UM drug increases survival in all melanoma cell lines
Which of the following presents a correct interpretation of the changes in chromosome number depicted in Figure 1?
Chromosomes enter metaphase containing two chromatids attached by a centromere. During anaphase, the chromatids are separated, each becoming a chromosome. Cytokinesis distributes the chromosomes into two separate cells.
Figure 2: Blood insulin levels in normal mice and mutant mice after exposure to glucose Which of the following claims is most consistent with the data shown in Figure 2 ?
ESP protein does not regulate blood-sugar levels in normal mice.
A researcher claims that the epinephrine signaling pathway controls a catabolic process in muscle cells. Which of the following statements best helps justify the researcher's claim?
Glycogen phosphorylase catalyzes the conversion of glycogen to glucose-1-phosphate
During mitosis, which of the following normally occurs
Homologous chromosomes pair
Based on the experimental results, which of the following describes the most likely defect in muscle cells of patients with type 2 diabetes
IRS-1 activation is reduced at high insulin concentrations
A researcher has identified a compound that reverses the effect of drug . Based on Figure 3, which of the following best explains how the compound acts in the pathway to reverse the effects of drug ?
The DURG inhabiting the same enzyme that drug X inhabits (complex B)
Which of the following best describes how the amount of in the cell changes during phase?
The amount of DNA is halved as the cell divides into two daughter cells.
Which of the following statements best describes how a growth factor stimulates cell division from outside a cell
The growth factor binds to receptors on the cell surface, initiating a signal transduction pathway that activates specific target genes
A group of researchers cultured yeast cells in a nutrient-rich environment and a nutrient-poor environment and observed the duration of the stages of their cell cycles. The results of their study are summarized in Table 1.
168
What is the expected percent change in the content of a typical eukaryotic cell as it progresses through the cell cycle from the start of the phase to the end of the phase?
+100%
Cancer can result from a variety of different mutational events. Which of the following is LEAST likely to result in the initiation of a cancerous tumor?
A defect in a cell-cycle checkpoint prevents a cell from entering the S phase.
Based on the information presented, which of the following genetic changes in an individual without diabetes is most likely to result in a disrupted cellular response to insulin signaling similar to that of an individual with type 2 diabetes?
A deletion in the gene encoding the insulin receptor that removes only the cytoplasmic domain of the protein
Which of the following best describes the effect of insulin binding to the receptor on the osteoblast cells?
Insulin binding ultimately increases pancreatic secretion of additional insulin
Which of the following statements best describes the role of adenylyl cyclase in the epinephrine signaling pathway?
It accelerates the production of a second messenger
(Figure 3. Pathway leading to cell survival, growth, and proliferation and the likely effect of drug X) Based on Figure 2, which of the following best supports the claim that drug inhibits oxygen consumption?
Melanoma line 3 consumes statistically less oxygen per cell in the presence of drug than it does in the presence of the solvent alone
Which of the following was a positive control in the Mice experiment
Normal strain
Cyclic AMP phosphodiesterase is an enzyme that catalyzes the conversion of cyclic AMP to a different molecule. Which of the following best predicts the effect of inhibiting cyclic AMP phosphodiesterase in a muscle cell stimulated by epinephrine?
Phosphorylase kinase will remain active because protein kinase A will no longer be deactivated
Based on the model of eukaryotic cell cycle regulation shown in the figure, which of the following best describes the effect of a drug that blocks the production of the mitotic cyclin?
The cell would be prevented from entering mitosis, and the cell would stop dividing
Cancer cells behave differently than normal body cells. For example, they ignore signals that tell them to stop dividing
The environment contains mutagens that induce mutations that affect cell-cycle regulator proteins.
Which of the following outcomes will most likely result from the irreversible binding of GDP to a G protein?
The intracellular concentration of glycogen will increase
Which of the following is a valid interpretation of the experimental results that explains how individuals with type 2 diabetes differ from individuals without diabetes
The relatively low levels of glucose uptake in individuals with type 2 diabetes indicate that mobilization of GLUT4 to the cell surface is reduced in muscle cells of those individuals
Researchers studying cell cycle regulation in budding yeast have observed that a mutation in the CDC15 gene causes cell cycle arrest in telophase when the yeast cells are incubated at an elevated temperature. Which of the following statements best predicts the effect of the cell cycle arrest on proliferating yeast cells?
The yeast cells will replicate their chromosomes but will fail to complete cytokinesis.
