Unit 6 Test Questions

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 cell-cycle checkpoint prevents a cell from entering the S phase

Which of the following best describes a drug interaction that directly interferes with a signal transduction pathway?

A medication enter the target cell and inhibits an enzyme that normally synthesizes a second messenger

Based on the model, which of the following mutations is most likely to result in a cell that will generate a cancerous tumor?

A mutation in the gene encoding G-PIP that results in a nonfunctional protein

The endocrine system incorporates feedback mechanism that maintain homeostasis. Which of the following demonstrates negative feedback by the endocrine system?

After a meal, blood glucose levels become elevated, stimulating beta cells of the pancreas to release insulin into the blood. Excess glucose is then converted to glycogen in the liver, reducing blood glucose levels.

Which of the following correctly labels the cells depicted int he diagram?

Cell X; macrophages, Cell Y; Helper T cells, Cell Z; B Cells

Which of the following conclusion is best supported by the data? (Bicoid and Caudal)

Bicoid protein inhibits translation of caudal mRNA

Which of the following best describes the role of mitosis in the cell cycle?

Distributing replicated chromosomes to daughter nuclei

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 human cell in prophase of mitosis can be distinguished from a human cell in prophase 1 of meiosis by the presence of

Paired homologous chromosomes in the meiotic cell

A mutation that affects Pitx1 gene function in all tissue types is most likely to be at which of the following genetic loci

Promoter

Most cells that have become transformed into cancer cells have which of the following characteristics when compared to normal, healthy cells?

Shorter cell cycle

Which of the following provides correct information about cell signaling that supports the claim?

The SRY gene produces a protein that binds to specific regions of DNA in certain tissues, which affects the development of these tissues.

Which of the following condition will most likely cause a normal body cell to become a cancer cell?

The environment contains mutagens that induce mutation that affect cell-cycle regulator proteins

Which of the following best supports the hypothesis that the difference in leaf color is genetically controlled?

The existence of yellow-leaved seedlings as well as green-leaved ones on day 14 in dish B

Which of the following best explains the contribution of the lac operon to the metabolic efficiency of a bacterial cell

The lacZ gene is highly expressed only when lactose is available

Which of the following can be best used to justify why the GFP is expressed by E. coli cells after transformation with the plasmid

The presence of arabinose in the nutrient agar activated the expression of the genes located downstream of the ara operon regulatory sequences

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 in muscle cells of those individuals

One approach to treating patients with pancreatic cancer and other cancers in which the Hedgehog protein is detected is to modify the Hedgehog signaling pathway. Which of the following is the most useful approach?

Treating patients with a membrane-soluble compound that can bind to Smo and block its activity

If chemical signals in the cytoplasm control the progression of a cell to the M phase of the cell cycle, then fusion of a cell in G1 with a cell in early M phase would most likely result in the

condensation of chromatin in preparation of nuclear division in both cells

DNA replication occirs

during the S phase of the cell cycle