Exam 12: The Cell Cycle

Use the following information to answer the question(s) below. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and, therefore, can be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. -Which of the following questions might be answered by using the method described?

The following question(s) are based on the accompanying figure. -In the figure, which number represents DNA synthesis?

Use the following information to answer the question(s) below. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and, therefore, can be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. -The research team used their experiments to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that ________.

Proteins that are involved in the regulation of the cell cycle and that show fluctuations in concentration during the cell cycle are called ________.

Some cells have several nuclei per cell. How could such multinucleated cells be explained?

The cancer-causing forms of the Ras protein are involved in which of the following processes?

If the cell whose nuclear material is shown in the accompanying figure continues toward completion of mitosis, which of the following events would occur next?

Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells?

Regulatory proteins that prevent a cell from entering the S phase under conditions of DNA damage are also known as ________.

Once a cell completes mitosis, molecular division triggers must be turned off. What happens to MPF during mitosis?

A cell in late anaphase of mitosis will have ________.

If a cell has accumulated DNA damage, it is unlikely to ________.

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation. Surprisingly, this stops mitosis. Specifically, Taxol must affect ________.

In the cells of some organisms, mitosis occurs without cytokinesis. This results in ________.

Researchers pulsed rapidly dividing cultured cells with radioactive thymidine for 30 minutes. The cells were then exposed to a solution containing non-radiolabeled thymidine. Cells were analyzed at 2-hour intervals. At the 2-hour time point, no cells appeared to be dividing. Only after 4 hours did some labeled cells appear to be in M phase. This result can be explained in the following way:

A cyclin ________.

The following question(s) are based on the accompanying figure. -In the figure, which number represents the point in the cell cycle during which the chromosomes are replicated?

The microtubule-organizing center found in animal cells is an identifiable structure present during all phases of the cell cycle. Specifically, it is known as the ________.

The product of the p53 gene ________.

Exposure of zebrafish nuclei to meiotic cytosol resulted in phosphorylation of NEP55 and L68 proteins by cyclin-dependent kinase 2. NEP55 is a protein of the inner nuclear membrane, and L68 is a protein of the nuclear lamina. What is the most likely role of phosphorylation of these proteins in the process of mitosis?