Exam 12: The Cell Cycle

Use the following information to answer the questions below. Nucleotides can be radiolabelled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labelled T nucleotides and introduced these into the culture of dividing human cells at specific times. -Once they had determined which cells were dividing, the team wanted to use a ?non-radioactive method to track whether various physiological factors (such as food or body temperature)affected the action of the pathogen. Which of the following would be effective, simple, and safe?

Which of the following is a function of those spindle microtubules that do not attach to kinetochores?

Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex?

After which checkpoint is the cell first committed to continue the cell cycle through M?

A research team began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away?

Use the following information to answer the questions below. A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. -When a cell is in anaphase of mitosis, which of the following will he see?

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

If there are 20 chromatids in a cell, how many centromeres are there?

The centromere is a region in which

What is a cleavage furrow?

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?

Use the following information to answer the questions below. The lettered circle in the figure below shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is grey. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages. -What is the correct chromosomal condition at the prometaphase of mitosis?

At which phase are centrioles beginning to move apart in animal cells?

At the M phase checkpoint, the complex allows for what to occur?

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect

Use the following information to answer the questions below. A research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. -Which of the following investigations might be most productive to show what the data on the teenagers might indicate?

You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G₁?

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to

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

The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B?