Life 120 Chapter 9 – Flashcards

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

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

In eukaryotic cells, chromosomes are composed of DNA

What is produced if a cell divides by mitosis but does not undergo cytokinesis?

Humans produce skin cells by mitosis and gametes by meiosis. The nuclei of skin cells produced by mitosis will have

Compared to most prokaryotic cells, eukaryotic cells typically have

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

If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis?

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

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

What are primarily responsible for cytokinesis in plant cells but not in animal cells?

Movement of the chromosomes during anaphase would be most affected by a drug that prevents

Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA?

A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G2?

The beginning of anaphase is indicated by what?

During which phase of mitosis do the chromatids become chromosomes?

What is a cleavage furrow?

Using what techniques would enable your lab group to distinguish between a cell in G2 and a cell from the same organism in G1?

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?

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. What would result if colchicine is added to a sample of cells in G2?

Motor proteins require what to function in the movement of chromosomes toward the poles of the mitotic spindle?

When a cell is in late anaphase of mitosis, what will we see?

Cells from advanced malignant tumors often have very abnormal chromosomes as well as an abnormal number of chromosomes. What might explain the association between malignant tumors and chromosomal abnormalities?

Which is the first checkpoint in the cell cycle where a cell will be caused to exit the cycle if this point is not passed?

What is released by platelets in the vicinity of an injury?

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

What is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?

Which of the following triggers the cell's passage past the G2 checkpoint into mitosis?

The cyclin component of MPF is destroyed toward the end of which phase?

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

The MPF protein complex turns itself off by

Density-dependent inhibition is explained by what?

What is true concerning cancer cells?

What describes cyclin-dependent kinase (Cdk)?

Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor?

Why do neurons and some other specialized cells divide infrequently?

What most accurately describes a cyclin?

All cell cycle checkpoints are similar in which way?

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

Anchorage dependence of animal cells in vitro or in vivo depends on what?

Researchers 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?

For a chemotherapeutic drug to be useful for treating cancer cells, what is most desirable?

You have a series of cells, all of which were derived from tumors, and you first need to find out which ones are malignant. What could you do?

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

What does not occur during mitosis?

A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in

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