Which of the following statements regarding cell division is false?
Cell division is common in eukaryotes but rare in prokaryotes.
Which of the following statements regarding prokaryotes is false?
Prokaryotic chromosomes are more complex than those of eukaryotes.
Eukaryotic chromosomes differ from prokaryotic chromosomes in that they
are housed in a membrane-enclosed nucleus.
Which of the following helps maintain the structure of chromosomes and control the activity of genes?
Sister chromatids are
joined together at a centromere.
Prior to mitosis, each chromosome of a eukaryotic cell consists of a pair of identical structures called
Eukaryotic cells spend most of their cell cycle in which phase
Which of the following occurs during interphase?
cell growth and duplication of the chromosomes
The genetic material is duplicated during
the S phase
The process by which the cytoplasm of a eukaryotic cell divides to produce two cells is called
Looking into your microscope, you spot an unusual cell. Instead of the typical rounded cell shape, the cell has a very narrow middle separating two bulging ends. It sort of looks like the number 8! Then you realize that this cell is
The phase of mitosis during which the mitotic spindle begins to form is
During which phase of mitosis do the chromosomes line up on a plane equidistant from the two spindle poles?
At the start of mitotic anaphase,
the centromeres of each chromosome come apart.
During which phase of mitosis does the nuclear envelope re-form?
Which of the following is a feature of plant cell division that distinguishes it from animal cell division?
formation of a cell plate
Which of the following features likely accounts for the difference between plant and animal cell cytokinesis?
Plant cells have cell walls.
Which of the following must occur for a plant or animal to grow and develop normally?
The organism must be able to control the timing and rate of cell division in different parts of its body.
When animal cells are grown in a petri dish, they typically stop dividing once they have formed a single, unbroken layer on the bottom of the dish. This arrest of division is an example of
Which of the following is probably the main factor responsible for the phenomenon of density-dependent inhibition?
physical contact of cell-surface proteins between adjacent cells
Mature human nerve cells and muscle cells
are permanently in a state of nondivision.
Which of the following statements regarding the cell-cycle control system is false?
The cell-cycle control system operates independently of the growth factors.
You are asked to culture an unidentified sample of animal tissue. You notice that the cells seem to fail to exhibit density-dependent inhibition. The source of this tissue sample is most likely
A benign tumor differs from a malignant tumor in that a benign tumor
does not metastasize
Which of the following shows the greatest promise as a cancer chemotherapy agent?