How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle?
D) The daughter cells have the same number of chromosomes and the same amount of DNA.
The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this?
E) a plant cell undergoing cytokinesis
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
A) the fibers of the mitotic spindle.
Which of the following are primarily responsible for cytokinesis in plant cells?
B) Golgi-derived vesicles
Which of the following organisms does not reproduce cells by mitosis and cytokinesis?
Chromosomes first become visible during ____ of mitosis.
The correct sequence of steps in the M phase of the cell cycle is
C) prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis.
During which phases of mitosis are chromosomes composed of two chromatids?
E) from G2 of interphase through metaphase
Which of the following is false regarding the bacterial chromosome?
C) its centromeres uncouple during metaphase of mitosis
In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis?
D) B and C only
Movement of the chromosomes during anaphase would be most affected by a drug that
D) prevents shortening of microtubules.
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 was the nucleus with 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. Those cells would have ____ picograms at the end of the S phase and ____ picograms at the end of G2.
D) 16; 16
The somatic cells derived from a single-celled zygote divide by which process?
Cytoskeletal elements play important roles in cell division. The mitotic spindle apparatus is made of ____ and pulls sister chromatids apart, whereas the contractile ring is made of ____ and required for the separation of daughter cells at the end of the mitotic phase of the cell cycle.
B) microtubules; actin microfilaments
Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis?
If mammalian cells receive a go-ahead signal at the G1 checkpoint, they will
B) complete the cycle and divide.
Cells that are in a nondividing state are in which phase?
What causes the decrease in the amount of cyclin at a specific point in the cell cycle?
D) its destruction by a process initiated by the activity of MPF complexes
What is the name of enzymes that control the activities of other proteins by phosphorylating them?
C) protein kinases