Mitotic Spindles
These structures attach to kinetochores and help pull sister chromatids toward opposite poles.
What are kinetochore microtubules?
The G1/S checkpoint has this function.
What is assessing DNA damage, cell size, nutrients, and growth factors before DNA replication?
Cyclins are this and have this function.
What are regulatory proteins that bind to CDKs to help control progression through the cell cycle?
This disease occurs when cells lose normal control over cell division.
What is cancer?
Binary fission is this.
What is the process by which prokaryotic cells divide into two cells?
These microtubules overlap with those from the opposite spindle pole and help push the poles apart.
What are nonkinetochore microtubules?
The G2/M checkpoint has this function.
What is checking whether DNA has been replicated accurately and whether DNA damage is present before mitosis?
Cyclin-dependent kinases (CDKs) are this and have this function.
What are enzymes that phosphorylate target proteins and are active when bound to cyclins?
A tumor is this.
What is a rapidly growing mass that can form when cells divide uncontrollably?
Most prokaryotes have this type of chromosome.
What is a single, circular DNA molecule?
During anaphase, these proteins help move kinetochore microtubules poleward.
What are motor proteins?
The mitotic spindle checkpoint has this function.
What is checking whether chromosomes are properly attached to the mitotic spindle before anaphase?
The function of M cyclin.
What is binding to Cdk1 and helping drive the transition from G2 into mitosis?
Metastasis allows this to occur.
What is cancer cells spreading and forming new tumors in other parts of the body?
The origin of replication (ori) is this.
What is the region of a bacterial chromosome where DNA replication begins?
During anaphase, nonkinetochore microtubules perform this action to help elongate the cell.
What is sliding past one another and growing in length?
A cell experiences DNA damage caused by radiation before entering S phase. The cell cycle responds to this damage in this way, and under this condition, the cell can proceed to DNA replication.
What is the G1/S checkpoint, which arrests the cell cycle to prevent DNA replication until DNA damage is repaired, allowing the cell to proceed into S phase only after the damage is corrected?
This complex promotes entry into M phase.
What is the M cyclin–Cdk1 complex?
These mutated genes can encode altered products that promote uncontrolled cell division or metastasis.
What are oncogenes?
During bacterial DNA replication, the two replicated origins move toward these parts of the cell.
What are the opposite ends, or poles, of the cell?
Kinetochore and nonkinetochore microtubules work together during anaphase in this way.
What is kinetochore microtubules move sister chromatids toward opposite poles, while nonkinetochore microtubules help push the poles apart and elongate the cell?
A cell enters metaphase, but one chromosome is not properly attached to spindle microtubules from opposite poles. This checkpoint detects the problem, and this is why the cell must delay anaphase until the attachment is corrected.
What is the mitotic spindle checkpoint detects improper chromosome attachment and delays anaphase, which ensures sister chromatids separate toward opposite poles so each daughter cell receives a complete set of genetic information and reduces the risk of unequal chromosome distribution?
After chromosomes are properly attached to the spindle, this complex promotes the separation of sister chromatids by triggering the degradation of an anaphase inhibitor.
What is the anaphase-promoting complex (APC)?
Explain how a failure of cell cycle regulation can contribute to cancer.
What are mutations in genes that regulate cell division can disrupt normal checkpoints and allow uncontrolled cell division?
Mitosis is important in the evolution of eukaryotic cell division because of this.
What are eukaryotic cells must distribute several different chromosomes to each daughter cell, and mitosis ensures that each daughter cell receives a complete set; also, mitosis evolved from an ancestral binary fission process.