_____ is the stage of the cell life cycle in which normal cellular activities occur.
It produces a very small plant, which may grow over many years into a towering tree. When it is mature, the tree makes its own seeds, and the cycle begins again. Cells have a life cycle too, called the cell cycle. The cell cycle is the normal sequence of development and division of a cell. The cell cycle consists of two main phases: one in which the cell carries out its functions, called interphase, and one in which the cell divides, which can include mitosis and cytokinesis. The events that happen during the life of a cell are called the cell cycle. As a result of mitosis and cytokinesis, the original—or parent—cell splits into two genetically identical daughter cells. In this case, the term daughter cell does not imply gender. It is a term scientists use to refer to these new cells. The Cell Cycle: Mitosis. Mitosis, the M phase, is the division of chromosomes in a eukaryotic cell. There are four stages in mitosis: (1) prophase, (2) metaphase, (3) anaphase, and (4) telophase. The cell spends the longest time in prophase. The Cell Cycle. The cell cycle is the life cycle of a cell (Figure 5.3). At the end of the cell cycle, after mitosis has taken place, the parent cell no longer exists; it has given rise to two daughter cells. There are two phases in the cell cycle, interphase and mitosis. A schematic representation of the mammalian cell cycle. In each cell division cycle, chromosomes are replicated once (DNA synthesis or S-phase) and segregated to create two genetically identical daughter cells (mitosis or M-phase). p53 is a protein that functions to block the cell cycle if the DNA is damaged. If the damage is severe this protein can cause apoptosis (cell death). 1  p53 levels are increased in damaged cells. This allows time to repair DNA by blocking the cell cycle.  A p53 mutation is the most frequent mutation leading to cancer. MPF (Maturation Promoting Factor) includes the CdK and cyclins that triggers progression through the cell cycle. p53 is a protein that functions to block the cell cycle if the DNA is damaged. If the damage is severe this protein can cause apoptosis (cell death). p53 levels are increased in damaged cells. This allows time to repair DNA by blocking the cell cycle. 1 (see legend for details). At least two types of cell cycle control mechanisms are recognized: a cascade of protein phosphorylations that relay a cell from one stage to the next and a set of checkpoints that monitor completion of critical events and delay progression to the next stage if necessary. The intent of this summary is to introduce the basics of the cell cycle, cancer, and their overlap, and then to describe the research from two laboratories that was presented in the session. A second type of cell cycle regulation, checkpoint control, is more supervisory. It is not an essential part of the cycle progression machinery. Cell cycle checkpoints sense flaws in critical events such as DNA replication and chromosome segregation (4).
Interphase and mitosis.