Cell Cycle

The cell cycle is a series of events from the time a cell forms until its cytoplasm divides.

Interphase

Interphase is the interval between mitotic divisions when a cell grows. It has three stages: G1, S, & G2. In this stage, chromosomes are loosened to allow transcription and DNA replication.

Prophase

Prophase is the first stage of mitosis. In early prophase, chromosomes begin to pack tightly in preparation for nuclear division. When prophase officially starts, the chromosomes condense even more and one of the two centrosomes move to the opposite end of cell. Then, microtubules assemble and lengthen, forming a spindle, and the nuclear envelope breaks up. Sister chromatids are then attached to opposite centrosomes.

Metaphase

In metaphase, all chromosomes are aligned midway between spindle poles. In certain types of cells, chromosomes do not line up at the metaphase plate and instead move back and forth between the poles randomly, only roughly lining up in the middle. After all cells are aligned, the cell enters anaphase.

Anaphase

In anaphase, sister chromatids separate and move toward opposite spindle poles. Because of the pressure that the chromatids put on the spindle poles, the cell gets stretched into an oval.

Telophase

In telophase, chromosomes arrive at opposite spindle poles and decondense. Because of this, two nuclei form.

Telomeres

Telomeres are noncoding repeat DNA sequences, which are repeated thousands of times, found at the ends of eukaryotic chromosomes. In telomeres, dependent cell division limits may protect against uncontrolled cell division. They keep uncontrolled cells from overrunning the body.

Cancer

Cancer cells are cells that characteristically express high levels of telomerase. Cancer a disease in which a group of abnormal cells grow uncontrollably by disregarding the normal rules of cell division. These cells can many times become dangerous or even fatal if not treated correctly.