BIO 150 CHAPTER 12 [THE CELL CYCLE]

Cancer

A disease characterized by uncontrolled cell division.

Binary Fission

The process by which bacterial cells divide.

Eukaryotic Chromosomes

Structures composed of chromatin; humans have 46 chromosomes in pairs.

Chromatin

A complex of DNA and protein that makes up chromosomes.

Nucleosome

A structure made of DNA wrapped around 8 histone proteins.

Karyotype

An array of chromosomes from an individual organism.

Diploid

Cells with two complete sets of chromosomes (2n).

Haploid

Cells with one set of chromosomes, such as sex cells (23 in humans).

Centromere

The region of a chromosome where the two sister chromatids are joined.

Interphase

The phase of the cell cycle that includes G1, S, and G2 phases.

Checkpoints

Points in the cell cycle where the process can be halted for accuracy.

Cyclin-dependent kinases (Cdks)

Enzymes that phosphorylate proteins to control the cell cycle.

Tumor-suppressor genes

Genes that normally inhibit cell division and prevent cancer.

Proto-oncogenes

Genes that promote cell growth; mutations can lead to cancer.

p53 protein

A tumor-suppressor protein that monitors DNA integrity and regulates the cell cycle.

G1 Phase

The first phase of interphase in the cell cycle, where the cell grows and prepares for DNA synthesis.

S Phase

The phase of interphase where DNA replication occurs, resulting in two copies of each chromosome.

G2 Phase

The second gap phase of interphase, during which the cell continues to grow and prepares for mitosis.

M Phase

The phase of the cell cycle that includes mitosis (cell division) and cytokinesis.

Prophase

The first stage of mitosis, where chromatin condenses into visible chromosomes and the nuclear membrane begins to break down.

Metaphase

The stage of mitosis where chromosomes align at the cell's equatorial plane.

Anaphase

The stage of mitosis where sister chromatids are separated and pulled to opposite poles of the cell.

Telophase

The final stage of mitosis where the separated chromosomes reach the poles, the nuclear membranes re-form, and the cell prepares to divide.