Cancer and Cell Divison

Zygote

Fertilized egg.

Differentiation

A process that creates special structures and functions.

Stem Cells

Undifferentiated cells that can become differentiated into one or more types of specialized cells.

Embryonic Stem Cells

Cells that have never differentiated.

Adult Stem Cells

Cells found in adult bone marrow that are partially differentiated and can become bone, blood, cartilage, fat, and connective tissue.

Gastrula

Embryo with three differentiated germ layers.

Organogenesis

The process of body organ and organ system formation that follows gastrulation.

Organism

One individual member of a species.

Organ System

Set of organs working together for a common function. Example is the digestive system.

Organ

Set of tissues working together for a common function. Example is the stomach.

Tissue

Group of cells working together for a common function. Example is muscle tissue.

Cell

Most basic unit of life that has all the characteristics of life. Example is a muscle cell.

Cell Cycle

A repeated pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells.

Interphase

Cell growth.

G1 Phase

Gap 1 phase, cell grows and makes proteins.

S Phase

Synthesis phase, DNA replication occurs, doubling the number of chromosomes.

G2 Phase

Gap 2 phase, more cell growth and protein synthesis.

Mitosis

The division phase of the cell cycle where one cell becomes two identical daughter cells.

Cytokinesis

Cytoplasm separation which begins at the end of mitosis. 

Chromosome

One long continuous thread of DNA that consists of thousands of genes and regulatory information.

Gene

A section of DNA that contains the instructions for making a protein.

Chromosome Number in the Body

46.

Chromatid

One half of a duplicated chromosome.

Sister Chromatids

Two identical chromatids.

Centromere

Region of the condensed chromosomes that looks pinched.

Telomere

Ends of the DNA molecule.

Prophase

Chromosomes condense and are visible as sister chromatids in X shapes. The nuclear membrane disappears. Spindle fibers form out of centrioles.

Metaphase

Spindle fibers connect to the centromere of each sister chromatid. Chromosomes line up in the middle of the cell.

Anaphase

Sister chromatids separate, pulling away from each other and becoming individual chromosomes. Chromatids move to opposite ends of the cell.

Checkpoint

Critical point where stop and go signals can regulate the cycle. Occurs at the end of G2, middle of M, and end of G1.

Apoptosis

Programmed cell death.

Cancer

Uncontrolled cell division.

Benign Tumors

Abnormal cells that typically remain clustered together. May be harmless and easily removed.

Malignant

Cancer cells that break away from the tumor and move to other parts of the body, forming more tumors.

Metastasize

Spreading of disease from one organ to others.

Carcinogens

Cancer-causing agents, chemicals that cause cancer by mutating DNA.