Gene Expression
the activation of a gene that results in the formation and production of mRNA
Genome
the complete genetic material contained in an individual
Structural Gene
genes that code for polypeptides
Operator
a DNA segment that serves as a kind of "switch" by controlling the access of RNA polymerase to the promoter
Operon
a series of genes that code for specific products and the regulatory elements that control these genes
Lac Operon
a gene system whose operator gene and three structural genes control lactose metabolism in E. coli
Repressor Protein
a protein that inhibits genes from being expressed
Regulator Gene
a regulatory protein that binds to an operator an dblocks transcription of the gene of an operator
Inducer
a molecule that initiates gene expression
Euchromatin
the site of active transcription of DNA to RNA a region of DNA that is uncoiled and undergoing active transcription into RNA
Intron
a segment of a structural gene that is transcribed but not translated
Exon
sequence of nucleotides on a gene that gets transcribed and translated
Pre- mRNA
form of messenger RNA that contains both introns and extrons
Transcription Factor
regulatory proteins in eukaryotes that binds to DNA and stimulates the transcription of certian genes
Enhancer
a DNA sequence that recognizes certain transcription factors that can stimulate transcription of nearby genes
Cell Differentiation
the process by which a cell becomes specialized for a specific structure or function
Homeotic Gene
a gene that controls the development of a specific adult structure
Homeobox
a DNA sequence within a homeotic gene that regulates development in animals
Proto- Oncogene
A gene that regulates normal cell division but that can become a cancer causing oncogene as a result of mutation or recombination
Oncogene
a gene that induces cancer, or uncontrolled cell proliferation
Tumor
a growth that arises from normal tissue but that grows abnormally in rate and structure and lacks a function
Cancer
a tumor in which the cells begin dividing at an uncontrolled rate and become invasive
Tumor- Suppressor Gene
a gene that suppresses tumor formation but that, when mutated, causes a loss in cell function, which results in tumor formation
Metastasis
the spread of cancer cells beyond their original site of growth
Carcinogen
a cancer-causing substance
Carcinoma
a malignant tumor that grows in the skin or in the tissues that line organs
Sarcoma
a malignant tumor that grows in bone or muscle tissue
Lymphoma
a tumor in the lymphoid tissues
Leukemia
a progressive, malignant disease of the blood-forming organs