Chp. 11 How Genes Are Controlled
Order by
31 terms
Terms | Definitions |
|---|---|
 activator | A protein that switches on a gene or group of genes. |
| adult stem cell | A cell present in adult tissues that generates replacements for nondividing differentiated cells. |
| alternative RNA splicing | A type of regulation at the RNA-processing level in which different mRNA molecules are produced from the same primary transcript, depending on which RNA segments are treated as exons and which as introns. |
| Barr body | A dense body formed from a deactivated X chromosome found in the nuclei of female mammalian cells. |
| carcinogen | A cancer-causing agent, either high-energy radiation (such as X-rays or UV light) or a chemical. |
| clone | As a verb, to produce genetically identical copies of a cell, organism, or DNA molecule. As a noun, the collection of cells, organisms, or molecules resulting from cloning; also (colloquially), a single organism that is genetically identical to another because it arose from the cloning of a somatic cell. |
| differentiation | The specialization in the structure and function of cells that occurs during the development of an organism; results from selective activation and deactivation of the cells' genes. |
| DNA microarray | A glass slide carrying thousands of different kinds of single-stranded DNA fragments arranged in an array (grid). A DNA microarray is used to detect and measure the expression of thousands of genes at one time. Tiny amounts of a large number of single-stranded DNA fragments representing different genes are fixed to the glass slide. These fragments, ideally representing all the genes of an organism, are tested for hybridization with various samples of cDNA molecules. |
| embryonic stem cell (ES cell) | Cell in the early animal embryo that differentiates during development to give rise to all the different kinds of specialized cells in the body. |
| enhancer | A eukaryotic DNA sequence that helps stimulate the transcription of a gene at some distance from it. An enhancer functions by means of a transcription factor called an activator, which binds to it and then to the rest of the transcription apparatus. See silencer. |
| gene expression | The process whereby genetic information flows from genes to proteins; the flow of genetic information from the genotype to the phenotype. |
| histone | A small protein molecule associated with DNA and important in DNA packing in the eukaryotic chromosome. |
| homeotic gene | A master control gene that determines the identity of a body structure of a developing organism, presumably by controlling the developmental fate of groups of cells. (In plants, such genes are called organ identity genes.) |
| nuclear transplantation | A technique in which the nucleus of one cell is placed into another cell that already has a nucleus or in which the nucleus has been previously destroyed. |
| nucleosome | The bead-like unit of DNA packaging in a eukaryotic cell; consists of DNA wound around a protein core made up of eight histone molecules. |
| oncogene | A cancer-causing gene; usually contributes to malignancy by abnormally enhancing the amount or activity of a growth factor made by the cell. |
| operator | In prokaryotic DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach. The binding of a repressor prevents RNA polymerase from attaching to the promoter and transcribing the genes of the operon. |
| operon | A unit of genetic regulation common in prokaryotes; a cluster of genes with related functions, along with the promoter and operator that control their transcription. |
| promoter | A specific nucleotide sequence in DNA located at the start of a gene that is the binding site for RNA polymerase and the place where transcription begins. |
| proto-oncogene | A normal gene that can be converted to a cancer-causing gene. |
| regeneration | The regrowth of body parts from pieces of an organism. |
| regulatory gene | A gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes. |
| repressor | A protein that blocks the transcription of a gene or operon. |
| reproductive cloning | Using a somatic cell from a multicellular organism to make one or more genetically identical individuals. |
| RNA interference (RNAi) | A biotechnology technique used to silence the expression of specific genes. Synthetic RNA molecules with sequences that correspond to particular genes trigger the breakdown of the gene's mRNA. |
| signal transduction pathway | In cell biology, a series of molecular changes that converts a signal on a target cell's surface to a specific response inside the cell. |
| silencer | A eukaryotic DNA sequence that functions to inhibit the start of gene transcription; may act analogously to an enhancer by binding a repressor. |
| therapeutic cloning | The cloning of human cells by nuclear transplantation for therapeutic purposes, such as the generation of embryonic stem cells. See nuclear transplantation; reproductive cloning. |
| transcription factor | In the eukaryotic cell, a protein that functions in initiating or regulating transcription. Transcription factors bind to DNA or to other proteins that bind to DNA. |
| tumor-suppressor gene | A gene whose product inhibits cell division, thereby preventing uncontrolled cell growth. |
| X chromosome inactivation | In female mammals, the inactivation of one X chromosome in each somatic cell. |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.