Ch. 18 Vocab Flashcards
a unit of genetic function found in bacteria and phages, consisting of a promoter, an operator, and a coordinately regulated cluster of genes whose products function in a common pathway
operon
a protein that inhibits transcription
repressor
a gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes
regulatory gene
a small molecule that binds to a bacterial repressor protein and changes its shape, allowing it to switch an operon off
corepressor
a specific small molecule that binds to a bacterial repressor protein and changes the repressor’s shape so that it can’t bind to an operator, thus switching an operon on
inducer
cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule in eukaryotic cells
cyclic-AMP
a protein that binds to DNA and stimulates gene transcription
activator
the expression of different sets of genes by cells with the same genome
differential gene expression
the attachment of acetyl groups to certain amino acids of histone proteins
histone acetylation
a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent
genomic imprinting
inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence of a genome
epicenetic inheritance
a segment of noncoding DNA that helps regulate transcription of a gene by binding a transcription factor
control elements
a segment of eukaryotic DNA containing multiple control elements, usually located far from the gene whose transcription it regulates
enhancers
a type of eukaryotic gene 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
alternative RNA splicing
a giant protein complex that recognizes and destroys proteins tagged for elimination by the small protein ubiquitin
proteasomes
a small, single-stranded RNA molecule, generated from a hairpin structure on a precursor RNA transcribed from a particular gene
microRNAs
a technique used to silence the expression of selected genes
RNA interference
the structural and functional divergence of cells as they become specialized during a multicellular organism’s development
cell differentiation
the development of body shape and organization
morphogenesis
a maternal substance, such as a protein or RNA, placed into an egg that influences the course of early development by regulating the expression of genes that affect the developmental fate of cells
cytoplasmic determinants
the process in which one group of embryonic cells influences the development of another usually by causing changes in gene expression
induction
the progressive restriction of developmental potential in which the possible fate of each cell becomes more limited as an embryo develops
determination
the development of a multicellular organism’s spatial organization, the arrangement of organs and tissues in their characteristic places in three-dimensional space
pattern formation
molecular cues that control pattern formation in an animal or plant embryonic structure by indicating a cell’s location relative to the organism’s body axes
positional information
any of the master regulatory genes that control placement and spatial organization of body parts in animals, plants, and fungi by controlling the developmental fate of groups of cells
homeotic genes
a mutation with a phenotype leading to death of an embryo or larva
embryonic lethals
a gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the offspring’s genotype
maternal effect gene
a gene that helps control the orientation of the egg
egg-polarity genes
a maternal effect gene that codes for a protein responsible for specifying the anterior end in Drosophilia
bicoid
a substance, such as Bicoid protein in Drosophilia, that provides positional information in the form of a concentration gradient along an embryonic axis
morphogens
a gene found in viral or cellular genomes that is involved in triggering molecular events that can lead to cancer
oncogenes
a normal cellular gene that has the potential to become an oncogene
proto-onco genes
a gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer
tumor-suppressor genes
in bacterial DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach
operator
