Ch. 18 Vocab

Question 1

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

Answer 1

operon

Question 2

a protein that inhibits transcription

Answer 2

repressor

Question 3

a gene that codes for a protein, such as a repressor, that controls the transcription of another gene or group of genes

Answer 3

regulatory gene

Question 4

a small molecule that binds to a bacterial repressor protein and changes its shape, allowing it to switch an operon off

Answer 4

corepressor

Question 5

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

Answer 5

inducer

Question 6

cyclic adenosine monophosphate, a ring-shaped molecule made from ATP that is a common intracellular signaling molecule in eukaryotic cells

Answer 6

cyclic-AMP

Question 7

a protein that binds to DNA and stimulates gene transcription

Answer 7

activator

Question 8

the expression of different sets of genes by cells with the same genome

Answer 8

differential gene expression

Question 9

the attachment of acetyl groups to certain amino acids of histone proteins

Answer 9

histone acetylation

Question 10

a phenomenon in which expression of an allele in offspring depends on whether the allele is inherited from the male or female parent

Answer 10

genomic imprinting

Question 11

inheritance of traits transmitted by mechanisms not directly involving the nucleotide sequence of a genome

Answer 11

epicenetic inheritance

Question 12

a segment of noncoding DNA that helps regulate transcription of a gene by binding a transcription factor

Answer 12

control elements

Question 13

a segment of eukaryotic DNA containing multiple control elements, usually located far from the gene whose transcription it regulates

Answer 13

enhancers

Question 14

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

Answer 14

alternative RNA splicing

Question 15

a giant protein complex that recognizes and destroys proteins tagged for elimination by the small protein ubiquitin

Answer 15

proteasomes

Question 16

a small, single-stranded RNA molecule, generated from a hairpin structure on a precursor RNA transcribed from a particular gene

Answer 16

microRNAs

Question 17

a technique used to silence the expression of selected genes

Answer 17

RNA interference

Question 18

the structural and functional divergence of cells as they become specialized during a multicellular organism’s development

Answer 18

cell differentiation

Question 19

the development of body shape and organization

Answer 19

morphogenesis

Question 20

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

Answer 20

cytoplasmic determinants

Question 21

the process in which one group of embryonic cells influences the development of another usually by causing changes in gene expression

Answer 21

induction

Question 22

the progressive restriction of developmental potential in which the possible fate of each cell becomes more limited as an embryo develops

Answer 22

determination

Question 23

the development of a multicellular organism’s spatial organization, the arrangement of organs and tissues in their characteristic places in three-dimensional space

Answer 23

pattern formation

Question 24

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

Answer 24

positional information

Question 25

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

Answer 25

homeotic genes

Question 26

a mutation with a phenotype leading to death of an embryo or larva

Answer 26

embryonic lethals

Question 27

a gene that, when mutant in the mother, results in a mutant phenotype in the offspring, regardless of the offspring’s genotype

Answer 27

maternal effect gene

Question 28

a gene that helps control the orientation of the egg

Answer 28

egg-polarity genes

Question 29

a maternal effect gene that codes for a protein responsible for specifying the anterior end in Drosophilia

Answer 29

bicoid

Question 30

a substance, such as Bicoid protein in Drosophilia, that provides positional information in the form of a concentration gradient along an embryonic axis

Answer 30

morphogens

Question 31

a gene found in viral or cellular genomes that is involved in triggering molecular events that can lead to cancer

Answer 31

oncogenes

Question 32

a normal cellular gene that has the potential to become an oncogene

Answer 32

proto-onco genes

Question 33

a gene whose protein product inhibits cell division, thereby preventing the uncontrolled cell growth that contributes to cancer

Answer 33

tumor-suppressor genes

Question 34

in bacterial DNA, a sequence of nucleotides near the start of an operon to which an active repressor can attach

Answer 34

operator