activator
transcription factor that increases the rate of transcription when it binds to a promoter or enhancer
anticodon
in a tRNA, set of three nucleotides that base-pairs with an mRNA codon
bacteriophage
virus that infects bacteria
base-pair substitution
type of mutation in which a single base pair changes
codon
in an mRNA, a nucleotide base triplet that codes for an amino acid or stop signal during translation
deletion
mutation in which one or more nucleotides are lost
differentiation
process by which cells become specialized during development; occurs as different cells in an embryo begin to use different subsets of their DNA
DNA ligase
enzyme that seals gaps or breaks in double-stranded DNA
DNA polymerase
enzyme that carries out DNA replication; uses a DNA template to assemble a complementary strand of DNA
DNA replication
process by which a cell duplicates its DNA before it divides
epigenetic
refers to potentially heritable mechanisms that stably alter gene expression without changing the DNA sequence
exon
nucleotide sequence that remains in the RNA after post-transcriptional modification
gene
chromosomal DNA sequence that encodes an RNA or protein product
gene expression
multistep process by which the information in a gene guides assembly of an RNA or protein product; transcription produces RNA, translation produces proteins.
genome
an organism’s complete set of genetic material
homeotic gene
type of master gene; its expression triggers formation of a specific body part during development
insertion
mutation in which one or more nucleotides become inserted into DNA
intron
nucleotide sequence that intervenes between exons and is removed during post-transcriptional modification
master gene
gene encoding a product that affects the expression of many other genes
mutation
permanent change in a chromosome’s DNA sequence
operator
part of an operon; a DNA binding site for a repressor
operon
group of genes together with a promoter-operator DNA sequence that controls their transcription
primer
short, single strand of DNA or RNA that serves as an attachment point for DNA polymerase
promoter
a short DNA sequence that serves as a binding site for RNA polymerase
repressor
transcription factor that slows or stops transcription
RNA polymerase
enzyme that carries out transcription
semiconservative replication
describes the process of DNA replication in which one strand of each copy of a DNA molecule is new, and the other strand is from the original DNA
transcription
process in which enzymes assemble an RNA using a strand of DNA as a template
transcription factor
regulatory protein that binds to DNA and influences transcription (ex. an activator or repressor)
translation
process in which the protein-building instructions in an mRNA guide the assembly of a polypeptide