RNA
single-stranded nucleic acid that contains the sugar ribose
messenger RNA
type of RNA that carries copies of the instructions for the assembly of amino acids into proteins from DNA to the rest of the cell
ribosomal RNA
type of RNA that combines with proteins to form ribosomes
transfer RNA
type of RNA that carries each amino acid to a ribosome during protein synthesis
transcription
synthesis of an RNA molecule from a DNA template
RNA polymerase
enzyme that binds to DNA, separates the DNA strands, and uses one DNA strand as a template to assemble nucleotides into a complimentary strand of RNA.
promoter
specific region of a gene where RNA polymerase binds and begins transcription
intron
sequence of DNA that is not involved in coding for protein and are cut out and discarded
exon
sequence of DNA that codes for a protein and is spliced together with other eons to form the final mRNA
polypeptide
long chain of amino acids that make proteins
genetic code
collection of codons of mRNA, each of which directs the incorporation of a particular amino acid into a protein during protein synthesis
codon
group of three nucleotide bases in mRNA that specify a particular amino acid to be incorporated onto a protein
translation
process by which the sequence of bases of an mRNA is converted into the sequence of amino acids of a protein
anticodon
group of three bases on a tRNA molecule that are complementary to the three bases of a codon of mRNA
gene expression
process by which a gene produces its product and the product carries out its function
mutation
change in the genetic material of a cell
point mutation
gene mutation in which a single base pair in DNA has been changed
frameshift mutation
mutation that shifts the "reading frame" of the genetic message by inserting or deleting a nucleotide
mutagen
chemical or physical agents in the environment that interact with DNA and may cause a mutation
polyploidy
condition in which an organism has extra sets of chromosomes
operon
in prokaryotes, a group of adjacent genes that shares a common operator and promoter and are transcribed into a single mRNA
operator
short DNA region, adjacent to the promoter of a prokaryotic operon, that binds repressor proteins responsible for controlling the rate of transpiration of the operon
transcription factor
DNA-binding proteins that control gene expression by binding sequences in regulatory regions of genes
RNA interference (RNAi)
introduction of the double-stranded RNA into cells to inhibit gene expression
differentiation
process in which cells become specialized in structure and function
homeotic gene
a class of regulatory genes that determine the identity of body parts and regions in an animal embryo. Mutations in these genes can transform one body part into another
homeobox gene
A type of homeotic gene that contains a specific DNA sequence of about 130 base pairs (the homeobox) and codes for transcription factors that activate other genes important in cell development and differentiation
Hox gene
a group of homeotic genes clustered together that determine the head to tail identity of body parts in animals. All box genes contain the homeobox DNA sequence