- anticodon: group of three bases on a tRNA molecule that are complementary to an mRNA codon
- bacteriophage: virus that infects bacteria
- base pairing: principle that bonds in DNA can form only between adenine and thymine and between guanine and cytosine
- chromatin: granular material visible within the nucleus; consists of DNA tightly coiled around proteins
- codon: three-nucleotide sequence on messenger RNA that codes for a single amino acid
- differentiation: process in which cells become specialized in structure and function
- DNA polymerase: enzyme involved in DNA replication that joins individual nucleotides to produce a DNA molecule
- exon: expressed sequence of DNA; codes for a protein
- frameshift mutation: mutation that shifts the “reading” frame of the genetic message by inserting or deleting a nucleotide
- gene: sequence of DNA that codes for a protein and thus determines a trait
- histone: protein molecule around which DNA is tightly coiled in chromatin
- hox genes: series of genes that controls the differentiation of cells and tissues in an embryo
- intron: sequence of DNA that is not involved in coding for a protein
- messenger RNA (mRNA): RNA molecule that carries copies of instructions for the assembly of amino acids into proteins from DNA to the rest of the cell
- mutation: change in a DNA sequence that affects genetic information
- nucleotide: monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base
- operator: region of chromosome in an operon to which the repressor binds when the operon is “turned off”
- operon: group of genes operating together
- point mutation: gene mutation involving changes in one or a few nucleotides
- polyploidy: condition in which an organism has extra sets of chromosomes
- promoter: region of DNA that indicates to an enzyme where to bind to make RNA
- replication: copying process by which a cell duplicates its DNA
- ribosomal RNA (rRNA): type of RNA that makes up the major part of ribosomes
- RNA polymerase: enzyme similar to DNA polymerase that binds to DNA and separates the DNA strands during transcription
- transcription: process in which part of the nucleotide sequence of DNA is copied into a complementary sequence in RNA
- transfer RNA (tRNA): type of RNA molecule that transfers amino acids to ribosomes during protein synthesistranscription
- transformation: process in which one strain of bacteria is changed by a gene or genes from another strain of bacteria
- translation: decoding of a mRNA message into a polypeptide chain