| A | B |
|---|
| Transformation | The process in which one strain of bacteria had apparently been changed into another. |
| Bacteriophage | A virus that infects bacteria. |
| Nucleotide | Units that make up DNA. |
| Base Pairing | The principle that hydrogen bonds can form only between certain base pairs. |
| Chromatin | A substance made of DNA and protein, tightly packed together. |
| Histone | DNA that is tightly coiled around protein, and makes up chromatin. |
| Replication | The process of which DNA duplicated. |
| DNA Polymerase | The principal enzyme involved in DNA replication. |
| Gene | Coded DNA instructions that control the production of proteins within a cell. |
| Messenger RNA | RNA molecules that carry copies of instructions needed for assembling amino acids into proteins. |
| Ribosomal RNA | A form of RNA that helps make up ribosomes. |
| Transfer RNA | RNA molecules that transfers amino acids to ribosomes. |
| Transcription | The process of copying part of the nucleotide sequence of DNA into a complementary sequence in RNA. |
| RNA Polymerase | The enzyme that starts transcription. |
| Promoter | Regions of DNA where RNA polymerase binds. |
| Intron | Sequences of nucleotides that are not involved in coding for proteins. |
| Exon | The DNA sequences that code for proteins. |
| Codon | Three consecutive nucleotides that specify a single amino acid that is to be added to the polypeptide. |
| Translation | The process of decoding an mRNA message into a polypeptide chain. |
| Anticodon | Three unpaired bases that are located in tRNA. |
| Mutation | Changes in the genetic material. |
| Point Mutation | Gene mutations involving changes in one or a few nucleotides. |
| Frameshift Mutation | Changes that shift the “reading frame” of the genetic message. |
| Polyploidy | The condition in which an organism has extra sets of chromosomes. |
| Operon | A group of genes that operate together. |
| Operator | A region of chromosome in a an operon to which the repressor binds when the operon is “turned off”. |
| Differentiation | A process in which cells become specialized in structure and function. |
| Hox Gene | A series of genes that control the differentiation of cells and tissues in the embryo. |
