DNA is the molecule that gives cells and organisms their biological characteristics. Types of Nucleotides: Adenine, Cytosine, Thymine, Guanine. DNA/RNA: DNA has a double helix structure, while RNA does not. In DNA, thymine is present, whereas in RNA, uracil is present. RNA can exit the nucleus, but DNA cannot. Ribose Nucleotide does not contain thymine. Transcription is the process of copying a part of the genetic message from DNA to RNA. Translation is the process in which RNA moves from the nucleus to the cytoplasm. Genetic Code refers to the relationship between the sequence of nitrogenous bases in DNA and the sequences of amino acids that form proteins. Transcription occurs in the nucleus, while translation occurs in the cytoplasm. In prokaryotic cells, translation occurs in the cytoplasm. Synthesis of a protein with 12 amino acids: 12x3=36+3=39. DNA Replication is Semiconservative because it involves an original strand and a new one. Cell Cycle: 1. Mitosis division of the cell. 2. Cytokinesis. 3. Phase G1: protein synthesis and cell growth. 4. Phase S: replication of DNA and histones. 5. Phase G2: preparation for cell division. Genetic Engineering consists of techniques used to manipulate genetic material in order to change an organism's traits. Advances in Genetic Engineering: biological research, police investigations and forensic medicine, paternity tests, historical and archaeological studies. Transgenic Organisms: organisms with an altered genome. Vector: agents used in DNA to transfer genetic material from one cell to another. Host Cell: a living cell invaded by an infectious agent. Carrying Recombinant DNA is essential for bacteria, a plasmid, and a human cell. Uses of Recombinant DNA: genetically modifying a plant and creating vaccines. Genetic Engineering allows scientists to eliminate genes, introduce new genes, modify gene structure, and make copies of genes. Biomedical Uses of Biotechnology: Gene therapy for curing diseases with a genetic origin, prevention of genetic diseases by detecting and avoiding illnesses caused by defective genes.