Artificial selection: the guided and intentional reproduction of individuals in a population that have desirable traits, often achieved through breeding techniques.
Backbreeding: a type of artificial selection that aims to recreate the traits of a wild-type ancestor in new individuals in a population, where the wild-type ancestor is usually extinct.
Chromosome: an organized structure that contains tightly coiled DNA of an organism.
Clone: an organism that is a near genetic copy of another organism.
CRISPR/Cas9: A naturally occurring immune system in bacteria and archaea that is programmable as a gene-editing tool.
Cryopreservation: a process by which cells, tissues, and other biological materials that are vulnerable to damage are preserved at very low temperatures.
Cytoplasm: a thick solution inside of cells, enclosed by the cell membrane but outside of the nucleus.
De-extinction: the overarching movement or practices of creating facsimiles of extinct species.
Diploid: the state of having two complete sets of chromosomes, one from each parent.
DNA: a self-replicating molecule that carries the genetic information of an organism.
DNA sequencing: see Sequencing.
DNA synthesis: see Synthesis.
Epigenetics: the study of how heritable changes are made in an organism when they cannot be explained by changes in the genetic code itself, for example, through gene expression as it is modified by environmental factors.
Eukaryotic cells: Cells that contain a nucleus and other organelles that are bound by membranes.
Gamete: a haploid male or female germ cell (for example, sperm or egg) that is able to fuse with another of the opposite sex in sexual reproduction to create a new diploid organism.
Gene: a unit of heredity that is transferred from parents to offspring; it is made up of a specific DNA sequence.
Gene editing (may also refer to genome editing): a type of genetic engineering in which DNA is deleted, inserted, or replaced in the genome of an organism.
Genetic engineering: the human manipulation of the DNA of an organism using biotechnological tools.
Genome: the complete collection of genetic material in an organism.
Germ cells: cells that give rise to the gametes (sperm and eggs) of an organism that reproduces sexually.
Haploid: the state of having a single set of unpaired chromosomes.
Induced pluripotent stem cells (iPSCs): cells that are reprogrammable to become embryonic stem cell–like.
Mitochondrion: a membrane-bound organelle found in large numbers in most eukaryotic cells that acts as the “power house” for the cell; it contains a small genome independent from that of the nucleus.
Nucleus: a membrane-bound organelle in eukaryotic cells that contains most of the cell’s genetic material.
Pluripotent: the immature state of a cell that is able to give rise to all different cell types in the body.
Polymerase chain reaction (PCR): a method of making multiple copies of a DNA sequence.
Primordial germ cells (PGCs): the predecessors of germ cells that will eventually become gametes.
Recombinant DNA: DNA that has been directly formed by combining genetic material from different organisms.
Selective breeding: a type of artificial selection in which humans purposefully breed chosen animals or plants to develop desirable traits in individuals in a population.
Sequencing (DNA sequencing): the process of deciphering the precise order of DNA bases in a genetic sequence.
Somatic cell nuclear transfer: a laboratory technique for creating an egg cell with a donor nucleus; used in cloning.
Somatic cells: any type of nonreproductive cells that form the body of an organism.
Stem cells: unspecialized cells that can differentiate into specialized cells to form specific body parts.
Synthesis (DNA synthesis): the physical creation of artificial gene sequences.
Totipotent: the immature state of a cell that is able to give rise to any different cell type in the body as well as placental cells. Embryonic cells within the first couple of divisions after fertilization are the only totipotent stem cells an organism will have.
Unextinct: the state of having been created by a de-extinction process.