Definitions of some terms commonly used in the stem cell debate:
Adult stem cell -- A cell taken from mature tissue that can renew itself but has a limited ability to transform into specialized cell types.
Assisted reproductive technology -- Fertility treatments that involve a laboratory handling eggs or embryos, such as in vitro fertilization.
Blastocyst -- A preimplantation embryo of 30 to 150 cells.
Cloning -- The creation of an animal or person that derives its genes from a single other individual.
Differentiation -- The process by which early unspecified cells acquire the features of specific cells such as heart tissue, liver or muscle.
DNA -- The material that contains the instructions for making all the parts of the body.
Embryo -- The earliest stage of development from the single cell to implantation in the uterus.
Embryonic stem cell -- a cell from an embryo that has the potential to become a wide variety of specialized cell types.
Gene -- A unit of heredity that is a segment of DNA.
In vitro -- Done outside the body.
In vivo -- Done within the living body.
Nucleus -- The core of a cell that contains the chromosomes.
Stem cells -- Nonspecialized cells that have the capacity to self-renew and to differentiate into more mature cells.
Tissue or cell culture -- Growth of tissue in a laboratory dish for experimental research
Source: Department of Health and Human Services
Fox News First
Get all the stories you need-to-know from the most powerful name in news delivered first thing every morning to your inbox.
By entering your email and clicking the Subscribe button, you agree to the Fox News Privacy Policy and Terms of Use, and agree to receive content and promotional communications from Fox News. You understand that you can opt-out at any time.