allele One of several possible forms of a gene, found on the same location on a chromosome, which can give rise to noticeably different hereditary characteristics.

amniocentesis A surgical procedure in which a syringe is used to draw a sample of the amniotic fluid surrounding a growing human fetus; by examining the fetal cells suspended in this fluid, physicians can test for possible genetic abnormalities in the fetus.

biotechnology A broad term that can include genetic engineering, reproductive technology, and the use of genetic technology to address environmental problems and to develop agricultural products.

Bt Abbreviation for the bacterium Bacillus thuringiensis. Transgenic Bt crops have a gene from the bacterium that causes them to produce a common agricultural insecticide.

chromosome A chain of genetic material in the cell nucleus, consisting of DNA, RNA, and protein. Humans have 26 pairs of chromosomes.

clone A gene, cell, bacterium, or other organism...