Dictionary

recent memory See memory, short-term.

receptor 1 In cell biology, a structure on the surface of a cell or inside a cell that selectively receives and binds a specific substance. For example, there are insulin receptors and low-density lipoprotein (LDL) receptors. 2 In neurology, the terminal of a sensory nerve that receives and responds to stimuli.

receptor, visual The layer of rods and cones, the visual cells, of the retina.

recessive A genetic trait that appears only in individuals who have received two copies of a mutant gene, one copy from each parent. The individuals with a double dose of the mutated gene are called homozygotes. Their parents, each with a single dose of the mutated gene, appear normal and are called heterozygotes, or gene…

recessive, autosomal See autosomal recessive trait.

recipient In medicine, someone who is given something, such as a blood transfusion or an organ transplant, that is derived from another person (the donor).

recombinant A person with a new combination of genes, a combination not present in either parent, due to parental recombination of those genes.

recombinant clone A clone that contains recombinant DNA.

recombinant DNA molecules A combination of DNA molecules of different origin that are joined using recombinant DNA technology.

recombinant DNA technology A series of procedures that are used to join together (recombine) DNA segments. A recombinant DNA molecule is constructed from segments of two or more different DNA molecules. Under certain conditions, a recombinant DNA molecule can enter a cell and replicate there, either on its own or after it has been integrated…

recombination The trading of fragments of genetic material between chromosomes before the egg and sperm cells are created. Key features of recombination include the point-to-point association of paired chromosomes (synapsis), followed by the visible exchange of segments (crossing over) at X-shaped crosspoints (chiasmata). Recombination is the principal way of creating genetic diversity between generations. Recombination…

Recombivax-HB A vaccine that stimulates the body’s immune system to produce antibodies against the hepatitis B virus. See also hepatitis B; hepatitis B immunization.