Greek mythology. In literature, a chimera is a creation of the
imagination: an impossible mixture. In biology, a chimera is an organism
that contains genetically distinct cell types. In genetics, a chimera is
an entity containing a mixture of DNA from different sources.
chromosome: An elongated structure in the nucleus of a cell that
contains DNA. In humans and anthropoid apes, there are twenty-three
pairs of chromosomes for a total of forty-six. cicatrix: A scar.
crossing over: The exchange of parts of chromosomes between chromosome
pairs during meiosis. dna: The acronym for deoxyribonucleic acid, which
encodes genetic information. endothelialization: The healing of the
inner surface of blood vessels by the cells that cover such surfaces.
forensic pathology: A branch of pathology that relates pathological
science with civil and criminal law. gene: A functional unit of heredity
that is composed of a sequence of DNA located at a specific locus or
place on the chromosome. genome: The complete complement of genes of an
organism. In humans, the genome contains approximately one hundred
thousand genes. granuloma: A growth of a mixture of specialized cells as
a result of chronic inflammation. histocompatibility: A state when two
or more organisms can share organs or tissue (e.g., identical twins).
homologous chromosome: Chromosomes that are similar with respect to
their genes and visible structure: e.g., each chromosome of a chromosome
pair. homologous transposition: The exchange of corresponding portions
of DNA between homologous chromosomes. lymphokine: An immunologically
active hormone produced by certain immune cells called lymphocytes.
meiosis: A special type of cellular division that occurs during the
creation of sex cells (eggs and sperm), resulting in each sex cell
having half the usual number of chromosomes. In humans, each sex cell
has twenty-three chromosomes. mitochondria: Self-replicating entities in
cells that produce energy. mitochondrial dna: DNA necessary for
mitochondrial replication. It is inherited only through the maternal
line. merozoite: A stage in the life cycle of some parasites that
enables the organism to disperse and infect additional cells within the
host. parasite: An organism that lives on or in another organism (or
host). A parasite does not help the host; in fact, it typically harms
the host. parasitology: A branch of biology dealing with parasites.
pathology: A branch of medical science involving the cause, the process,
the anatomic effects, and the consequence of disease. recombinant dna: A
composite molecule of DNA that has been formed in the laboratory with
DNA from separate sources. recombinant dna technology: The applied
science of separating, producing, and recombining segments of DNA or
genes. ribosomal proteins: The proteins that form a ribosome. The DNA
that codes for these proteins is species specific and is used to
identify the species of tissue (e.g., to determine if blood is human
blood or blood of a particular species of animal). ribosome: A cellular
entity responsible for manufacturing all cellular protein. transgenic:
An organism whose genome contains one or more genes from another species
(e.g., pigs containing human genes to facilitate human reception of pig
heart valves). vaccine: A substance given to an individual to produce
resistance to disease or infection. xenograft: An organ or tissue taken
from one species and transplanted into another species. Generally, a
xenograft refers to an animal organ or tissue dial is transplanted into
a human (e.g., a pig heart valve).