Worlds of David Darling > Children's
Encyclopedia of Science > Genetic Engineering > Glossary
GENETIC ENGINEERING:
Redrawing the Blueprint of Life
a book in the Beyond 2000 series by David Darling
Glossary
abortion
(1) The intentional ending of a pregnancy, or (2) the natural ejection of
a young fetus or embryo from a mother's body.
amino acids
Simple chemical units found in all living things. They combine to make up
proteins.
amniocentesis
A technique for analyzing the genes of a fetus. The test involves sampling
the fluid in which the fetus is located.
arthritis
A disease that causes painful swelling of one or more joints.
augmentation therapy
A form of gene therapy in which cells with healthy genes are introduced
into a patient's body to help supply a missing protein.
bone marrow
The soft substance that fills the middle of long bones and in which blood
cells are made.
carrier
A person with a disease-causing recessive gene who does not have the disease
but who can pass it on to his or her children. If both parents contribute
recessive genes, the child is likely to have the disease.
cell
The basic unit that makes up all living things and carries out all of an
organism's functions.
cell membrane
The flexible outer covering that surrounds an animal or plant cell and controls
the passage of chemicals into or out of the cell.
chromosomes
The thread-like structures in the nucleus of cells. They carry information
about the nature and function of the cell.
CVS
Short for chorion villus sampling, a technique for analyzing the genes of
a very young fetus. It involves taking a sample of cells from the chorion
– the structure that joins the fetus to the mother.
cystic fibrosis
An inherited condition in which the sufferer produces large amounts of thick,
sticky mucus. The mucus acts as a breeding ground for potentially dangerous
bacteria and must be cleared regularly.
cytoplasm
The jelly-like material surrounding the nucleus of a cell. It contains the
structures that produce the chemicals needed by the cell.
diagnosis
The identification of a disease or the cause of an ailment.
DNA
Short deoxyribonucleic acid. One of the two nucleic acids found in the nuclei
of cells. This molecule decided the composition of proteins.
dominant
Describes something that controls or is stronger than something else.
fetus
An unborn child from the end of the eighth week of pregnancy to the moment
of birth. Before the eighth week the unborn child is known as an embryo.
gene
The sequence of DNA that contains the code for a specific protein.
gene therapy
The process of altering the genetic code in diseased cells to repair genetic
defects.
genetic counseling
Advice given to potential parents about the chances that their offspring
will inherit certain genetic disorders.
genetic disease
A disorder caused by missing or faulty genes.
genetic engineering
The science of altering genetic codes in the cells of living things to produce
a change in appearance or function.
genetic screening
The process of examining the genes of an individual, before or after birth,
to predict any genetic disease.
hemophilia
An inherited condition in which the sufferer's blood lacks a substance that
causes clotting.
Huntington's chorea
A genetic disease that causes a progressive breakdown of physical and mental
health. Its effects usually start in victims around age 35 or 40.
muscular dystrophy
A genetic disease that results in a gradual weakening of a person's muscles.
mutation
An accidental change in the DNA making up a gene or chromosome. Mutations
can be caused, for example, by exposure to penetrating radiation or certain
chemicals. Only if the sperm or egg cells are affected can these changes
be passed on to the next generation.
nucleus
The place where DNA is stored inside an animal or plant cell. Instructions
that control the production of proteins are issued from the nucleus.
proteins
A group of substances that are the basis of every cell. Proteins, which
are very complex, are made up of hundreds or thousands of combinations of
amino acids.
recessive
Describes something that is pushed back by, or weaker than, something else.
retrovirus
A simple kind of virus that contains only about ten genes.
SCID
Short for severe combined immunodeficiency, a genetic disease in which few
or no white blood cells are manufactured to protect the body against infection.
sex-linked
Having to do with the sex chromosomes, X and Y.
sickle-cell anemia
A blood disease caused by a faulty gene that prevents blood cells from forming
correctly. The abnormal cells are unable to carry oxygen properly.
stem cell
A young cell that has not yet developed into a special-purpose cell.
transgenic animal (or plant)
A new type of organism created by mixing together the genes from existing
animals or plants.
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