Human Genome Project (HGP)
A worldwide project, completed
in early 2000s, to determine the precise arrangement
of nucleotides in human DNA .
Traditionally, a class of vertebrates that
breathe with gills rather than lungs, live in water, and
generally lay eggs, although some bear their young
Some biologists consider the fishes a “superclass,”
and divide them into three classes: bony fishes,
such as sunfish and cod; fishes with a skeleton formed
of cartilage rather than bone, such as sharks; and
fishes that lack jaws, such as lampreys.
✥ Fishes are cold-blooded animals.
The transplantation of animal tissue or organs from
one species to another.
✥ With the shortage of human organs available for
transplant, some work has been done to use pig and
nonhuman primate tissues and organs instead. Some
critics charge that this could lead to new, dangerous
forms of disease if a pathogen that now only affects
animals becomes communicable among humans.
A branch of genitics that studies the full set of protiens encoded by a genome.
proteins are the product of information coded
for in DNA, proteomics is closely allied to the study of
The process of determining where
genes are located on individual chromosomes.
phylum (feye-luhm) plur. phyla
One of the major divisions of the kingdoms of living things; the secondlargest standard unit of biological classification.
arthropods, chordates, and mollusks are phyla.
Phyla in the plant kingdom are frequently called divisions.
The study of the function of living
things, including processes such as nutrition, movement,
A phylum, or major division of the animal kingdom. Its ab animal with no internal spine, a body made of joined segments, and a shell. Examples re
insects, spiders, centipedes, and crustaceans. There
are more species of arthropods than of any other animal
Carbohydrates that can supply energy to
Common table sugar is sucrose. Some
other sugars are fructose, which is found in fruits; lactose,
which is found in milk; and glucose, which is
the most common sugar in the bodies of animals and
In biology, a descriptive term
for organisms that require the presence of oxygen to
live. (Compare anaerobic.)
✥ Aerobic exercise, such as running, swimming, and
doing calisthenics for an extended time, is designed to
improve the body’s use of oxygen.
homologous chromosomes (huh-mol-uh-guhs)
A pair of matching chromosomes in an organism, with
one being inherited from each parent.
Animals, especially the animals of
a particular place and time.
The male sex cells in plants.
plants, pollen is produced in thin filaments in the flower
called stamens. (See fertilization and pollination.)
✥ When pollen is carried into the air by the wind, it
frequently causes allergic reactions (see allergy) in
A female gamete.
recombinant DNA technology (ree-kom-buh-nuhnt)
Techniques, usually associated with genetic engineering,
in which strands of DNA from different
sources are spliced together to form DNA for a new life
form. Gene splicing is another name for this process.
The cloning of organisms
with the goal of planting the blastula produced by
the technique into the uterus of an adult female and
thus creating a new organism.
A molecule that relays messages
in a cell from a receptor on a cell membrane to
the final destination where an action within the cell is
to take place.
In biology, the classification lower than an
order and higher than a genus.
Lions, tigers, cheetahs,
and house cats belong to the same biological family.
Human beings belong to the biological family of
The place or function of a given
organism within its ecosystem.
✥ Different organisms may compete for the same
niche. For example, in a forest there may be a niche for
an organism that can fly and eat nectar from blossoms.
This niche may be filled by some sort of bird, or an insect,
or even a mammal such as a bat.
Use by green plants of the energy
in sunlight to carry out chemical reactions, such as
the conversion of carbon dioxide into oxygen. Photosynthesis
also produces the sugars that feed the plant.
✥ Green plants depend on chlorophyll to carry
mutagen (myooh-tuh-juhn, myooh-tuh-jen)
Something that causes mutations in living things. Mutagens
include chemicals, such as drugs or toxins, and
An American author and scientist of the twentieth century who was fervently devoted to defending the natural world against pollution. Her best-known books are Silent Spring, concerning the overuse of pesticides and weed killers, and The Sea
✥ She is considered to be the founder of the modern
The biological family that includes our species, Homo sapiens.
This family has also included Neanderthals and other forerunners of today’s humans, such as Australopithecus,
Homo erectus, and Homo habilis. Today’s human beings
are the only surviving hominids.
The most common form of sugar, found extensively in the bodies of living things; a molecule composed of carbon, oxygen, and hydrogen.
✥ Glucose is involved in the production of energy
in both plants and animals.
nucleic acids (nooh-klee-ik)
Organic molecules found in the nuclei of cells. DNA and RNA, the bestknown nucleic acids, govern heredity and the chemical processes in the cell.
The compounds containing
carbon that are typically found in living systems.
✥ Generally, anything made from living systems,
such as cloth, fuels, or wood, is said to be organic. Organic
foods are grown with no fertilizer except the
organic compounds found naturally in plants and animals.
A small, ball-like structure
in the cell, made of proteins and RNA molecules,
that serves as a platform on which the cell’s proteins
The organ of a flower on
which the pollen grows.
A change in an animal as it grows, particularly a radical change, such as the transformation of a caterpillar into a butterfly.
Watson and Crick
The two twentieth-century biologists
(James D. Watson of the United States and
Francis H. C. Crick of England) who discovered the
double helix of DNA.