Term |
Definition or Description |
Organism |
A structure containing the genetic code for
reproduction. |
Species |
A group of organisms capable of breeding to produce
fertile offspring; e.g., Ursos arctos (brown bear). |
Population |
A group of individuals in a species that live in a
defined habitat. |
Cell |
An assembly of fragile molecules, enclosed within a
semi-permeable membrane, which show some or all the
other characteristics of living things. * |
Homeostasis |
The maintenance of a constant internal environment
despite changes in the external environment. |
Excretion |
The removal of waste products of cellular metabolism. |
Movement |
The change in position of whole or part of a living
organism. |
Respiration |
The enzyme-controlled release of energy, in the form
of ATP, by the oxidation of organic compounds. |
Reproduction |
The formation of new organisms to ensure the survival
of the species. |
Irritability |
The ability to detect and respond to changes in the
external environment. |
Nutrition |
The processes by which chemical energy is obtained
and assimilated. |
Growth |
The irreversible increase in dry mass of an organism
via biosynthesis and mitotic cell division. |
Enzyme |
A catalytic protein. |
Diffusion |
The net movement of particles down the concentration
gradient; i.e., from high to low concentration. |
Active
transport |
The net movement of solute particles, across a
semi-permeable membrane, against the concentration
gradient; i.e., from low to high concentration. |
Osmosis |
The net movement of water particles, across a semi-
permeable membrane, down the concentration gradient;
i.e., from high to low concentration. |
Term |
Definition or Description |
Autotroph |
An organism which biosynthesizes its chemical energy
from inorganic compounds. |
Heterotroph |
An organism which obtains its chemical energy from
the organic compounds produced by other organisms. |
Herbivores &
Carnivores |
Ingestive heterotrophs which obtain their chemical
energy from living organisms. |
Saprotrophs |
Absorptive heterotrophs which obtain their chemical
energy from dead organisms and their excretions. |
Food chain |
A series of organisms through which chemical energy
is transferred by feeding. # |
Trophic level |
The position of an organism in a food pyramid. |
Limiting
factor |
Any variable which reduces the rate of a biological
process from its possible maximum. |
Gene |
The basic unit of inheritance; in molecular terms,
it is the sequence of DNA nucleotides which codes for
the synthesis of one polypeptide. $ |
Allele |
One of a number of alternative forms of a gene. |
Genotype |
The allele(s) present for a specific characteristic. |
Phenotype |
The physical or chemical expression of the genotype. |
Dominant
allele |
One allele of a pair which has an effect on the
phenotype when homozygous or heterozygous. (Shown in
a genetic diagram by a capital letter; e.g., H.) |
Recessive
allele |
One allele of a pair which has an effect on the
phenotype when homozygous. (Shown in a genetic
diagram by a small letter; e.g., h.) |
Codominance |
When both alleles in a heterozygous individual are
expressed in the organism's phenotype. |
Sex-linked
allele |
An alternative form of a gene which is carried on a
sex chromsome. |
Homozygous |
Where two alleles for a characteristic are the same
(e.g., HH or hh). |
Heterozygous |
Where two alleles for a characteristic are different
(e.g., Hh). |