ntroduction to biology, general educational information.
Unifying Principles of Modern Biology.
There are three:
A. All Organisms Are Made Up
of Cells. In 1838, a German
botanist, M. Schleiden demonstrated plant cells. In 1839,
zoologist T. Schwann demonstrated animal cells. In 1858,
pathologist R. Virchow said that cells only come from other
cells. In Chapter 3, we shall
talk of organic
molecules, and see that Amino Acids are the building
of proteins for cells -- and that throughout all
and all forms of life, from the lowest most simple
to humans, only 20 amino acids are used, and all
forms use the same. A powerful
finding showing the
of life on Earth.
B. All Organisms Obey Laws
of Physics and Chemistry.
argued that there was a "vital" force in life which
their reactions a special form. This
was refuted as
as 1898 by Buechner in Germany, who found that cells
NO special "vital" reactions; indeed, the same old
reactions that occurred outside of cells were the
occurring inside of cells. Heredity
itself, it has
been learned, is determined by the chemical structure
the "gene" molecules, dioxyribonucleic acid -- DNA.
C. All Organisms Require Energy. And
follow the laws of
Energy can change from one form to
but cannot be created or destroyed.
All natural events proceed in such a way that concentrations of energy tend
to dissipate or become random. A
Living System is a concentration
of energy, and can stay that
was ONLY by the intake of additional energy, by sunlight
or the chemical energy of food. A
cell is a complex
of systems for the transformation of energy. The
Flow of Energy is the Essence of Life, and the entire structure
of the Biosphere (chapter 55) is determined by the
energy exchanges of the groups that live in it. The hamburger
you eat, for example, is a transfer of chemical energy
from the cow whose meat it was, to you; the
series of protein molecules, came from an energy transfer to
the cow from the plants it ate; the
plants synthesized its
nutrients from converting energy from the sun.
The Forms of Life. There are about 5 million extant species.
Monera: The smallest and simplest of all organisms.
and their relatives. One celled,
the nucleus"), with no defined nucleus in their
and no other internal cellular structure. Monera
on Earth about 3.5 Billion years ago, and had sole
of the planet for 2 Billion years.
Protista: Mostly one-celled, but the cell structures
one form of Protista to another are very different.
are many different types, from simple to complex.
are Algae, Amoebas, Paramecia. They
are a type
cell called "Eukaryotes", or "truly nucleated).
of life in all the life "kingdoms" except Monera
Fungi: These organisms live much differently than the
of the world. Included are Yeasts,
live by digesting complex macromolecules into smaller
and then absorbing them.
Plantae: Are many-celled organisms that collect energy
light. They covert the light energy
and oils for use by the plant (and animals eating
Animalia: many-celled life-forms which depend on
life-forms, usually plants or animals, for their
of energy. 1.5 million species are
"kingdom", 95% of which are invertebrate, with a
of those being insects.
The Nature of Science.
Science is the seeking of principles of order in the
universe, by gathering hypothesis; if
the hypothesis is
by test and analysis, it graduates to a theory.
theory can become a principle or law. A
"hypothesis" only when it is stated in such a way that
is Testable, by observation or experiment.
of broad and basic importance has survived
number of independent tests, using diverse data, it may
a "theory". Thus a
scientific theory is one that
been subjected to and passed rigorous examination by
scientists. Science is a dynamic
of reexamination and seeking new information.
evolves, as it were.
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