Bio1151b
Chapter
1
Exploring Life
Biology
is the scientific study of
.
All (most?)
living
organisms exhibit these properties:
capture
from the environment, and
to that environment (including
of internal environments)
grow
and
reproduce
using
the hereditary material
(
Deoxyribonucleic
Acid)
through
a
process
called
.
a high level of
as
organized
in several
hierarchical
levels:
,
,
,
,
,
,
,
,
,
,
,
and
.
The
cell
is the basic unit for life, and contains the hereditary material
.
cells contain membrane–enclosed
, including a
DNA
–containing
.
cells
lack such
.
is the branch of biology that names and classifies species according to a system of broader and broader groups, or
.
Domain
(or Monera) and Domain
consist of prokaryotes.
Domain Eukarya, the
eukaryotes,
includes the various
kingdoms and the kingdoms
,
, and
Animalia.
Biologists use various forms of
to explore life.
In
science, scientists describe some aspect of the world and use
reasoning to draw
general
conclusions.
In
science,
scientists use
reasoning to form a general hypothesis to explain specific details of the world; this is the
method.
Observations
are used to propose
that lead to
and then
the predictions by seeing if the predictions come true.
Hypotheses must be
and
: the test results should either
or
the hypothesis.
Experiments must be designed to test the effect of one
by testing, at the same time,
groups and
groups that vary in only one variable.
If
, the hypothesis gains strength and theoretical value. If
, the hypothesis is either modified or
discarded.
Case study: mimicry.
From discovery science: many poisonous animals have
(
aposematic
) coloration as a warning to predators.
species
mimic
poisonous
ones.
Hypothesis: mimics benefit when
mistake them for harmful species (Henry
Bates
, 1862).
Prediction: mimicry should protect the king snake from
, but only in regions where
coral
snakes live.
2001: experiment with poisonous eastern
snake and mimic scarlet
snake.
Good hypotheses lead to new
, new questions, and new
predictions;
science progresses in a
of knowledge.