Chapter
40
Quizzes:
Self
Activities
Chapter
Cum.
Animations
Words
Appendix
Summary
Art
Art
Unit 7: Animal Form and Function
Basic Principles of Animal Form and Function
Review
Animals, like other organisms, have
that closely
serve
.
Animals must maintain adequate
–to–volume ratio exchange materials with the
environment,
and often have highly
internal
surfaces
specialized for exchanging materials.
Groups of cells with a
common
structure and function make up
, and
tissues
may be arranged in
layers
to form
, which are organized into
systems.
Animal tissues are classified into four main categories:
tissue
covers the outside of the body and lines
and
within the body; the cells are
joined.
tissue
bind and support other tissues, and contains
packed cells scattered throughout an extracellular
matrix.
is an important
protein
in connective tissue.
tissue
senses stimuli and transmits signals throughout the
animal.
tissue
is composed of long cells called muscle
capable of contracting in response to
signals. Humans have three types of muscle tissue:
,
, and
muscle.
Animals obtain energy by
and digesting food in a series of
chemical
reactions called
;
cellular
produces the energy-containing molecules
(Adenosine TriPhosphate), which powers cellular work. An animal's energy
is
partitioned
to
,
, and
.
Animals maintain an internal temperature in a process
called
.
Birds and mammals are
; their bodies are warmed mostly by heat
generated
by
, and need
metabolic rates.
Most invertebrates, fishes,
amphibians,
and
reptiles
other than
are
; they gain their heat mostly from external sources, and have
metabolic rates.
is a balance between external changes and the animal's
control mechanisms that manage the changes. A homeostatic
system
has three functional components:
,
center, and
.
A
feedback
control system functions by
the system off when end products
. In humans, the
functions as a
thermostat
for thermoregulation with many negative
pathways.
A
feedback
control system triggers mechanisms that
the
change.
Summary:
Negative and Positive Feedback
Organisms exchange heat with the environment by four
processes:
,
,
, and
.
The
system
provides insulation to reduce heat exchange with the environment.
Many marine mammals and birds have
heat
exchangers
to reduce heat loss.
Animals can also thermoregulate by
behaviors
such as
cooling,
body
,
and
.
Many animals can adjust to new temperatures over a period of time in a process known as
by adjusting metabolism or
insulation.
Some animals save energy in difficult conditions by entering a state called
, where metabolism decreases. Many small mammals and birds exhibit daily
adapted to their feeding
patterns.
is long-term torpor that is an adaptation to
winter
cold and food scarcity, while
is summer torpor that enables animals to survive heat and drought conditions.
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May 25, 2007
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