1.2 Unifying Themes of Biology
KEY CONCEPT
Unifying themes connect concepts from many
fields of biology.
1.2 Unifying Themes of Biology
I. All levels of life have systems of related parts.
A. A system is an organized group of interacting parts.
1. A cell is a system of chemicals and processes.
2. A body system includes organs that interact.
3. An ecosystem includes living and nonliving things that
interact.
1.2 Unifying Themes of Biology
B. Biologists study many different systems.
1.2 Unifying Themes of Biology
II. Structure and function are related in biology.
A. Structure- refers to what something looks like or how it is
made
B. Function- refers to the way something works or what it
does
1.2 Unifying Themes of Biology
C. Structure determines function.
1. Proteins with different structures perform different
functions.
2. Heart muscle cells have a different structure and
function than stomach muscle cells.
3. Different species have different anatomical structures
with different functions.
1.2 Unifying Themes of Biology
III. Organisms must maintain homeostasis to survive in
diverse environments.
A. Homeostasis is the maintenance of constant internal
conditions.
1. example- sweating, shivering, blood sugar
1.2 Unifying Themes of Biology
B. Behaviors and adaptations can help maintain
homeostasis.
1.2 Unifying Themes of Biology
IV. Evolution explains the unity and diversity of life.
A. Evolution is the change in living things over time.
1. The genetic makeup of a population of a species
changes.
2. Evolution can occur through natural selection of
adaptations.
3. Adaptations are beneficial inherited traits that are
passed to future generations.
1.2 Unifying Themes of Biology
B. Evolution accounts for both the diversity and the unity of
life.
1.2 Unifying Themes of Biology
What are the four themes of biology?
•
•
•
•
Systems
Structure and Function
Homeostasis
Evolution
13.1 Ecologists Study Relationships
For each of the following descriptions,
indentify which theme of biology is
being described.
13.1 Ecologists Study Relationships
A wolf has sharp teeth for catching prey.
13.1 Ecologists Study Relationships
Over time, the colors of this species of
moth have changed, and it now blends
in very nicely to the leaves of a tree.
13.1 Ecologists Study Relationships
When a person eats a lot of sugar, their
body produces insulin to maintain the
body’s blood sugar level.
13.1 Ecologists Study Relationships
These fish interact with one another and
with the algae, insects, water and sunlight
that are in the river.
13.1 Ecologists
Relationships
These
leavesStudy
are really
big so that they
can capture a lot of sunlight.
13.1
Relationships
AllEcologists
of these Study
organs
work together
to
break down food and absorb energy.
13.1
Ecologists
Study Relationships
This
dog is panting
to keep itself
cool.
13.1
Ecologists
Relationships
These
cacti Study
a very
good at conserving
water, an adaptation that allows them to
live in very hot places.