Unifying Themes of Life

1. UNIFYING
THEMES OF LIFE

2. THEMES OF LIFE
- basic ideas that apply to all
organisms
- connects many things in
the exploration of life

3. 1. BIOLOGICAL SYSTEMS
• SYSTEM
– has properties/ functions based on the arrangement
and interactions of its parts
– together, the parts of our body enables us to move
Example: Organ System
• contraction of muscles
attached to bones causes
movement
•blood vessels then supply
these parts with oxygen and
food

4. 1. BIOLOGICAL SYSTEMS
• Ecosystem
– organisms in the ecosystem require a steady
supply of certain chemicals to live
Chemicals are returned to the soil by
bacteria and fungi that decompose
the wastes and remains of plants and
animals, recycling nutrients and
enriching the soil for future growth.
animals acquire most
of the chemicals they
need by eating plants
or other animals
plants obtain most
of their necessary
chemicals from the
soil, water and air

5. 1. BIOLOGICAL SYSTEMS
• Interaction of organisms with each other and
with the nonliving environment put the
system in ecosystem
*The biological systems theme applies to all
levels of life from the biosphere all the way
down to the molecules in cells

6. 2. THE CELLULAR BASIS OF LIFE
• All organisms are
made of cells
• Levels of
organization:
- cell
- tissue
- organ
- system
- organism

7. 2. THE CELLULAR BASIS OF LIFE
• Most multicellular organisms have cells
that are specialized for different functions
Muscle cells
Contract and enable us to move
Nerve cells
Transmit impulses that control our muscles

8. 2. THE CELLULAR BASIS OF LIFE
• A multicellular organism’s development and
survival are based on the functions and
interactions of its many cells
* The cellular basis of life is a theme you will
encounter often as you explore the living world

9. 3. STRUCTURE AND FUNCTION
• The relationship between structure and
function is apparent in the entire organism
and the physiological systems that serve
them
• The structure determines function, function
reflects structure
– Technically, they are inseparable

10. 3. STRUCTURE AND FUNCTION
The aerodynamic shape of the bird’s wing
Elliptical Wings
Birds that must maneuver in forested habitats have
elliptical wings.
Elliptical wings are slotted between primary feathers to
prevent stalling at low speeds
The small chickadee can change its course within
0.03 seconds.
High-Aspect Ratio
Birds that feed on the wing or make long migrations
have high-speed wings.
These wings sweep back and taper to a slender tip;
this reduces turbulence.
They are flat in section and lack wing-tip slotting.
Elliptical
Wings (Fly
catcher)
High Aspect
Ratio
(Swallow)

11. 3. STRUCTURE AND FUNCTION
The aerodynamic shape of the bird’s wing
Dynamic Soaring wings
Albatrosses, gannets and other oceanic soaring birds
have long, narrow wings.
They have the highest aerodynamic efficiency of any
design, but are less maneuverable.
These birds exploit the highly reliable sea winds and
air currents of different velocities.
High-Lift Wings
Vultures, hawks, eagles, owls and other birds of prey
that carry heavy loads have wings with slotting, alulas
and pronounced camber. This produces high lift at slow
speed.
Wings of these birds have an aspect ratio
intermediate between elliptical wings and high aspect
ratio wings. Many are land soarers; broad,
slotted wings
Dynamic
Soaring Wings
(Albatross)
High- Lift
Wings
(Hawk)

12. 3. STRUCTURE AND FUNCTION
• The structure of the bird’s bones contributes to the bird’s
ability to fly
Inside the bones, an open, honeycomb-
like structure provides great strength
with little weight
Birds have long extensions of nerve cells
that control their flight muscles
These fibers make it possible for the
bird’s brain to coordinate flying
movements

13. 4. REPRODUCTION AND INHERITANCE
• “Like begets like”
– The offspring inherits units of
information called genes
from their parents
• Genes:
– Responsible for family
resemblance
– Made up of information-rich
molecules called
DNA

14. 4. REPRODUCTION AND INHERITANCE
• Each cell in the body
contains a copy of all
DNA that were
inherited from our
mother and father
– When a cell divides, it
copies its DNA and passes
this genetic information on
to each of the two cells it
produces

15. 4. REPRODUCTION AND INHERITANCE
• In humans, an egg cell from the mother
fuses with a sperm cell from the father
– This results in a fertilized cell containing a
combination of DNA from both parents
– The inherited DNA directs the transformation of the
fertilized egg into a person with his/her own eye
color, facial features and other characteristics
• *The inherited information in the form of DNA
enables organisms to produce their own kind

16. 5. ENVIRONMENTAL INTERACTIONS
• No organism is completely isolated from its
surroundings
• As part of an ecosystem, each organism
interacts continuously with its environment
– The plants obtain water and nutrients from the
soil, carbon dioxide from the air and energy
from sunlight

17. 5. ENVIRONMENTAL INTERACTIONS
• The transfer of chemicals between
organisms and their environments is a key
process in any ecosystem
– Breathing air, drinking water, eating food and
getting rid of wastes are chemical exchanges
with the environment

18. 5. ENVIRONMENTAL INTERACTIONS
• There is a constant sensing and responding to changes
in the environment
The specialized leaf of the
Venus flytrap senses the
light footsteps of a soon-to-
be-digested fly
The plant responses by
rapidly folding the leaf
together

19. 5. ENVIRONMENTAL INTERACTIONS
• There is a constant sensing and responding to changes
in the environment
The sun may cause
organism to squint
The bark of an
approaching dog causes
you to turn your head
quickly

20. 6. ENERGY AND LIFE
• Moving, growing, reproducing and other activities
of life require energy
• Energy is obtained
from chemical
reactions
– Sugars, fats and
other “fuel-like”
molecules in the food
produce energy

21. 6. ENERGY AND LIFE
• Energy enters the ecosystem as sunlight
Plants are producers that convert
light energy to chemical energy
stored in food
Animals and other consumers
obtain their energy in chemical
form by eating
Energy exist in the ecosystem as
heat, which all organisms generate
as they perform work

22. 6. ENERGY AND LIFE
• Because all organisms lose energy in the
form of heat, an ecosystem cannot recycle
energy
*Life on Earth depends on a continuous supply
of energy from the sun

23. 7. REGULATION
• Organisms have the ability to regulate their
internal conditions
The thermostat of the brain reacts
whenever your body temperature
varies slightly from 37 C
◦
It then sends signals to the skin to
produce sweat. Sweating helps cool
the body
Panting is another example of
cooling mechanism. It causes
moisture from the surface of the
lungs to evaporate

24. 7. REGULATION
• The ability of mammals and birds to
regulate body temperature is another
example of homeostasis or “steady-state”
• Different mechanisms enable organisms to
regulate their internal environment despite
changes in their external environment

25. 8. EVOLUTION AND DIVERSITY
• Explains changes in organisms over long periods
of time
– Adaptation allows life forms to acquire new
characteristics in response to their environment
through the process of natural selection
Some animals
make their coats
lightened to
facilitate hiding
from predators

26. 8. EVOLUTION AND DIVERSITY
• The study of evolution is helping health professionals
understand how disease-causing bacteria
become resistant to antibiotic drugs
• Environmental issues such as water and air pollution are
changing how people think about their relationship
with the biosphere
• The population then evolves with its need for survival

27. 8. EVOLUTION AND DIVERSITY
Darker beetles are more likely to survive longer and
reproduce, passing their genes on to more offsprings

28. 8. EVOLUTION AND DIVERSITY
• Great diversity exists among the three domains of living
things:
– Bacteria, Archea and Eukarya
• Evolution explains this diversity
• Charles Darwin
and
Alfred Wallace
– Worked on the idea
of evolution by natural
selection

29. 9. SCIENTIFIC INQUIRY
• Involves asking questions about nature and then using
observations or experiments to find possible answers
to those questions
By fitting a radio transmitter
onto an Atlantic turtle,
researchers can monitor its
movement
This can help researchers
determine how large a nature
preserve must be to support a
population

30. 9. SCIENTIFIC INQUIRY
• Modern biology is changing humans’ everyday lives
– New findings about the DNA affect medicine and agriculture
– Research on the nervous system is improving the treatment of
certain mental illnesses
– The result of stem cell research, animal cloning, environmental
issues, genetically modified crops or new ways to treat diseases
show the impact of biology

31. 10. SCIENCE, TECHNOLOGY AND
SOCIETY
• Technology applies scientific knowledge in new ways
In 2013, Australia
developers created a
prototype for a bionic eye.
It sends an image to a
microchip in the brain,
allowing the user to “see”
the image

32. 10. SCIENCE, TECHNOLOGY AND
SOCIETY
• Through science, humans learn about the solution
to various problems
• The scientific method is able to give direction and
pace for every inquiry
• Technology produced machinery to lengthen the life
of perishable goods