1. Biology: Exploring Life
Chapter 1
Biology: Exploring Life

3. THE SCOPE OF BIOLOGY
1.1 Life’s levels of organization define the scope of biology
Biosphere
Ecosystem
Florida coast
Community
All organisms on
the Florida coast
Population
Group of brown
pelicans
Organism
Brown pelican
Organ system
Nervous system
Organ
Brain
Tissue
Nervous tissue
Cell
Nerve cell
Organelle
Nucleus
Molecule
DNA
Atom
Spinal cord
Nerve

4. An ecosystem consists of all the organisms living in a par ticular area as well as the nonliving components
All the living organisms in an ecosystem
Make up a community

5. A population
group of individuals of a species
An individual living entity
Is an organism

6. The hierarchy continues downward with
Organ systems
Organs
Tissues
Cells
Organelles
Molecules

7. 1.2 Living organisms and their environments form interconnecting webs
1.2 Living organisms and their environments form interconnecting webs
Ecosystems cycle of chemical nutrients from the atmosphere and soil
To producers to consumers to decomposers and back to the environment

8. Energy flows one-way through an ecosystem
Energy flows one-way through an ecosystem
From the sun to producers to consumers and exits as heat
Sun
Air
CO2 O2
H2O
Chemical
energy
Inflow of
light
Loss
heat
Producers
Cycling
nutrients
Consumers
Decomposers
Soil
Ecosystem
Figure 1.2

9. 1.3
A cell
Is the basic unit of life

10. New proper ties emerge
From the complex organization of a system, such as a cell
The whole is greater than the sum of the parts

11. Contain membrane-enclosed organelles, including a nucleus
Eukaryotic cells
Contain membrane-enclosed organelles, including a nucleus
Prokaryotic cells
Lack such organelles
Nucleus
(contains DNA)
Eukar yotic
cell
Prokar yotic cell
DNA
(no nucleus)
Organelles
25,000 
Figure 1.3

12. EVOLUTION, UNITY, AND DIVERSITY
1.4 All forms of life have common features
DNA is the genetic information

13. All organisms share a common set of features Ordered structures
All organisms share a common set of features
Ordered structures
Regulation of internal conditions
Figure 1.4B
Figure 1.4C

14. Growth and development Energy use Response to environmental stimuli
Growth and development
Energy use
Response to environmental stimuli
The ability to reproduce and evolve
Figure 1.4D
Figure 1.4E

15. 1.5 The diversity of life can be arranged into three domains
1.5 The diversity of life can be arranged into three domains
Into the prokaryotic domains Bacteria and Archaea
and the eukaryotic domain Eukarya

16. Domains Bacteria and Archaea
Domains Bacteria and Archaea
SEM 3,250
Figure 1.5A
SEM 25,000
Figure 1.5B

17. Domain Eukarya includes
Domain Eukarya includes
Protists (protozoans and algae, falling into multiple kingdoms)
The kingdoms Fungi, Plantae, and Animalia
Kingdom Fungi
275
Kingdom Animalia
Protists
(multiple kingdoms)
Kingdom
Plantae
Figure 1.5C

18. 1.6 Evolution explains the unity and diversity of life
1.6 Evolution explains the unity and diversity of life
Charles Dar win synthesized the theory of evolution by natural selection
Figure 1.6A

19. Natural selection is an editing mechanism
Natural selection is an editing mechanism
organisms have inherited variations,
environmental factors favor the reproductive success of some individuals over others
then populations change over time 1 2 3
Populations with varied inherited traits
Elimination of individuals with certain traits
Reproduction of survivors

20. All organisms have adaptations
All organisms have adaptations
That enhance survival in their environment
Killer whale
Pangolin
Figure 1.6C

21. 1.7 Two main approaches to learn about nature
THE PROCESS OF SCIENCE
1.7 Two main approaches to learn about nature
Discovery Science
Scientists describe some aspect of the world and use inductive reasoning to draw general conclusions
Hypothesis-Based Science
Scientists attempt to explain observations by testing hypotheses

22. 1.8 Hypothesis-based science
A Case Study from Ever yday Life
Deductive reasoning is used in testing hypotheses as follows
If a hypothesis is correct, and we test it, then we can expect a par ticular outcome
Observations
Question
Hypothesis # 1:
Dead batteries
Hypothesis # 2:
Burnt-out bulb
Prediction:
Replacing batteries
will fix problem
Replacing bulb
Test prediction
Test falsifies hypothesis
Test does not falsify hypothesis
Figure 1.8A

23. Percent of total attacks
A Case Study of Hypothesis-Based Science
In experiments designed to test hypotheses
The use of control groups and experimental groups helps to control variables
Percent of total attacks
on artificial snakes
100 80 60 40 20
83%
17%
16%
84%
Artificial king snakes
Artificial brown snakes
Coral snakes
absent
present
Figure 1.8B
Figure 1.8C
Figure 1.8D
Figure 1.8E

24. Non-Science
Many areas of life fall outside the realm of science. Religion, philosophy, ethics, politics, astrology, etc. Science must be consistent, observable, natural, predictable, testable and tentative

25. Biology is connected to many impor tant issues in our lives
Biology is connected to many impor tant issues in our lives
Environmental problems and solutions
Genetic engineering
Medicine
Figure 1.9

26. Technology is the application of science to make life better.
Pencil, chair, cell phone, clock, computer…