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

2. A Big-Billed Bird Rebounds
A Big-Billed Bird Rebounds
Brown pelicans
Are part of the web of life in their environment

3. The brown pelicans’ proximity to humans
Has meant trouble for the species
The brown pelicans’ connection to the environment
Sets the stage for the study of biology

4. THE SCOPE OF BIOLOGY
1.1 Life’s levels of organization define the scope of biology
Life’s structural hierarchy
Defines the scope of biology, the scientific study of life
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
Figure 1.1

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

6. A population
Consists of a localized group of individuals of a species
An individual living entity
Is an organism

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

8. 1.2 Living organisms and their environments form interconnecting webs
1.2 Living organisms and their environments form interconnecting webs
Ecosystems are characterized by the cycling of chemical nutrients from the atmosphere and soil
To producers to consumers to decomposers and back to the environment

9. 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

10. 1.3 Cells are the structural and functional units of life
1.3 Cells are the structural and functional units of life
A cell
Is the basic unit of life

11. New proper ties emerge
From the complex organization of a system, such as a cell

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

13. EVOLUTION, UNITY, AND DIVERSITY
1.4 The unity of life: All forms of life have common features
DNA is the genetic information
For constructing the molecules that make up cells and organisms

14. Each species’ genetic instructions
Each species’ genetic instructions
Are coded in the sequences of the four building blocks making up DNA’s two helically coiled chains A C T G
Figure 1.4A

15. 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

16. 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

17. 1.5 The diversity of life can be arranged into three domains
1.5 The diversity of life can be arranged into three domains
Organisms are grouped (classified)
Into the prokaryotic domains Bacteria and Archaea and the eukaryotic domain Eukarya

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

19. 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

20. 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

21. Natural selection is an editing mechanism
Natural selection is an editing mechanism
That occurs when populations or organisms, having inherited variations, are exposed to environmental factors that favor the reproductive success of some individuals over others 1 2 3
Populations with varied inherited traits
Elimination of individuals with certain traits
Reproduction of survivors
Figure 1.6B

22. All organisms have adaptations
All organisms have adaptations
That have evolved by means of natural selection
Killer whale
Pangolin
Figure 1.6C

23. 1.7 Scientists use two main approaches to learn about nature
THE PROCESS OF SCIENCE
1.7 Scientists use two main approaches to learn about nature
Science
Is a way of knowing
Seeks natural causes for natural phenomena

24. Discovery Science In discovery science
Discovery Science
In discovery science
Scientists describe some aspect of the world and use inductive reasoning to draw general conclusions

25. Hypothesis-Based Science
Hypothesis-Based Science
In hypothesis-based science
Scientists attempt to explain obser vations by testing hypotheses

26. 1.8 With hypothesis-based science, we pose and test hypotheses
1.8 With hypothesis-based science, we pose and test hypotheses
Hypothesis-based science involves
Obser vations, questions, hypotheses as tentative answers to questions
Deductions leading to predictions, and then tests of predictions to see if a hypothesis is falsifiable

27. A Case Study from Ever yday Life
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

28. 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

29. BIOLOGY AND EVERYDAY LIFE CONNECTION
1.8 Biology is connected to our lives in many ways

30. 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

31. Many technological advances
Stem from scientific research
The science-technology-society relationship
Is an impor tant aspect of a biology course