1. Introduction: Biology Today
CHAPTER 1
Introduction: Biology Today

2. Biology is the scientific study of life.
The Scope of Life
Biology is the scientific study of life.
size scale ranging from the molecular to the global
How do we know what is living?
There are SEVEN characteristics all living things must ALL have:

3. Seven Characteristics of Life
Order: must be organized, certain parts do certain things, cells Regulation: maintain stable internal conditions; homeostasis Growth and Development: get larger and change Energy Utilization: Take energy in and use it; ‘eat’ Response to the Environment: Stimuli Reproduction: Make more of same kind Evolution: Be the best at what it does

4. Figure 1.2

5. Regulation: When it is thirsty it drinks
Example: Dog
Order: has muscle cells that allow it to move
Regulation: When it is thirsty it drinks

6. Energy Utilization: eats then plays
Example: Dog
Growth and Development: Gets larger and changes from a puppy to an adult dog
Energy Utilization: eats then plays

7. Reproduction: PUPPIES
Example: Dog
Responds to the environment: Hides for a thunderstorm, moves into shade when hot
Reproduction: PUPPIES
Evolution:

8. Example: Calculator

9. Example: Calculator
Order: add button does a different thing than the subtract Regulation: does not maintain stable conditions Growth and Development: does not grow or change Energy Utilization: Does take in light energy and use it to calculate Response to the Environment: doesn’t respond Reproduction: does not have sex and make baby calculators, nor does it divide into two new calculators Evolution: has changed over time but not without human help.

10. Life at Its Many Levels
Biologists explore life at levels ranging from the biosphere to the molecules that make up cells.

11. We can distinguish two major types of cells:
The cell is the smallest level of structure that can perform all activities required for life.
All organisms are composed of cells.
We can distinguish two major types of cells:
Prokaryotic
Eukaryotic

12. The prokaryotic cell is simple, small, and contains no organelles.
The eukaryotic cell is larger and more complex and contains organelles.

13. Figure 1.5

14. Life in Its Diverse Forms
Diversity is the hallmark of life.
The diversity of known life includes 1.8 million species.
Estimates of the total diversity range from 10 million to over 200 million species.
Taxonomy is the branch of biology that helps categorize this diversity

15. The Three Domains of Life
The three domains of life are:
Bacteria
Archaea
Eukarya

16. Bacteria and Archaea are both prokaryotic domains.

17. Eukarya includes at least four kingdoms:
Plantae
Fungi
Animalia
Protists (multiple kingdoms)

18. The word science is derived from a Latin verb meaning “to know.”
The Process of Science
The word science is derived from a Latin verb meaning “to know.”
Science is a way of knowing.
Science developed from people’s curiosity about themselves and the world around them.

19. Figure 1.17

20. Hypothesis-Driven Science
As a formal process of inquiry, the scientific method consists of a series of steps.
The key element of the scientific method is hypothesis-driven science.

21. Figure 1.18

22. A hypothesis is a tentative answer to some question.
It is an explanation on trial.

23. Figure 1.19

24. The Process of Science: Can Colors Protect a Snake?
One way to learn more about how hypothesis-based science works is to examine a case study, an in-depth examination of an actual investigation.
Copyright © 2007 Pearson Education Inc., publishing as Pearson Benjamin Cummings

25. Biologists developed a hypothesis regarding mimicry in snakes.
They tested the hypothesis by making artificial snakes and observing how often they were attacked by predators.

26. Figure 1.21

27. This is an example of a controlled experiment.
Such an experiment is designed to compare an experimental group with a control group.
Ideally, a control group and an experimental group differ in only one variable.

28. Scientists build on what has been learned from earlier research.
The Culture of Science
Scientists build on what has been learned from earlier research.
They pay close attention to contemporary scientists working on the same problem.

29. Science, Technology, and Society
Science and technology are interdependent.
New technologies advance science.
Scientific discoveries lead to new technologies.
For example, the discovery of the structure of DNA 50 years ago led to a variety of DNA technologies.

30. Technology has improved our standard of living in many ways, but it is a double-edged sword.
Technology that keeps people healthier has enabled the human population to grow tenfold in the past 300 years.
The environmental consequences of this population growth may be devastating.