1. Introduction
Chapter 1:
Sections 1.1, 1.2, 1.3

2. Characteristics of living things
Complex organized structure
Organic molecules (carbon framework!) are the key molecules that form this structure for Earth’s organisms.
Note the difference between the scientific definition of organic vs. the organic foods movement’s definition!

4. Characteristics of living things
Respond to stimuli from their environment

5. Characteristics of living things
Exhibit homeostasis: Actively maintain a relatively constant internal environment and structure
Example: Humans sweat to cool off and maintain a body temperature of 98.6ºF

6. Characteristics of living things
Acquire and use materials and energy from the environment
Convert to different forms

7. Characteristics of living things
Growth
Reproduction
DNA is the molecule of heredity on Earth

8. Characteristics of living things
Have the capacity to evolve
Change in the genetic composition, and thus the characteristics, of a population over generations.
It is populations, not individuals, that evolve

9. Diversity of life Three domains: Bacteria, Archaea and Eukarya
Domain Eukarya is further divided into Four Kingdoms
Fungi
Plantae
Animalia
Protista

10. Diversity of life Focus: Domains Bacteria & Archaea Single-celled
Relatively simple; no nucleus (prokaryotic)
No membrane-bound structures
Relatively small
Differ from each other structurally and biochemically…

11. Diversity of life Focus: Domain Eukarya
All have nuclei and other membrane-bound organelles
Generally larger than Bacteria and Archaea
We will explore differences among these groups…
Protista
Animalia
Fungi
Plantae

12. What is the science of biology? Or, “Thinking like a scientist”
General scientific principles
All events are traceable to natural causes.
No intervention of “supernatural forces” that do not act consistently with natural laws.
Natural laws apply throughout space and time.
Example: Gravitational laws are the same throughout the universe and throughout time.
People perceive natural events in similar ways.
Allows different people to compare results of their experiments.

13. The scientific method (idealized)
Observations
Hypothesis
Explanation for observed phenomena that is testable, and thus falsifiable.
Leads to one or more predictions that can be tested
Experiments
Controlled observations that test specific predictions
Conclusion
Did the experimental results support the hypothesis?
Did the experimental results disprove the hypothesis?

14. The scientific method (idealized): An example
In the 1600’s, Francesco Redi used the scientific method to challenge the idea that maggots in meat were produced by “spontaneous generation.”
Alternate hypothesis: “Maggots in meat are produced by spontaneous generation.”

16. Conclusions?
Original hypothesis (text): Flies produce maggots; keeping flies away will prevent the appearance of maggots.
Alternate hypothesis: “Maggots in meat are produced by spontaneous generation.”
Did the results support either hypothesis?
Did the results falsify either hypothesis?
Notice the power of falsification!

17. Scientific theories
Like hypotheses, theories are testable and falsifiable!
Theories have been thoroughly tested; much supporting evidence has been found!
Developed via inductive reasoning.
Many specific observations  general theory.