1. Ch 1: Introduction to Biology

2. Biology – the study of life
Studies origins and history of life and once-living things
Studies structures of living things
Studies how living things interact with each other
Study how living things function

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What do biologists do?
Study diversity of life
Research disease
Develop technologies
Improve agriculture
Preserve the environment
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4. Characteristics of Life
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5. Organism – anything that has ALL the characteristic of life
Made of one or more cells (basic unit of structure and function)
Displays organization (cell-tissues-organs-organ system-organism)
Grows and develops (growth = increase in mass; development = changes that take place during the organisms life)

6. 4. Reproduces (essential for the survival of a species)
5. Responds to stimuli
6. Requires energy (made themselves or consumed)
7. Maintains homeostasis (regulation of internal conditions)
8. Adaptations evolve over time (inherited characteristics which result in changes to a species)

7. The Nature of Science What is science? Scientists
Body of knowledge based on the study of nature (observation)
Scientists
Make observations and draw conclusions
Expand knowledge through reevaluation of current theories
Challenge accepted theories
Test claims
Undergo peer review (experimental results are evaluated by other scientists in the field)

8. The Nature of Science Theory vs. Law Ethics Psuedoscience
Theory – explanation of a natural phenomenon supported by many observations and experiments over time.
Law – explains relationships under certain condition in nature, but doesn’t have to explain why (gravity)
Ethics
Morals and values held by humans
Ethical issues must be addressed by society based on the values it holds important
Psuedoscience
Questionable or fraudulent science - astrology

9. Scientific Method Ask a Question Form a hypothesis
Scientific inquiry begins with observation which leads to making inferences (combining what you know with what you have learned to make a conclusion)
Form a hypothesis
A testable explanation of a situation

10. Scientific Method Experiment Control group – group used for comparison
Experimental group – group exposed to the factor being tested
Independent variable – only one factor can change at a time; factor being tested
Dependent variable – results from or depends on changes to the independent variable.

11. Scientific Method Collect Data
Data – information gathered from observations
Quantitative data – NUMERICAL – measurements of time, temp., length, mass, area, volume, etc.
Qualitative data – WORDS – descriptions of what our senses detect

12. Scientific Method
Metric System: system of measurement which uses units with divisions that are powers of ten
SI units of measure:
Length – meter
Mass – gram
Volume – liter
Time – seconds
SI (International System of Measurement) are commonly used in science for consistency and ease of communication.
Metric prefixes:
Kilo – 1000
Deci – tenths 1/10
Centi – hundreths 1/100
Milli-thousanths 1/1000

13. Scientific Method Analyze Data Report Conclusions
Graph of the data makes the pattern easier to grasp
Report Conclusions
The conclusion compares the data with the hypothesis