1. The Science of Biology Notes
Chapter 1

2. 1-1 What is Science? What science is & is not Goals of Science:
To investigate & understand the natural world
To explain events in natural world
To use explanation to make useful predictions

3. Features of Science:
Deals only with natural world
Scientists collect & organize info in a careful orderly way
Scientists propose explanations that can be tested
Science – an organized way of using evidence to learn about the natural world

4. Thinking like a Scientist
Observation – gathering info about events or processes in a careful orderly way
Uses the senses especially sight & hearing
Produces data – info gathered from observations
Quantitative – expressed as numbers obtained by counting
Qualitative – descriptive & can’t be counted
Used to make inferences – logical interpretations based on previous knowledge

5. Explaining & Interpreting Evidence
Hypothesis – proposed scientific explanation for a set of observations
“testable statement”
Many times is a prediction
Come up with hypothesis by
Prior knowledge
Logical inference
Creative imagination
Must be able to be tested
Use controlled experiments
Gather more data

6. Researchers work in teams Meet regularly Analyze, review & critique one another Helps ensure data is valid

7. Science as a Way of Knowing
Is an ongoing process
Scientists need to be open-minded
Whole physical universe is a collection of parts & processes that interact
Basic laws of nature govern all events & objects
Biologists focus on living systems
Science & Human Values-must work together based on society, morals & laws

8. 1-2 How Scientists Work Designing an experiment
Ask a question – about an observation
Form a hypothesis ex: Redi’s experiment
Set up a controlled experiment
1. Controlled =only 1 variable is tested at a time
2. Variables – factors that can change
ex: type of material used, light, time, etc.
a. Manipulated ( independent) variable-factor that is deliberately changed
b. Responding (dependent) variable-factor that changes in response to the independent factor and is observed.

9. Recording & Analyzing Results
Keep a written record of observations or data
May include drawings, measurements, etc.
Repeating Investigations
1. Nature behaves in a consistent manner
a. 1 variable manipulated in a given set of variables → results should be the same.
b. communication & experiment description is necessary.
2. Scientists publish reports→ others look for flaws & repeatability

10. Some experiments are not possible
Practical & ethical considerations prevent controlled experiments
Alternative investigations
Field study – observe animal interactions
Study large groups
Tries to identify as many relevant variables as possible
How a theory develops
Theory – well tested explanation that unifies a broad range of observations
Uses evidence from numerous investigations
Allows scientists to make accurate predictions about new situations
No theory is absolute; can be revised or replaced

11. 1-3 Studying Life Biology – study of life
Characteristics of Living things:
Are made of cells
Reproduce
Sexual – 2 parents
Asexual- 1 parent
Have universal genetic code
Grow & develop
Have metabolism- obtain & use energy
Respond to their environment
Homeostasis- stable internal environment
Evolution- a species changes over time

12. Big Ideas in Biology (Themes)
Science is a way of knowing
Job of Science – to use observations, questions & experiments to explain the natural world in terms of natural forces & events
Interdependence in Nature
All forms of life are interconnected → flow of energy and cycling of matter
Matter & Energy – life’s most basic requirements
Matter- nutrients to build body structures
Energy- fuel process

13. Cellular basis of Life
Cells – complex & highly organized
Unicellular – one cell
Multicellular- > than one cell
Information & Heredity – DNA is the info; heredity –is passing of info to offspring
Unity & diversity of Life – all life is basically alike at the molecular level; but there are a variety of forms
Evolution- species change over time
Structure & Function: Each structure has certain function. Wing = allows flying
Homeostasis – stable internal environment; allows organisms to adapt to external changes
Science, technology & society: If we have the knowledge & tools, should we always do it?

14. Some Branches of Biology :
Zoology
Botany
Paleontology
Ecology

15. Levels of Organization ( Large to Small)
Biosphere – part of the Earth in which life exists Ecosystem – community + physical environment Community – populations of all species living in the same space Population – group of individuals of the same species living in the same space Organism – individual made of interdependent groups of cells Groups of cells – cells that do specific jobs- tissue Cell – basic unit of life Molecules – smallest unit of most compounds

16. Biology in Everyday & Issues in biology
Helps you understand what affects the quality of your life
Gives you info to make informed decisions

17. Tools & Procedures Common system of measurement
1. needed to replicate experiments accurately
2. metric – decimal system based on multiples of 10
B. Analyzing Biological Data
1. Use tables & graphs
2. Graphs allow patterns to be seen easier
C. Microscopes – device that magnifies images of structures too small to be seen with unaided eye.
1. Light Microscope- most common
uses visible light rays
Compound scope – uses two lenses
Can study dead organisms & tiny alive organisms
Chemical stains (Dyes) can show specific structures

18. Electron
Uses beam of electrons to produce image
studies objects smaller than 0.2µm
~ 1000x more detailed than light microscope
Must be viewed in a vacuum- no living specimens
2 types = TEM & SEM
Lab Techniques – many
1. cell culture – group of cells grown in nutrient solution from a single original cell
2. cell fractionation – separating different cell parts

19. E. Working Safely
1. Before beginning any activity, read all steps.
2. Most important: always follow teacher instructions & textbook directions exactly!