Biology Notes/Chapter 1-THE NATURE of LIFE

Biology Notes/Chapter 1-THE NATURE of LIFE

Biology Notes/Chapter 1-THE NATURE OF LIFE

I.What is Science?

A. The goal of science is to investigate and understand the natural world,to explain the events in the natural world ,and to use those explanations to make useful predictions.

  1. deals only w/ natural world
  2. uses systematic way of collecting info--______-looking for patterns and connections
  3. ______-propose explanations that can be tested.
  4. Always changing /open to testing and revisions/continues to advance
  5. Is a way of knowing by gathering and analyzing info
  6. Is a PROCESS–based on evidence and not belief

B. SCIENTIFIC METHODOLOGY/thinking scientifically:

  • Arthur Schropenhauer:”Thinking something that nobody has thought,while looking at something everybody else sees”

1.Usually begin scientific thought w/ an ______-gathering info about events or processing in careful , orderly way-using senses

  • ______-info gathered from observations…..2 Types:

***______-expressed by numbers by counting or measuring…..eg. # times/minute a heart beats or the height of plants in cm.

***______-descriptive and involves that which can’t be counted…..eg.the color of a solution,the saltiness of a potato chip

2.______-logical interpretation based on prior knowledge or experience(based on what you already know)….eg.If the bacterial count in water collected a few places on the Potomac @ Fairview Beach is high w/ infectious forms ,you can infer that all the water in that area is contaminated.

---How Scientists Work-

  • Our ideas and knowledge has evolved greatly---From Aristotle(2300 years ago),when living things were thought to be able to be produced from nonliving--______....to 400 years ago when experimental science actually began.

3.Designing a Controlled Experiment-All variables are kept the same-except one-All that remain the same are ______If not,you will not know what caused your results

  1. Ask a ______.
  2. Form a hypothesis:examples__If______,then______(insert your own hypothesis here)----Scientific explanation for a set of observations that can be tested to support or reject it.

Redi made the hypothesis that flies produce maggots and set up his experiment as follows:

Set up Controlled Experiment

  • ______-factors that change
  • 1 variable @ a time to avoid confusion
  • Variable deliberately changed is called ______variable or IV-______
  • Variable observed and it changes in response to IV-Responding variable –DV-______-usually a measured quantity
  • ______is kept the same/except w/o IV/This is the baseline measurement or normal situation/This is VITAL for comparison/provides reliability to results
  • Record and Analyze Data-typically data table that translates into graph

****Research Tools-must choose appropriate tools and measurement devices,etc.

*****SOURCES OF ERROR-must consider possible error in design and analysis…In medical studies the experimental and control groups are large!

  • Draw conclusion –Is the hypothesis supported or not?

B.Publish & report Investigations

  • Scientists read about and test one another’s results

What did Needham do differently than Redi? ______

What did Spallanzi do differently than Needham? ______

Pasteur

What did Pasteur do differently and what did he prove?______-BIOGENESIS_Life from Life-opposite of spontaneous generation

C. When are experiments not possible?______-Sometimes FIELD STUDIES instead of a lab are needed as w/ animal behavior

D. How a Theory Develops---Results if hypothesis is continually supported and evidence builds up over a period of time……NOT an absolute truth!(MAY BE REVISED OR REPLACED)...In other conversations,theory may mean something different-like an idea-****In science,Theory applies to a WELL TESTED explanation that unifies a broad range of observations and hypotheses that allow scientists to make accurate predictions about new situations-Example-Evolutionary Theory…

II. Science in Context

  1. Where do questions and observations in science come from:
  2. Scientific Attitude-lead to exploration and discovery
  • Skepticism-______
  • Open-mindedness
  • Creativity

2.Practical Problems-example-protecting saltmarshes since the rest of the environment is impacted

3. Role of Technology-Scientific discovery may yield technology and Technology may yield technology

B. Communicating Results

  1. Peer review-publish articles in scientific journals-allows analysis and evaluation
  2. Sharing Knowledge and New Ideas-may lead to a new hypothesis

C.Science and Society-Using science involves its context in society and limitations

1. Pure Science,Ethics,and Morals-science does not include these viewpoints but must be sensitive to them

2. Avoid Bias-a preference or point of view that is personal,rather than scientific

3. Understanding and Using Science-involves continual changing

III.Studying Life-

______=study of life

A.Characteristics of Living Things(8 things !)

  1. made up of ______-living matter enclosed by a barrier-smallest unit considered alive
  2. ______-consists of only 1 cell…like paramecium
  3. ______made of more than 1 cell
  4. Reproduction-sexually(2 parents) or asexually (1 parent)
  5. ______-carries direction for heredity…There is an universal Genetic Code.
  6. Growth and Development
  7. Material use and Energy production-______=combination of chemical reactions through which an organism builds or breaks down materials
  8. Response-to environment

______-signal to which an organism responds

  1. Maintain Internal Balance-HOMEOSTASIS
  2. Evolution-as a group-chage over time
  1. Levels of Organization:
  2. Molecular –more than I atom—C6H12O6
  3. Cellular
  4. Tissues-group of cells w/ particular function
  5. ______-group of tissues that work together to perform closely related function
  6. ______-group of organs that work together w/ a particular function
  7. Population-group of organisms of one type in a particular area
  8. ______-populations that work together in a defined area
  9. ______-community and nonliving surroundings
  10. Biosphere-Part of earth that contains all ecosystems
  1. Fields/Branches of Biology
  2. ______-study animals
  3. ______study plants
  4. ______study ancient life
  5. Molecular and Cell Biologists study @ the small level
  6. Ecologists study the large units
  7. Big Ideas in Biology-interlocking central themes
  8. Cellular Basis for Life-unicelluar/multicellular-more complex
  9. Info and Heredity-DNA provides a universal genetic code
  10. Matter and Energy-interdependent-use materials to produce energy
  11. Growth,Development,and Reproduction
  12. Homeostasis
  13. Evolution
  14. Structure and Function-related
  15. Unity and Diversity-fundamental @ molecular level,but diverse in many ways
  16. Interdependence_ all connected w/in biosphere
  17. Science as a way of knowing-provides tools to learn more
  1. Tools & Procedures

A.______used when collecting data and performing experiments…base 10 system…revised version called SI-International System of Units….******see p. 24 for basic units and abbreviations

B. Analyzing Bio Data

  1. tables

animal / Respiration rate indoors / Respiration rate outdoors
cat / 15 breaths/min. / 17 breaths/min.
bird / 20 breaths/min. / 22 breaths/min.
  1. convert tables to graphs
  1. computers
  1. Microscopes-produce magnified images of structures that are too small to see

1)______-produces images by focusing visible light---up to 1000x….Compound Light Microscope-light passes through image and uses 2 lenses/stains and dyes help highlight what is on slide

2)______-magnifies by focusing beams of electrons/helps w/ images smaller than .2 micrometers/1000x more detailed than light version

  • TEMs-______-shine beam electrons through specimen
  • SEM-______scan narrow beam back and forth across surface of a specimen-often 3-D images

TEM SEM

  1. Lab Techniques-

1)______-cell put in dish w/ nutrient solution/able to reproduce---tested for responses and interactions

2)______-separate different cell parts as in centrifuge-quickly spins and more dense parts @ bottom.

centrifuged blood in hematocrit tube

E. Lab safety-see contract and end of ch 1

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