1. Concepts & Methods in Biology
Chapter 1

2. Why Study Biology?
To learn how organisms are constructed, how they function, where they live, and what they do
To help develop, modify, and refine ideas about life
To understand issues of scientific research

3. Inductive Logic
Using observations and facts to arrive at generalizations or hypotheses
Observation: Eagles, swallows, and robins have feathers
Hypothesis: All birds have feathers

4. Deductive Logic
Drawing a specific conclusion based on a generalization
Generalization - Birds have feathers
Example - Eagles are birds
Conclusion - Eagles have feathers

5. Scientific Method Science is a Process
Observation
Research
Question
Hypothesis – Needs to be testable
Experiment
Results
Conclusion

7. Role of Experiments Used to study a phenomenon under known conditions
Allows you to predict what will happen as long as the hypothesis is not wrong

8. Experimental Design Control group Sampling error
A standard for comparison
Identical to experimental group except for variable being studied
Sampling error
Nonrepresentative sample skews results
Minimize by using large samples

9. Scientific Theory
A hypothesis that has been tested for its predictive power many times and has not yet been found incorrect

10. Theory Vs. Scientific Law
Theory is a hypothesis that has been supported by many lines of evidence
A law is a theory that has been supported for a significant amount of time
Can a theory ever be proven 100% correct?

11. Limits of Science
Scientific approach cannot provide answers to subjective questions
Cannot provide moral, aesthetic, or philosophical standards
Can conflict with supernatural beliefs

12. What is Life? Organization Reproduction – life comes from life
Growth and Development
Metabolism
Response to stimuli
Homeostasis
Adaptation

13. Hierarchy of Life Atoms – C,H,O,N = 96% of the dry weight
Molecules – major organic compounds
Cells – 2 cell types
Tissues
Organs
Organ systems
Organism
Ecological order – population, community, ecosystem

15. Molecules of Life All things are made up of the same units of matter
Living things are made up of a certain subset of molecules:
Nucleic acids
Proteins
Carbohydrates
Lipids

16. DNA (Deoxyribonucleic acid)
Signature molecule of life
Molecule of inheritance
Directs assembly of amino acids

17. DNA Guides Development
Multicelled organisms develop
Instructions for each stage of development is in DNA

18. Nothing Lives without Energy
Energy = Capacity to do work
Metabolism = Reactions by which cells acquire and use energy to grow, survive, and reproduce
Photosynthesis and Cellular Respiration

19. Sensing and Responding
Organisms sense changes in their environment and make responses to them
Receptors detect specific forms of energy (stimuli)
Allows maintenance of :
Homeostasis

20. Interdependencies among Organisms
Producers –
Autotrophs
Make their own food
Consumers –
Heterotrophs
Depend on energy stored in tissues of producers
Decomposers
Break down remains and wastes

21. Energy Flow Usually starts with energy from The Sun
Transfered from one organism to another
Energy flows in one direction
Eventually, all energy flows back to the environment

22. Consumers, Decomposers
ENERGY FROM SUN
Producers
NUTRIENT CYCLING
Consumers, Decomposers
ONE-WAY FLOW OF ENERGY
In time, all energy flows back to the environment.

23. Unity of Life All organisms: Are composed of the same substances
Engage in metabolism
Sense and respond to the environment
Have the capacity to reproduce based on instructions in DNA

24. Diversity of Life Millions of living species Millions more now extinct
Classification schemes attempt to organize diversity

26. Scientific Names Devised by: Binomial Nomenclature
Carolus Linnaeus
Binomial Nomenclature
First name is genus (Capitalized)
Homo sapiens - genus is Homo
Second name is species within genus (Lower case)
Always written either in italics or underlines

27. 3 Domains Eubacteria (Bacteria) Archaebacteria (Archaea) Eukaryota
(Eukaryotes)

28. 6 Kingdoms Protistans Plants Fungi Animals Eukaryotes Archaebacteria
Eubacteria
Origin of life

29. Prokaryotic Organisms
Eukaryotic Organisms
Single- or multi-celled
Nucleus and other organelles
Larger, more complex
Single cells
No nucleus or membrane bound organelles
Smaller, less complex

30. Mutation: Source of Variation
a change in the structure of DNA
Basis for the variation in heritable traits
Most are harmful, beneficial ones may lead to evolution
Point, Frameshift, and Chromosomal

31. Adaptive Trait
A trait that gives the individual an advantage in survival or reproduction, under a given set of circumstances

32. Evolution
Decent with modification
Population changes, not individuals

33. Artificial Selection Breeders are selective agents
Individuals exhibiting favored traits are bred
Favored traits become more common in population

35. Natural Selection Individuals vary in some heritable traits
Some forms of heritable traits are more adaptive
Natural selection is differences in survival and reproduction among individuals that vary in their traits
Adaptive forms of traits become more common than other forms

36. Antibiotic Resistance
Antibiotics are used to kill bacteria
Mutations for antibiotic resistance exist or arise
Antibiotic-resistant bacteria survive and reproduce better than nonresistant
Over time, proportion of antibiotic-resistant bacteria increases