Chapter 1 Exploring Life 1. Define biology 2. Define living 3. Scientific Inquiry 4. Biological...
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Transcript of Chapter 1 Exploring Life 1. Define biology 2. Define living 3. Scientific Inquiry 4. Biological...
Chapter 1Chapter 1
Exploring LifeExploring Life
1. Define biology1. Define biology
2. Define living2. Define living
3. Scientific Inquiry3. Scientific Inquiry
4. Biological Hierarchy4. Biological Hierarchy
5. Biological Themes5. Biological Themes
What is Biology?What is Biology?
Definition Definition
Scientific study of LIFEScientific study of LIFE
What is Living?What is Living?
To be classified as living, these To be classified as living, these criteria must be met:criteria must be met:
1.1. Highly ordered structureHighly ordered structure
2.2. Evolutionary adaptationEvolutionary adaptation
3.3. Respond to environmentRespond to environment
What is living?What is living?
4. Regulation of internal functions4. Regulation of internal functions
* Homeostasis* Homeostasis
5. Process energy5. Process energy
6. Grow & Development6. Grow & Development
7. Reproduce7. Reproduce
* Hereditary Material* Hereditary Material
How is Biology How is Biology Studied?Studied?
Science (“to know”)Science (“to know”)
IncludesIncludes
1. Body of knowledge1. Body of knowledge
2. Scientific Inquiry process2. Scientific Inquiry processSearch for information & explanationSearch for information & explanation
focus on specific questionsfocus on specific questions
Scientific InquiryScientific Inquiry
Two types Two types 1.1. Discovery scienceDiscovery science
Describe natural processesDescribe natural processes
ObservationObservation
Inductive Reasoning (generalizations Inductive Reasoning (generalizations from specific observations)from specific observations)
““All organisms are made of cells”All organisms are made of cells”
Scientific InquiryScientific Inquiry
2. Hypothesis-based science2. Hypothesis-based scienceFocus on explanationsFocus on explanations*Hypothesis*HypothesisDeductive ReasoningDeductive Reasoninggeneral to specificgeneral to specificif ---> thenif ---> then
““if all organisms are made of cells, if all organisms are made of cells, then humans are composed of cells”then humans are composed of cells”
Observations
Questions
Hypothesis # 1:Dead batteries
Hypothesis # 2:Burnt-out bulb
Prediction:Replacing batterieswill fix problem
Prediction:Replacing bulbwill fix problem
Test prediction
Test does not falsify hypothesis
Test prediction
Test falsifies hypothesisFigure 1.25
Hypothesis-Based Hypothesis-Based ScienceScience
Idealized Scientific MethodIdealized Scientific Method
1. Observation1. Observation
2. Question2. Question
3. Hypothesis3. Hypothesis
4. Experiment4. Experiment
5. Conclusion5. Conclusion
Scientific MethodScientific Method
1.1. Must be testableMust be testable
2.2. Must be falsifiableMust be falsifiable
3.3. Experiments must be repeatableExperiments must be repeatable
4.4. Control effects of unwanted Control effects of unwanted variablesvariables
5.5. Supernatural phenomena is not Supernatural phenomena is not addressedaddressed
DataData
Two types of recorded observationsTwo types of recorded observations
1. Quantitative1. Quantitative
2. Qualitative2. Qualitative
Figure 1.24
Hierarchy of BiologyHierarchy of Biology
Levels of OrganizationLevels of Organization
1. Molecules1. Molecules
2. Organelles2. Organelles
subcellular, specific functionssubcellular, specific functions
3. Cells3. Cells
Hierarchy of BiologyHierarchy of Biology
4. Tissues4. Tissues
5. Organs5. Organs
6. Organ System6. Organ System
Hierarchy of BiologyHierarchy of Biology
7.7. OrganismOrganism
8.8. PopulationPopulation
9.9. CommunityCommunity
Cell
8 Cells
6 Organs and organ systems
7 Tissues
10 Molecules
9 Organelles
50 µm
10 µm
1 µm
Atoms
Figure 1.3
Themes of BiologyThemes of Biology
1.1. CellCellBasic unit of lifeBasic unit of life
smallest unit that can perform all smallest unit that can perform all activities of lifeactivities of life
25 µmFigure 1.5
Two Cell TypesTwo Cell Types
1. Prokaryotic1. Prokaryoticno membrane bound nucleusno membrane bound nucleus
no membrane bound organellesno membrane bound organelles
primarily bacteriaprimarily bacteria
Two cell typesTwo cell types
2. Eukaryotic2. Eukaryoticmembrane bound nucleusmembrane bound nucleus
several membrane bound organellesseveral membrane bound organelles
ex. Protists, fungi, plants, animalsex. Protists, fungi, plants, animals
EUKARYOTIC CELL
Membrane
Cytoplasm
Organelles
Nucleus (contains DNA)1 µm
PROKARYOTIC CELL
DNA
(no nucleus)
Membrane
Figure 1.8
Themes of BiologyThemes of Biology
2.2. DNA is heritable informationDNA is heritable informationallows for continuity of allows for continuity of
life by transmitting life by transmitting
biological informationbiological information
DNA
Cell
Nucleotide
ACTA
T
A
CC
G
G
TA
TA
(b) Single strand of DNA. These geometric shapes and letters are simple symbols for the nucleotides in a small section of one chain of a DNA molecule. Genetic information is encoded in specific sequences
of the four types of nucleotides (their names are abbreviated here as A, T, C, and G).
(a) DNA double helix. This model shows
each atom in a segment of DNA.Made up of two long chains of building blocks called nucleotides, a DNA molecule takes the three-dimensional form of a double helix.
Nucleus
Themes of BiologyThemes of Biology
3.3. Emergent propertiesEmergent properties
refers to unique, new property of each refers to unique, new property of each hierarchy level not present at the simpler hierarchy level not present at the simpler
levellevel
Themes of BiologyThemes of Biology
4.4. Feedback RegulationFeedback Regulationkind of supply and demand economykind of supply and demand economy
regulate production of enzymes, proteinsregulate production of enzymes, proteins
Two types:Two types:1. Negative feedback (product turns it off)1. Negative feedback (product turns it off)
2. Positive feedback (product speeds it up)2. Positive feedback (product speeds it up)
Negative FeedbackNegative Feedback
B
A
C
D
Enzyme 1
Enzyme 1
Enzyme 2
Enzyme 3
DD D D
D
D
DD
DD
C
B
A Negative feedback
Figure 1.11
Positive FeedbackPositive Feedback
WW
X
Y
Z
ZZ
ZZ
Z
Z Z Z
Z Z Z Z
Z
ZZ Z
ZZ
Y
X
Enzyme 4
Enzyme 5
Enzyme 6
Enzyme 4
Enzyme 5
Enzyme 6
Positivefeedback
Figure 1.12
Themes of BiologyThemes of Biology
5.5. Interaction with environmentInteraction with environmentinteractionsinteractions
abiotic factorsabiotic factors
biotic factorsbiotic factors
6.6. Energy and lifeEnergy and lifeOrganisms must perform workOrganisms must perform work
Energy flowEnergy flow
Themes of BiologyThemes of Biology
7.7. Unity in the Unity in the
Diversity Diversity
of Lifeof Life Cilia of Paramecium.The cilia of Parameciumpropel the cell throughpond water.
Cross section of cilium, as viewedwith an electron microscope
15 µm
1.0 µm
5 µm
Cilia of windpipe cells. The cells that line the human windpipe are equipped with cilia that help keep the lungs clean by moving a film of debris-trapping mucus upward.Figure 1.16
Paradox of Unity & Paradox of Unity & DiversityDiversity
UnityUnity
1. DNA is the genetic, heritable 1. DNA is the genetic, heritable material, universal genetic material, universal genetic
codecode
2. Universal processes2. Universal processes
Replication, Transcription, Replication, Transcription, TranslationTranslation
Paradox of Unity & Paradox of Unity & DiversityDiversity
DiversityDiversity
vast collection of living organisms vast collection of living organisms on Earthon Earth
categorized into levels based on similaritiescategorized into levels based on similarities
Classifying LifeClassifying Life
Taxonomy – branch of bio that names Taxonomy – branch of bio that names and classifies speciesand classifies species DomainDomainKingdomKingdomPhylumPhylumClassClassOrderOrderFamilyFamilyGenusGenusSpeciesSpecies
Classifying LifeClassifying Life
3 Domains3 Domains1.1. Bacteria - prokaryotesBacteria - prokaryotes
2.2. Archaea - prokaryotesArchaea - prokaryotes
3.3. Eukarya - eukaryotesEukarya - eukaryotes
Figure 1.15
100 µm
0.5 µm
4 µmBacteria are the most diverse and widespread prokaryotes and are now divided among multiple kingdoms. Each of the rod-shapedstructures in this photo is a bacterial cell.
Protists (multiple kingdoms)are unicellular eukaryotes and their relatively simple multicellular relatives.Pictured here is an assortment of protists inhabiting pond water. Scientists are currently debating how to split the protistsinto several kingdoms that better represent evolution and diversity.
Kingdom Plantae consists of multicellula eukaryotes that carry out photosynthesis, the conversion of light energy to food.
Many of the prokaryotes known as archaea live in Earth‘s extreme environments, such as salty lakes and boiling hot springs. Domain Archaea includes multiple kingdoms. The photoshows a colony composed of many cells.
Kindom Fungi is defined in part by thenutritional mode of its members, suchas this mushroom, which absorb nutrientsafter decomposing organic material.
Kindom Animalia consists of multicellular eukaryotes thatingest other organisms.
DOMAIN ARCHAEA
Themes of BiologyThemes of Biology
8.8. Evolution Evolution
accounts for diversity based on life’s accounts for diversity based on life’s unityunity
CharlesCharles
DarwinDarwin
Figure 1.18
EvolutionEvolution
Charles Darwin in Charles Darwin in The Origin of The Origin of Species Species articulated two main articulated two main points:points:
1. Descent with modification1. Descent with modification
2. Natural selection2. Natural selection
Themes of BiologyThemes of Biology
9.9. Structure & Function – Structure & Function – everything everything has purpose at all biological levelshas purpose at all biological levels
10.10. Scientific InquiryScientific Inquiry
11.11. Science, Technology, & Society – Science, Technology, & Society – applications of science & production of applications of science & production of technologies to benefit societytechnologies to benefit society