UNIT I – UNITY & DIVERSITY OF LIFE
Hillis – Chp 1, 19, 20 (pgs. 392-406), 22Big Campbell ~ Ch 1, 18, 27, 28, 31Baby Campbell ~ Ch 1, 10, 16, 17
I. EXPERIMENTAL DESIGN, cont• Types of Experiments
o Comparative, Observational, Controlled
• Setting up a Controlled Experimento Clearly defined purposeo Valid, clear hypothesis
Testable statement or predictionDo not use “I think …”, “My hypothesis is …”, etc!Often written in “If …, then …” format but not required
o Control Group Benchmark or standard for comparison
o Experimental or Test Group(s) Only one factor can be changed in each test Independent (Manipulated) VariableDependent (Responding) Variable
I. EXPERIMENTAL DESIGN, cont
• Important Considerationso Controlled variables (aka control variables, constants) must be
monitoredAdditional factors that could change from one set-up to another
o Sample Sizeo Potential sources of erroro Is it repeatable?
• Presentation of Datao Concise & Organized
Tables
I. EXPERIMENTAL DESIGN, conto Graphs
Format Descriptive title Key Units must be evenly spaced (line break) and labeled Use at least half of available space Use a RULER!!!
DRY MIX
Types of Graphs Continuous Independent Variable (time) → _Line_ Graph Discrete Independent Variable → _Bar__ Graph Part of a Whole → ___Pie___ Graph
I. EXPERIMENTAL DESIGN, conto Graphs, cont
For Height Lab …MeanMedianModeRangeHistogram
Normal Distribution?
I. EXPERIMENTAL DESIGN, conto Data Analysis
Null Hypothesis“Statement of No Effect” States that any differences in data sets are due to random errors that
cannot be eliminated in experimental design/protocol For example,
There are no significant differences between predicted and observed data.
There are no significant differences between control group data and test group data.
Alternate Hypothesis – it is formulated to describe the effect that we expect our data to support.
Statistical Analysis – Supports or refutes null hypothesis
I. EXPERIMENTAL DESIGN, contExamine the data below showing two different experiments in which the heart rate of 10 different individuals was measured in beats/minute.
Study A Study B
68 68
70 84
76 90
62 60
70 92
72 58
74 64
67 66
68 78
70 86
I. EXPERIMENTAL DESIGN, contCalculate the standard deviation for each data set.
Study A Study B
68 68
70 84
76 90
62 60
70 92
72 58
74 64
67 66
68 78
70 86
I. EXPERIMENTAL DESIGN, cont• Is there is a significant difference between the average heart
beat/minutes in the two data sets? Construct a graph to illustrate.
I. EXPERIMENTAL DESIGN, cont
• Conclusiono Evaluate hypothesis
Was it supported, refuted, or were results inconclusive?o Assess experimental design
Was there only one independent variable? Were sources of error minimized? Controlled variables/constants Repeatable?
• Theory
II. UNITY OF LIFE
• Form vs. Function
• Characteristics of Life
o All living things are made of
_cells_.
Prokaryotic
Eukaryotic
II. UNITY OF LIFE, cont.• Characteristics of Life, cont
o Living things obtain and use energy.
o Living things respond to their environment.
o Living things grow and develop.
o Living things maintain homeostasis.
o Living things are based on a universal genetic code.
o Living things reproduce.
o As a group, living things evolve.
III. HIERARCHY OF LIFEo Organization of Life
Biosphere Ecosystem Community Population Organism
organ system organ tissue cell
Organelle Molecule Atom
III. HIERARCHY OF LIFE, cont• Classification of Life
Domain
Kingdom Phylum
Class
Order
Family
Genus
Species
III. HIERARCHY OF LIFE, cont
• A Closer Look at Classification Domain _Archaea_
Kingdom __Archaebacteria__
Domain _Bacteria_ Kingdom _Eubacteria__
Domain __Eukarya__ Kingdom _Protista___ Kingdom __Fungi___ Kingdom __Plantae___ Kingdom __Animalia___
IV. CHALLENGING THE BOUNDARIES OF LIFE
• Viruses . . . Living or Non-living? Discovery of Viruses
First isolated by Ivanowsky in 1890s from infected tobacco leaves
Crystallized by Stanley in 1935 – proved viruses were not cells
Not capable of carrying out life processes without a host cell
Parasites
IV. BOUNDARIES, cont• Viruses, cont
Structures found in all viruses: Viral genome
DNA or RNA.May be single-stranded or double-stranded
Protein coat Known as a capsid Made up of protein subunits called
capsomeres.
IV. BOUNDARIES, cont
• Viruses, cont Structures/adaptations that may be present:
Viral envelope Typically derived from host cell membrane
o Exception is Herpes virus, synthesized from nuclear envelope of host cell
Aid in attachment. Envelope glycoproteins bind to receptor molecules on host cell
Most viruses that infect animals have envelope Tail – Found in some viruses to aid in attachment
IV. BOUNDARIES, cont
• Viruses, cont. Bacteriophage
Infect bacteria Bacterial Defense Mechanisms
Restriction Enzymes
Coexistence
IV. BOUNDARIES, cont – Viral Replication1. Virus enters; is uncoated; releases viral genome and capsid proteins
2. Host enzymes replicate the viral genome
3. Host enzymes replicate viral genome
4. Viral genomes and capsids self-assemble into new viral particles; exit the cell
IV. BOUNDARIES, cont – Viral Replication
1. Lytic Cycle – Results in death of host cell.
LYTIC CYCLE
IV. BOUNDARIES, cont – Human Viruses
• DNA Viruseso No envelope
Papilloma Virus Warts, cervical cancer
o With envelopeSmallpox Virus - cowpoxHerpesvirus
Herpes simplex I and II – cold sores, genital sores
Epstein-Barr virus – mono, burkitt’s lymphoma
Varicella zoster – shingles, chicken pox
IV. BOUNDARIES, cont – Human Viruses
• RNA Viruseso No envelope
Rhinovirus – common coldo Envelope
Coronavirus - SARSFilovirus – Ebola (hemmorrhagic fever)Influenza virus - fluHIV
Belongs to a group of viruses known as _Retroviruses__ Contain RNA, reverse transcriptase
Converts _RNA_ to _DNA_
IV. BOUNDARIES, cont – HIV
A Closer Look at Human Immunodeficiency Virus Infects WBCs known as Helper T
cells Can reside in lysogenic-like cycle
for years Active, symptomatic = AIDS
IV. BOUNDARIES, cont• Viroids
o Single, circular RNA molecule; lack proteino Parasitize plants
• Prionso Infectious proteins; lack nucleic acido Cause Mad Cow Disease, Creutzfeldt-Jakob Diseaseo Very long incubation periodo No treatment
V. THE DIVERSITY OF LIFEKingdom Type of Cell Cell Structures Nutrition Description
Archaebacteria • •
Cell wall not made of _____________
Mostly _______________
“______________ bacteria”; require ______ conditions
Eubacteria • •
Cell wall made of _______________
Mostly _______________
Ubiquitous; __________; may be pathogenic
Protista • •Mostly ________
May have cell wall, chloroplasts, flagella
Auto or hetero “_______________________”; very diverse “kingdom”
Fungi • •Mostly ________
Cell wall made of ____________; no ______________!
Strictly _______________ (______________)
All non-motile; _______________
Plantae • •
Cell wall made of ____________; all have chloroplasts
Strictly _______________(______________)
All non-motile
Animalia • •
Never have _____ ____________; chloroplasts
Strictly _______________(______________)
All ___________ during life cycle; most complex
IV. THE DIVERSITY OF LIFEKingdom Type of Cell Cell Structures Nutrition Description
Archaebacteria •Prokaryotic•Unicellular
Cell wall not made of peptidoglycan
Mostly heterotrophic
“Ancient bacteria”; require harsh conditions
Eubacteria •Prokaryotic•Unicellular
Cell wall made of peptidoglycan
Mostly heterotrophic
Ubiquitous; decomposers; may be pathogenic
Protista •Eukaryotic•Mostly uni
May have cell wall, chloroplasts, flagella
Auto or hetero “Junk Drawer of Life”; very diverse “kingdom”
Fungi •Eukaryotic•Mostly multi
Cell wall made of chitin; no chloroplasts!
Strictly heterotrophic (absorption)
All non-motile; decomposers
Plantae •Eukaryotic•Multicellular
Cell wall made of cellulose; all have chloroplasts
Strictly autotrophic(photosynthesis)
All non-motile
Animalia •Eukaryotic•Multicellular
Never have cell walls or chloroplasts
Strictly heterotrophic(ingestion)
All motile during life cycle
VI. PROKARYOTES – A CLOSER LOOK
VI. PROKARYOTES, cont• Archaebacteria
Examples include methanogens, thermoacidophiles, halophiles Taq DNA polymerase
VI. PROKARYOTES, contEubacteria
Ubiquitous May be pathogenic Most are harmless
• Classification Shape
Cocci Bacilli Spirilla
Gram Stain Reaction Positive
Negative
VI. PROKARYOTES – EUBACTERIA, cont
• Nucleoid region • Plasmids• Asexual reproduction
Binary fission
VI. PROKARYOTES – EUBACTERIA, cont
• Adaptations Capsule
Adherence Protection Associated with
virulence Pili
Adherence Conjugation
Endospore Bacterial
“hibernation” Motility
(flagella, slime,
Spore formation – adaptation seen in some bacteria that allows them to survive adverse conditions. A hard, protective wall forms around the DNA of the bacteria – and the bacteria can survive for centuries. When favorable conditions return, the spores revive, and the bacteria is able to revive and germinate. Ex. Bacillus anthracis; Clostridium botulinum
Bacillus anthracis
VI. PROKARYOTES – EUBACTERIA, cont
• Adaptations, cont Quorum Sensing/Biofilms
Fairly recent discovery Bacteria exchange chemical
communication signals Multicellularity???
“Sexual Reproduction” Genetic Recombination
Occurs by: Transformation Transduction Conjugation
• Transduction – transfer of genes between a bacteria and a virus vector – the virus inserts new genes into the bacteria…. This method is used in biotechnology to create bacteria that produce valuable products such as insulin.
• Conjugation – a form of sexual reproduction in which there is a direct transfer of a plasmid from one bacteria to another (through pili) before the bacteria divides – results in offspring with new genes/traits.
- Plasmid - smaller ring of DNA that functions in antibiotic resistance or metabolism; replicates independently of the entire DNA
VI. PROKARYOTES – EUBACTERIA, cont
• Metabolismo Nitrogen fixation
Conversion of atmospheric nitrogen (N2) to ammonium (NH4
+)
o Metabolic CooperationBiofilms
o Oxygen relationshipsObligate aerobes
Facultative anaerobes
Obligate anaerobes
VI. PROKARYOTES – EUBACTERIA, contBacterial Pathogenesis• Koch’s Postulates – Criteria for bacterial disease confirmation
The microorganism is found in all individuals with the disease. The microorganism can be cultured from the host. The isolated organism will produce disease when injected into another host. The organism can be isolated from the newly infected host.
• “Normal Flora”• Some bacteria are opportunistic pathogens
Normal residents of host; cause illness when defenses are weakened
• Toxin Production Exotoxins - Bacterial proteins that can produce disease w/o the prokaryote
present (botulism, cholera) Endotoxins - Components of gram negative membranes (typhoid fever,
Salmonella food poisoning)
VI. PROKARYOTES – EUBACTERIA, cont
• Bacterial Pathogenesis, cont Examples
Clostridium sp.
Staphylococcus
Streptococcus
Neisseria sp.
Mycobacterium tuberculosis
Legionella pneumophila
VII. KINGDOM PROTISTA• Very diverse• All _Eukaryotic_• Mostly _Heterotrophic_• Classified according to eukaryotic kingdom
protist is most like, nutrition Animal-like
Ingestive Protozoans
Plant-like Photosynthetic Algae, kelp, seaweed Very impt aquatic producers;
phytoplankton Fungus-like
Absorptive Slime Molds
VII. KINGDOM PROTISTA, cont• Important Protozoans
Zooplankton Important component of aquatic food
chains Human Pathogens
Entamoeba o Intestinal pathogeno Associated with dirty, stagnant watero Moves, feeds using pseudopods
Giardia o Lack mitochondria, cell wallso Live in fresh water; flagellatedo Intestinal pathogens
VII. KINGDOM PROTISTA, cont
• Important Protozoans, cont Plasmodium
Belong to Apicomplexa All parasitic, non-motile
Cause malaria Vector = Anopheles mosquito Resistance seen in _________ _Individuals heterozygous for
sickle cell anemia_Toxoplasma
VIII. KINGDOM FUNGI, cont• Absorptive heterotrophs; release
exoenzymes Decomposers (saprobes) Parasites Mutualistic symbionts (lichens)
• Primarily reproduce asexually • Classified according to reproductive
structures• Include mushrooms, bracket fungi,
puffballs• Yeast
Unicellular Reproduce asexually; budding May be pathogenic