UNIT I – UNITY & DIVERSITY OF LIFE

Big Campbell ~ Ch 1, 18, 27, 28, 31Baby Campbell ~ Ch 1, 10, 16, 17

Biology is . . .

I. “THE STUDY OF . . . “ – EXPERIMENTAL DESIGN

Inquiry-based

I. EXPERIMENTAL DESIGN, cont• Types of Experiments

o Comparativeo Observationalo Controlled

• Setting up a Controlled Experimento 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• Setting up a Controlled Experiment, cont

o Controlled variables (aka control variables, constants) must be monitoredAdditional factors that could change from one set-up to another

o Sample Sizeo Minimize potential sources of erroro Importance of Repeatable Results

• Presentation of Datao Concise & Organized

Tableso Graphs

Descriptive titleKey Units must be evenly spaced (line break) and labeledUse at least half of available space

I. EXPERIMENTAL DESIGN, conto Graphs, cont

DRY MIX

Continuous Independent Variable (time) → _Line_ GraphDiscrete Independent Variable → _Bar__ GraphPart of a Whole → ___Pie___ Graph

o Data AnalysisNull Hypothesis

Statement of “No Effect”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.

Null Hypothesis cont.

• For example: one may want to compare the test scores of two random samples of men and women, and ask whether or not one population has a mean score different from the other.

• A null hypothesis would be that the mean score of the male population was the same as the mean score of the female population.

• http://www.null-hypothesis.co.uk/science//item/what_is_a_null_hypothesis

I. EXPERIMENTAL DESIGN, contStatistical Analysis – Supports or refutes null hypothesis

T Test, ANOVA Chi Square Analysis

statistical hypothesis test; most widely used Measures variation of test results from expected results

to determine if differences are significant Degrees of freedom

# of categories you have in your analysis minus 1.

Acceptable Probability ˃ __.05 or 5%______ Null hypothesis is accepted This means, the probability that the differences

observed are insignificant; that is, due to normal variation are __greater_ than _5_%. In other words, the two data sets can be considered “the same”.

If calculated probability is ≤ 0.05, null hypothesis is rejected; differences are significant.

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 Characteristics

Viral genome may be either single-stranded or double-stranded DNA or RNA.

Protein coat surrounding virus is known as a capsid made up of protein subunits called capsomeres.

Some viruses are also surrounded by a viral envelope Typically derived from host cell membraneException is Herpes virus, synthesized from

nuclear envelope of host cellAid in attachment. Envelope glycoproteins bind to

receptor molecules on host cellMost viruses that infect animals have envelope

Tail – Found in some viruses to aid in attachment

IV. BOUNDARIES, cont

IV. BOUNDARIES, cont

• Viruses, cont. Bacteriophage

Infect bacteria Bacterial Defense Mechanisms

Restriction Enzymes

Coexistence

IV. BOUNDARIES, cont – Viral Replication

IV. BOUNDARIES, cont – Viral Replication

Viral Entrance into Host Cell

IV. BOUNDARIES, cont – Viral Replication

1. Lytic Cycle – Results in death of host cell.

LYTIC CYCLE

IV. BOUNDARIES, cont – Viral ReplicationLYSOGENIC CYCLE

IV. BOUNDARIES, cont – Human Viruses

• DNA Viruseso No envelope

Papilloma Virus

o With envelopeSmallpox VirusHerpesvirus

Herpes simplex I and II

Epstein-Barr virus

Varicella zoster

IV. BOUNDARIES, cont – Human Viruses

• RNA Viruseso No envelope

Rhinoviruso Envelope

CoronavirusFilovirusInfluenza virusHIV

Belongs to a group of viruses known as _Retroviruses__ Contain RNA, reverse transcriptase

Converts _RNA_ to _DNA_

IV. BOUNDARIES, cont – HIV

Human Immunodeficiency VirusInfects WBCs known as Helper T CellsCan reside in lysogenic cycle for yearsActive, 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

Require __Sulfur____________________________ Examples include methanogens, thermoacidophiles, halophiles Taq DNA polymerase

VI. PROKARYOTES, contEubacteria

Ubiquitous May be pathogenic

• 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”

VI. PROKARYOTES – EUBACTERIA, cont

• Adaptations, cont Quorum Sensing/Biofilms

Fairly recent discovery Bacteria exchange chemical

communication signals Multicellularity???

“Sexual Reproduction”

Transformation

Transduction

Conjugation

VI. PROKARYOTES – EUBACTERIA, cont• Adaptations, cont

Motility Flagella

Helical shape Spirochetes

Slime

Taxis

VI. PROKARYOTES – EUBACTERIA, contNutrition• Photoautotrophs

Photosynthetic Harness light to drive the synthesis of

organics Cyanobacteria

• Chemoautotrophs Oxidation of inorganics for energy Obtain carbon from CO2

• Photoheterotrophs Use light to generate ATP Must obtain carbon in an organic form

• Chemoheterotrophs Consume organic molecules for both

energy and carbon Saprobes - decomposers

Parasites

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, cont

Prokaryotic Ecology• Decomposers

• Nitrogen Fixation

• Symbiosis Commensalism

Mutualism

Parasitism

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.

• Opportunistic Normal residents of host; cause illness when defenses are weakened

• Exotoxins Bacterial proteins that can produce disease w/o the prokaryote present

(botulism)

• Endotoxins Components of gram negative membranes (Salmonella)

EUKARYOTES

VII. KINGDOM PROTISTA• Very diverse• All _Eukaryotic_• Mostly _Heterotrophic_• Classified according to eukaryotic

kingdom protist is most like, nutrition Animal-like

Ingestive Protozoa

Plant-like Photosynthetic Algae

Fungus-like Absorptive Slime Molds

VII. KINGDOM PROTISTA, cont

Protist Phylogeny . . . For now!

VII. KINGDOM PROTISTA, cont• Important Protozoans

Zooplankton Important component of aquatic food

chains Euglena

o Protozoan or Algae??o Autotrophic/heterotrophico Pellicle

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 Trypanosoma

Tse-tse fly vector Blood pathogen; flagellated Causes sleeping sickness

Plasmodium Belong to Apicomplexa

All parasitic, non-motile Cause malaria Vector = Anopheles mosquito Resistance seen in _________ _Individuals heterozygous for

sickle cell anemia_

VII. KINGDOM PROTISTA, cont

• Algae Very important aquatic producers Phytoplankton Dinoflagellates

Red Tides Diatoms

Make up most of Earth’s phytoplankton Have glass-like silicon shells

Brown Algae Kelp

Rhodophyta Red Algae Seaweed Also found in coral reefs

VII. KINGDOM PROTISTA, cont

• Algae, cont Chlorophyta

Green AlgaeVolvoxSpirogyraChlamydomonas

Unicellular; may be colonial Chloroplasts, cell walls of cellulose Gave rise to land plants

VII. KINGDOM PROTISTA, cont

• Slime Molds

VIII. KINGDOM FUNGI

VIII. KINGDOM FUNGI, cont

• Absorptive heterotrophs; release exoenzymes Decomposers (saprobes) Parasites Mutualistic symbionts (lichens)

• Cell Walls Made of chitin_

• Hyphae Body filaments Network of hyphae known as a

mycelium

• Primarily reproduce asexually • Classified according to

reproductive structures

VIII. KINGDOM FUNGI, cont

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are needed to see this picture.

Life Cycle

VIII. KINGDOM FUNGI, cont• Important Fungi

Rhizopus Food mold

Mushrooms, puffballs, bracket fungi

Yeast Unicellular Reproduce asexually; budding May be pathogenic

VIII. KINGDOM FUNGI, cont

• Specialized Fungi Molds

Used to be classified as Deuteromycota or “Imperfect Fungi”

No known sexual stage Penicillium

Lichens Mutualistic relationship with algae,

cyanobacterium Sensitive to air pollution

Mycorrhizae Mutualistic relationship found in 95% of all

plants Increases absorptive surface of roots