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

Biology is . . .

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

Inquiry-based

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, cont Standard Deviation

I. EXPERIMENTAL DESIGN, contStandard Error of the Mean

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

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

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 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 Viruses

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 – HIV, cont

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

Gram +

Streptococcus pneumoniae

Gram -

Neisseria gonorrhoeae – gram negative; coccus shaped

E.coli – gram negative; rod-shaped

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

Transformation – external DNA incorporated into cells – can come from dead bacteria

• 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

EUKARYOTES

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

Protist Phylogeny . . . For now!

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

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

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 or cyanobacterium Sensitive to air pollution

Mycorrhizae Mutualistic relationship found in

95% of all plants