UNIT I – UNITY & DIVERSITY OF LIFE

Hillis ~ Ch 1, 19, 20, 22Big Campbell ~ Ch 1, 19, 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 a requirement

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) → ____________ GraphDiscrete Independent Variable → _________________ GraphPart of a Whole → _________________ Graph

I. EXPERIMENTAL DESIGN, conto Graphs, cont

For Height Lab …MeanMedianModeRangeHistogram

Normal Distribution?

I. EXPERIMENTAL DESIGN, cont

• Normal Distribution o Bell Curveo Standard Deviation

I. EXPERIMENTAL DESIGN, conto Data Analysis

Null 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.

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

T Test Allows for comparison of the means between 2 data sets In other words, is there a significance difference in the means

or can they be considered the same? Most often used to analyze continuous data

Chi Square Analysis Measures variation of observed test results from expected

results to determine if differences are significant Most often used for categorical data

I. EXPERIMENTAL DESIGN, contChi Square Analysis

• Use the Chi Square formula to find the sum of the variation in the data. This value is Chi Square.

• The Chi Square value is then compared to the critical value in the Probability Table for 0.05 with the correct degrees of freedom. By convention, this is the accepted probability value in science.

• Degrees of freedom = n – 1 where n represents # categories, possible outcomes

I. EXPERIMENTAL DESIGN, contChi Square Analysis

If the Chi Square value is less than the value listed under 0.05, the null hypothesis is accepted. Interpretation → The probability that the differences are due to chance is

greater than 0.05; therefore the differences between the data are considered random and statistically insignificant.

If the Chi Square value is equal to or greater than the value listed, the null hypothesis is rejected. Interpretation → The probability that the differences are due to chance is less

than or equal to 0.05; therefore the differences between the data are statistically significant and cannot be considered due to random error.

I. EXPERIMENTAL DESIGN, cont• A poker-dealing machine is supposed to deal cards at random, as if from

an infinite deck. In a test, you counted 1600 cards and observed the following:o Spades = 404o Hearts = 420o Diamonds = 400o Clubs = 376

• Is the machine dealing randomly?

• Null Hypothesis:

• Chi Square Formula:

• Expected =

I. EXPERIMENTAL DESIGN, cont

I. EXPERIMENTAL DESIGN, cont

• Chi Square =

• Degrees of Freedom =

• P Value

• Interpretation:

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

____________.

II. UNITY OF LIFE, cont.• Characteristics of Life, cont

o

o

o

o

o

o

o

III. HIERARCHY OF LIFEo Organization of Life

III. HIERARCHY OF LIFE, cont• Classification of Life

III. HIERARCHY OF LIFE, cont

• A Closer Look at Classification Domain ________________

Kingdom ________________________

Domain ________________ Kingdom ________________________

Domain ___________________ Kingdom ________________________ Kingdom ________________________ Kingdom ________________________ Kingdom ________________________

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.

Structures/adaptations that may be present: Viral envelope

Typically derived from host cell membraneo Exception 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 Viruses

o No envelope Papilloma Virus

o With envelope Smallpox Virus

Herpesvirus Herpes simplex I and II

Epstein-Barr virus

Varicella zoster

IV. BOUNDARIES, cont – Human Viruses• RNA Viruses

o No envelope Rhinovirus

o Envelope Coronavirus

Influenza virus

Filovirus

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

Converts ________ to __________

IV. BOUNDARIES, cont – HIV

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

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 _________________

• 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

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• Metabolism

o Nitrogen fixationConversion of atmospheric

nitrogen (N2) to ammonium (NH4+)

o Metabolic CooperationBiofilms

o Oxygen relationshipsObligate aerobes

Facultative anaerobes

Obligate anaerobes

VI. PROKARYOTES – EUBACTERIA, cont• Bacterial Pathogenesis

“Normal Flora” Some bacteria are opportunistic pathogens

Toxin Production

Exotoxins Bacterial proteins that can produce disease w/o the prokaryote present Examples include botulism, cholera

Endotoxins Components of gram negative membranes Examples include typhoid fever, Salmonella food poisoning

VI. PROKARYOTES – EUBACTERIA, cont

• Bacterial Pathogenesis, cont Examples

Clostridium sp.

Staphylococcus

Streptococcus

Neisseria sp.

Mycobacterium tuberculosis

EUKARYOTES

VII. KINGDOM PROTISTA• Very diverse• All __________________• Mostly _________________• Classified according to eukaryotic

kingdom protist is most like, nutrition Animal-like

Ingestive Protozoans

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 _________ ________________________

VII. KINGDOM PROTISTA, cont• Algae

Very important aquatic producers Phytoplankton Include

Dinoflagellates Red Tides

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

Brown Algae Kelp

Rhodophyta ______ Algae Seaweed Also found in coral reefs

Chlorophyta ________ Algae

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