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Extra stuff that is on 1st test

Properties of Life (pg. 24-25)Viruses (pg. 38)Taxonomy (382-384)Heterotrophs/autotrophs – 105Natural selection (310-312)Endosymbiosis (57, 68-71)Autotrophs, heterotroph, photo

synthesis & chemosynthesis (p.398)

Metabolism

•Getting, storing and using energy•Producers (aka “autotrophs”) produce own food

Photosynthesis Chemosynthesis

•Consumers (aka “heterotrophs”) consume other organisms

Eat producers or other consumers

pg. 14

Capturing energy: photosynthesis

…and pea aphids!!

Evolution(Darwin doesn’t matter)

Somebody else would have figured it out (….and did)Details later

What Is Evolution

Change in a population (not an individual)

Two requirements1. Variation in the population (often random)2. Selection (NOT random – more info later)

Quick overview. We’ll do Unit 3 near end of class

Adaptation

Organisms better suited to their environment will leave more offspring

Population will change over time (evolution) to better fit conditions of environment

Adaptive traits and “fitness”pg. 15

Why viruses are not “alive”

GrowthReproduction (need host to do it)HomeostasisSense and respond to stimuli (probably not)Ability to obtain and use energy

Why we don’t use antibiotics for viral infections

At least two parts in all viruses

1. Nucleic acid core2. Protein coat

Many viruses also have capsule made of membranes stolen from their host cell

If bacteria detect the viral nucleic acids, they will make restriction enzymes to destroy them. We use restriction enzymes in biotech as “sissors” to cut DNA

Species“Organisms that breed in natural surroundings and create fertile offspring”

One of the most common definitions of species. See slothnet links for MANY other definitions!!!!

populationA group within a species that has a common habitat

How many species are there on Earth, and how do scientists keep track of them?

Estimated 5 million to 30 million total number of species on Earth

1.5 million or so have been formally described

TaxonomyPg. 382-384

How many species are there on Earth, and

how do scientists keep track of them?

Taxonomysystematicall

y identifying, naming, and classifying organisms on the basis of shared traits

Carolus Linnaeus

Book Illustration(next slide, Animals!!!)

We’ve added a newlevel since Linnaeus(more info later)

GeneralVerySpecific

The larger groups are less specific and contain more kinds of organisms

Species Name put it in italics or underline it1) Genus must be capitalized (e.g. Canis)2) specific to the species must be lower case

Scientific Name (2 parts)

Canis lupusCanis latrans

Panthera tigrisFelis silvestris

Felis nigripes

Same Genus – closely relatedSame Family – less related

Same Order – distantly related

Order Carnivora

Ursus americanus

Eukaryotes = Eu(“with”) + karyo(“kernel”; i.e. nucleus)Most stuff: plants, animals, fungi, many microbes

Prokaryotes = Pro(“before”) + karyo(“kernel”; i.e. nucleus)

very little cells without a nucleus

Go read Chapter 18 Prokaryotes are on 1st test!!!

Terms change over time “bacteria” “Eubacteria “ & “Archebacteria” “Bacteria” & “Archea”

Prokaryotic domains see

chapter 18

Prokaryotes – two domains

BacteriaSmall cellsAsexual reproductionNo nucleus (“prokaryote”) bacteial chromosome plasmid – DNA loop

NO ORGANELLES

ArcheaSmall like bacteriaNo nucleus (“prokaryote”) or OrganellesMany can live in extreme conditions

thermatogenshalophiles

Neither one has DNA in nucleus

Bacteria Most possess a cell wall (mostly peptidoglycans) Tremendous genetic diversity Differences in nutrition, metabolism, structure, and

lifestyle

Autotrophs: make their own food from material in nonliving environment

Photosynthesis (“cyanobacteria”) Chemosynthesis (e.g. deep sea hot vents)

Heterotrophs: rely on other organisms as a food source Decomposers Fermenters Symbionts - (e.g. Vibrio fischeri in light organs of squid) pathogens

Many antibiotics work by messing with bacteria’s ability to make or repair wall

Bacteria: structure

Spherical (cocci)Rod-shaped (bacilli)Spiral (spirochetes)Flagella: tiny whiplike structures that

project from the cell and help it movePili: shorter, hairlike appendages that

enable bacteria to adhere to a surfaceCapsule: sticky coating surrounding cells

help adhere to surfaces and protects cells

Bacteria

ArchaeaSimilar to

bacteriaLack a nucleusGenetically

distinct“Extremophiles”

◦hyperthermophiles

◦methanogens◦halophiles

Eukaryotes – One Domain

Four kingdoms – all have DNA in nucleus

Animals = kingdom AnimaliaPlants = kingdom PlantaeFungi = Kingdom FungiProtists = Kingdom Protista

algae, amoeba, lots of microbes (e.g. Noctiluca)

Eukaryotes - characteristicsHave a nucleus (that’s where DNA)Have organelles (little parts with separate jobs)

mitochondria – make energy (the power plant)golgi aparatus – chemicals are packaged/modifiedendoplasmic reticulum – manufacturing (factory)vacuole – storage (warehouse)

Endosymbiont Theory

Will cover in detail when we study cells – lab & lecture

Endosymbiosis

Endosymbiosis = endo(“within”) + sym(“same”) + bio

The idea that complex cells (eukaryotes) formed when small cells started living inside big cells

evidence: double membrane, ribosomes, DNA

Evolution of eukaryotic cellsEndosymbiosis theory pg. 66-73

Free-living prokaryotic cells engulfed other free-living prokaryotic cells billions of years ago, forming eukaryotic organelles

Mitochondria and chloroplasts

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