Category: 2nd Semester

Bacteria

KINGDOMS ARCHAEBACTERIA & EUBACTERIA


All Materials © Cmassengale

Bacterial Evolution & Classification 

  • Most numerous organisms on earth
  • Earliest life forms (fossils date 2.5 billion years old)
  • Microscopic prokaryotes (no nucleus nor membrane-bound organelles)
  • Contain ribosomes
  • Infoldings of the cell membrane carry on photosynthesis & respiration
  • Surrounded by protective cell wall containing peptidoglycan (protein-carbohydrate)
  • Many are surrounded by a sticky, protective coating of sugars called the capsule or glycocalyx (can attach to other bacteria or host)
  • Have only one circular chromosome
  • Have small rings of DNA called plasmids
  • May have short, hairlike projections called pili on cell wall to attach to host or another bacteria when transferring genetic material
  • Most are unicellular

  • Found in most habitats
  • Most bacteria grow best at a pH of 6.5 to 7.0
  • Main decomposers of dead organisms so recycle nutrients
  • Some bacteria breakdown chemical & oil spills
  • Some cause disease 
  • Move by flagella, gliding over slime they secrete ( e.g. Myxobacteria)
  • Some can form protective endospores around the DNA when conditions become unfavorable; may stay inactive several years & then re-activate when conditions favorable
  • Classified by their structure, motility (ability to move), molecular composition, & reaction to stains (Gram stain)
  • Grouped into 2 kingdoms — Eubacteria (true bacteria) & Archaebacteria (ancient bacteria)
  • Once grouped together in the kingdom Monera

 

STRUCTURE FUNCTION
Cell Wall protects the cell and gives shape
Outer Membrane protects the cell against some antibiotics (only present in Gram negative cells)
Cell Membrane regulates movement of materials into and out of the cell; contains enzymes important to cellular respiration
Cytoplasm contains DNA, ribosomes, and organic compounds required to carry out life processes
Chromosome carries genetic information inherited from past generations
Plasmid contains some genes obtain through genetic recombination
Capsule, and slime layer protects the cell and assist in attaching the cell to other surfaces
Endospore protects the cell against harsh environmental conditions, such as heat or drought
Pilus (Pili) assist the cell in attaching to other surfaces, which is important for genetic recombination
Flagellum moves the cell

 

Kingdom Archaebacteria

  •   Found in harsh environments (undersea volcanic vents, acidic hot springs, salty water)
  • Cell walls without peptidoglycan
  • Subdivided into 3 groups based on their habitat — methanogens, thermoacidophiles, & extreme halophiles

Methanogens

  • Live in anaerobic environments (no oxygen)
  • Obtain energy by changing H2 and CO2 gas into methane gas
  • Found in swamps, marshes, sewage treatment plants, digestive tracts of animals
  • Break down cellulose for herbivores (cows)
  • Produce marsh gas or intestinal gas (methane)

Extreme Halophiles

  •   Live in very salty water
  •   Found in the Dead Sea, Great Salt Lake, etc.
  • Use salt to help generate ATP (energy)

Thermoacidophiles (Thermophiles)

  • Live in extremely hot  (1100C) and acidic (pH 2) water
  • Found in hot springs in Yellowstone National Park, in volcanic vents on land, & in cracks on the ocean floor that leak scalding acidic water

Kingdom Eubacteria (true bacteria)

  • Most bacteria in this kingdom
  • Come in 3 basic shapes — cocci (spheres), bacilli (rod shaped), spirilla (corkscrew shape)

  • Bacteria can occur in pairs ( diplo– bacilli or cocci)
  •   Bacteria occurring in chains are called strepto- bacilli or cocci
  • Bacteria in grapelike clusters are called staphylococci
  • Most are heterotrophic (can’t make their own food)
  • Can be aerobic (require oxygen) or anaerobic (don’t need oxygen)
  • Subdivided into 4 phyla — Cyanobacteria (blue-green bacteria), Spirochetes, Gram-positive, & Proteobacteria
  • Can be identified by Gram staining (gram positive or gram negative)  

Gram Staining

  • Developed in 1884 by Danish microbiologist, Hans Gram
  •   Bacteria are stained purple with Crystal Violet & iodine; rinsed with alcohol to decolorize; then restained with Safranin (red dye)

  • Bacterial cell walls either stain purple or reddish-pink

Gram-positive bacteria (Gram +)

  • Thick layer of peptidoglycan (protein-sugar) complex in cell walls & single layer of lipids
  • Stain purple

  • Lactobacilli are used to make yogurt, buttermilk ….
  • Actinomycetes make antibiotics like tetracycline & streptomycin
  • Disease-causing gram + bacteria produce poisons called toxins
  • Clostridium causes tetanus or lockjaw
  • Streptococcus cause infections such as “strep” throat

  • Staphylococci cause “staph” infections

  • Also cause toxic shock, bacterial pneumonia, botulism (food poisoning), & scarlet fever
  • Can be treated with penicillin (antibiotics) & sulfa drugs

Gram-negative bacteria (Gram -)

  • Cell walls have a thin layer of peptidoglycan & an extra layer of lipids on the outside
  • Stain pink or reddish 

  • Lipid layer prevents the purple stain & antibiotics from entering (antibiotic resistant)
  • Some are photosynthetic but make sulfur, not oxygen
  • Rhizobacteria grow in root nodules of legumes (soybeans, peanuts…) & fix nitrogen form the air for plants
  • Rickettsiae are parasitic bacteria carried by ticks that cause Rocky Mountain spotted fever
  • Spirochetes can cause syphilis & Lyme disease

Phylum Cyanobacteria

  • Gram negative
  •   Carry on photosynthesis & make oxygen
  • Called blue-green bacteria
  • Contain pigments called phycocyanin (red & blue) & chlorophyll a (green)
  •    May be red, yellow, green, brown, black, or blue-green
  • Some grow in chains (e.g. Oscillatoria)  & have specialized cells called heterocysts that fix nitrogen


OSCILLATORIA

  •  First bacteria to re-enter devastated areas
  • Anabaena that live on nitrates & phosphates in water can overpopulate & cause “population blooms” or eutrophication
  •   After eutrophication, the cyanobacteria die, decompose, & use up all the oxygen for fish

Phylum Spirochetes

  •   Gram positive
  • Have flagella at each end so move in a corkscrew motion
  •   Some are aerobic (require oxygen); others are anaerobic
  • May be free-living, parasitic, or live symbiotically with another organism  

Phylum Gram Positive bacteria

  • Most are Gram +, but some are Gram –
  • Lactobacilli grow in milk & make lactic acid (forms yogurt, cottage cheese, buttermilk) & also found on teeth & cause tooth decay
  • Actinomycetes grow in the soil & make antibiotics
  • Gram + members are found in the oral & intestinal cavities & slow the growth of disease-causing bacteria

Phylum Proteobacteria

  • Largest & most diverse bacterial group
  • Subdivided into Enteric bacteria, Chemoautotrophic bacteria, & Nitrogen-fixing bacteria  

Enteric bacteria

  • Gram negative heterotrophs
  • Can live in aerobic & anaerobic environments
  • Includes E. coli that lives in the intestinal tract making vitamin K & helping break down food
  • Salmonella causes food poisoning

Chemoautotrophs

  • Gram negative bacteria that obtain energy from minerals  
  • Iron-oxidizing bacteria found in freshwater ponds use iron salts for energy

Nitrogen-Fixing bacteria

  • Rhizobium are Gram negative & live in legume root nodules

  • 80% of atmosphere is N2, but plants can’t use nitrogen gas
  • Nitrogen-fixing bacteria change N2 into usable ammonia (NH3)
  • Important part of the Earth’s nitrogen cycle

Methods of Nutrition

  •  Saprobes feed on dead organic matter
  •  Parasites feed on a host cell
  •  Photoautotrophs use sunlight for energy, but get carbon from organic compounds (not CO2) to make their own food  
  • Chemoautotrophs obtain food by oxidizing inorganic substances like sulfur, instead of using sunlight

Methods of Respiration

  •   Obligate aerobic bacteria can’t live without oxygen; (tuberculosis bacteria)
  •  Obligate anaerobes die if oxygen is present; (tetanus bacteria that causes lockjaw)
  • Facultative anaerobes do not need oxygen, but don’t die if oxygen is present; (E. coli)
  • Anaerobes carry on fermentation, while aerobes carry on cellular respiration 

Bacterial Reproduction & Genetic Recombination

  • Most bacteria reproduce asexually by binary fission (chromosome replicates & then the cell divides)  
  •   Bacteria replicate (double in number) every 20 minutes under ideal conditions  
  • Bacteria contain much less DNA than eukaryotes
  • Bacterial plasmids are used in genetic engineering to carry new genes into other organisms  
  • Bacteria recombine genetic material in 3 ways — transformation, conjugation, & transduction

Conjugation

  • Sexual reproductive method
  • Two bacteria form a conjugation bridge or tube between them

  •   Pili hold the bacteria together
  •   DNA is transferred from one bacteria to the other       

Transformation

  • Bacteria pick up pieces of DNA from other dead bacterial cells
  • New bacterium is genetically different from original

Transduction

  • A bacteriophages (virus) carries a piece of DNA from one bacteria to another

  • Human insulin is produced in the lab by this method

Pathogenic bacteria

  •   Known as germs or pathogens
  • Cause disease
  • Can produce poisonous toxins
  • Endotoxins are made of lipids & carbohydrates by Gram – bacteria & released after the bacteria die (cause high fever, circulatory vessel damage…)
  • E. coli  produce endotoxins
  • Exotoxins are made of protein by Gram + bacteria 
  • Clostridium tetani produce exotoxins
  • Antibiotics interfere with cellular functions (Penicillin interferes with synthesis of the cell wall; tetracycline interferes with protein synthesis)
  • Some antibiotics are made by bacteria or fungi
  • Broad-spectrum antibiotics affect a wide variety of organisms
  • Bacteria can mutate and become antibiotic resistant (often results from overuse of antibiotics)
BACK

 

AR Wildflowers

Arkansas Wildflowers

 

 

Carolina Larkspur (Delphinum carolinium) – 4′ tall.
Blooms May – July.  These spurred flowers may be deep blue, reddish – blue, or white.  Native perennial.  OZ, OU, CP.

 

 Mexican Hat  (Ratibida columnifera) ― 2 – 3′ tall.
Blooms June – October.  A widely planted form of a native perennial.  Statewide.

 
Queen Ann’s Lace (Daucus carota)  ― 1 – 4′ tall

Blooms May – frost.  This is the ancestor of the cultivated carrot.  Introduced biennial. Statewide.

 

 Black-eyed Susan  (Rudbeckia hirta) ― 2 – 3′ tall with one 2″ flower head on each hairy stem.

Blooms May – October.  Native Biennial or short-lived perennial.  Statewide.

 

 

 

Showy Evening Primrose  (Oenothera speciosa) ― 1 – 2′ tall.

Blooms April – July.  White or pink flowers.  Native perennial.  Statewide.

 

 Pale Purple Coneflower (Echinacea pallida) – 3′ tall.

Blooms May – July.  Native perennial.  OZ, OU, CP.

 
Lance-leaved Coreopsis (Coreopsis lanceolata) – 3′ tall.

Blooms April – June.  Native perennial.  Statewide.

 

 Chicory  (Coreopsis intybus) – 4′ tall.

Blooms May – October.

This European native’s roots are sometimes used as a coffee substitute or additive.  Perennial.  OZ, OU.

 

 

 

 

Rough Blazing Star  (Liatrus aspera)  ― 3 – 4′ tall.
Blooms July – October.  The unopened flower buds resemble small cabbages.  Native perennial.  Statewide.

 

 Cardinal Flower (Lobelia cardinalis) – 3′ tall.
Blooms August – October. This flower attracts hummingbirds.  Native perennial. Statewide.

 
Arkansas Beard Tongue (Penstemon arkansanus) – Less than 2′ tall.
Blooms April – June.  The 3/4″ whitish flowers have lavender streaking.  Native perennial. OZ, OU.

 

 Purple Coneflower  (Echinacea purpurea) – Up to 4′ tall.
Blooms from June – October.
The ray flowers are more purple than those of pale purple coneflower. Native perennial. OZ, OU.
Downy Phlox (Phlox pilosa) – 2′ tall.

Blooms April – July.

Flowers can be pink, pale pink, or sometimes white with purple centers.  Native perennial.  OZ, OU, CP.

 

 Spider Lily (Hymenocallis caroliniana) – 3′ tall.

Blooms May – August.  These large white flowers have a distinctive spider-like shape. Native perennial. OU, GP, AP.

 
Rose Vervain (Glandularia canadensis) – Plants less than 2′ tall.

Blooms March – September.  The source of many garden hybrids.  Native perennial.  OZ, OU, CP, AP.

 

 Indian Paintbrush (Castilleja coccinea) ― 1 – 2′ tall.  The bracts that surround the small flowers displays brilliant colors.

Blooms April – June.  Native annual.  Found on prairies in the OZ, CP, AP.

 
Wild (Monarda fistulosa) ― 2 – 4′ tall.
Blooms June – September.  Also called Bee Balm.  Flowers pinkish, lavender, or lilac.  Statewide.

 

 Goldenrod (Solidago canadensis) ― 4 – 6′ tall.

Blooms July – September.  Native perennial.  Statewide.

 
Ohio Spiderwort (Tradescantia ohiensis) – Stems 3′ tall.
Blooms May – July.
So named because the internal jellylike substance resembles a spider’s web.  Native perennial.  OZ, OU, CP.		 Plains Coreopsis (Coreopsis tinctoria) – 3′ tall.

Blooms June – September.  Native annual.  Statewide.
Bird’s Foot Violet (Viola pedata) – 6″ tall.

Blooms April – May.  This violet occurs in several different colors:  light violet, dark violet, or dark violet with 2 dark purple petals. Native perennial.  OZ, OU, CP.

 

 Butterfly Weed (Asclepias tuberosa) ― 1 – 2′ tall.

Blooms May – September.  Flower’s nectar attractive to butterflies.  Native perennial.  Statewide.

 
Ox-eyed Daisy (Chrysanthemum leucanthemum) – 2″ flower heads.

Blooms May – July.  Introduced perennial.  OZ, OU, CP.

 

 Tickseed (Bidens aristosa) ― 1 – 6′ tall.

Blooms August – November.  This late bloomer is often found in large stands.  Native perennial.  Statewide.

 

 

 

Arthropod

Arthropods
Non-Insects

Characteristics

  • Makes up 3/4’s of all animal species
  • Includes insects, spiders, scorpions, millipedes, centipedes, crabs, lobsters, & crayfish
  • Arthropod means “jointed foot”
  • Jointed appendages (legs, antenna, mouthparts)
  • Segmented body with paired appendages on each segment)
  • External exoskeleton made of chitin (carbohydrate) & protein for protection & support
  • Exoskeleton has 3 layers — outer waxy layer repels water, middle layer has calcium for extra strength, & inner layer has flexible joints for movement
  • Protostomes (blastopore develops into mouth)
  • Coelomate (mesoderm-lined body cavity)
  • Ventral nervous system
  • Open circulatory system
  • Specialized sensory receptors & high degree of cephalization
  • Have simple or compound eyes & segmented antenna

Movement & Growth

  • Muscles occur in bundles & are attached to inside of exoskeleton on each side of joints
  • Exoskeleton must be periodically molted (shed) for organism to grow
  • Molting called ecdysis
  • Molting hormone released & causes epidermal cells to secrete enzymes that digest & loosen inner exoskeleton
  • New exoskeleton secreted by epidermal cells flexible at first & must harden so arthropod not vulnerable to predators so often stay in hiding after molting
  • Arthropods go through numerous molts


Butterfly Molting Pupal Case

Evolution & Taxonomy

  • Evolved from ancestral arthropod with many body segments each with appendages
  • Modern arthropod segments fused into larger, specialized structures called tagmata
  • Four subphyla
    * Trilobita – extinct trilobites
    * Crustacea – shrimps, lobsters, crayfish, & barnacles
    * Chelicerata – spiders, scorpions, & ticks
    * Uniramia -centipedes, millipedes, & insects

Subphylum Trilobita
Characteristics

  • Includes extinct trilobite
  • Marine
  • Have a head & segmented trunk with one pair of legs on each segment
  • Breathe through gills
  • Single pair of antenna


TRILOBITE

Subphylum Chelicerata
Characteristics

  • Includes 2 classes — Xiphosura (horseshoe crab) and Arachnida (spiders, ticks, scorpions, & mites)
  • Have a cephalothorax (fused head& thorax) and abdomen
  • No antenna
  • Simple eyes or ocelli
  • Have 6 pairs of jointed appendages:
    * Chelicerae – claws or fangs (1 pair)
    * Pedipalps – used for feeding, walking, sensing, transferring sperm (1 pair)
    * Walking legs – movement (4 pairs)
  • Horseshoe crab
    * Marine
    * Not true crabs
    * Fanglike pincers or chelicerae
    * Use book gills to breathe


HORSESHOE CRAB

  • Arachnids
    * Terrestrial
    * Eight legs
    * Chelicerae or fangs with venom
    * Ocelli
    * No antenna
    * Breathe by book lungs &/or tracheal tubes
  • Spiders
    * Arachnid that feeds on insects (carnivores)
    *  Have oval shaped, unsegmented abdomen
    * Cephalothorax connected by narrow waist to abdomen
    * Have 8 simple eyes or ocelli
    * Fangs pierce prey, inject poison, & suck out body fluids
    * Pedipalps on head help sense prey & move it to the mouth
    * Open circulatory system
    * Ostia are openings in heart where blood reenters
    * Body cavity called hemocoel
    * Hemocycanin is oxygen-carrying pigment in blood
    * Have silk glands to make silk & spinnerets to release silk for webs
    * Breathe by book lungs & tracheal tubes
    * Malpighian tubules filter wastes & reabsorb water


GARDEN SPIDER

  • Ticks & Mites
    * Parasitic arachnid
    * Fused cephalothorax & abdomen
    * Most abundant arachnid
    * Need blood meal to molt
    * Mites can damage fruit & feed on dead skin at base of hair follicle
    * Ticks carry Lyme disease & Rocky Mountain Spotted Fever

 


MITE
TICK

 

  • Scorpions
    * Have a cephalothorax & long segmented abdomen curled over body
    * Prefer dry regions
    * Poisonous stinger on end of abdomen
    * Breathe through book lungs
    * Pedipalps modified into claws
    * Nocturnal predators


SCORPION

Subphylum Crustacea
Characteristics

  • Marine members include shrimp, lobster, copepods, barnacles, & crabs

 

CRAB SHRIMP

 

  • Terrestrial crustaceans called isopods include pillbugs & sowbugs


PILLBUG

  • Freshwater members include crayfish & Daphnia (water fleas)


DAPHNIA

  • All have jaws are mandibles for chewing or tearing
  • Known as mandibulates
  • Have cephalothorax & abdomen
  • Have 10 pairs of jointed appendages
  • Breathe through gills
  • Barnacles
    * Marine
    * Sessile crustaceans that live in limestone case
    * Filter plankton with 12 appendages called cirri


BARNACLE

  • Isopods (pillbugs & sowbugs)
    * Live on land in dark places
    * Have 7 pairs of legs on a segmented body
    * Can roll into a ball for protection
  • Crayfish
    * Cephalothorax made of 13 fused segments & covered by protective carapace
    * Antennules located on head help in balance, touch, & taste
    * Statocysts – balancing organs at the base of antennules
    * Antenna on head used for touch & taste
    * Maxillae – paired mouthparts that move side to side to tear food
    * Maxillipeds – help hold food
    * Chelipeds – claws used to capture food & for protection
    * Mandibles – jaws that move up & down to crush  food
    * Walking legs – 8 pairs used for movement
    * Swimmerets – under abdomen to swim, gas exchange, & protect eggs/young
    * Abdomen ends in flat segment called telson with flat uropods on each side


CRAYFISH

               * Compound eyes on stalks
* Chitinous teeth in stomach grind food
* Wastes leave through anus
*  Green glands filter wastes from blood & help with salt balance
*  Open circulatory system with heart to pump blood to gills & body cells
* Ostia – one way valves allowing blood from dorsal sinus to reenter heart
* Gills attached to walking legs
* Separate sexes that mate in fall & sperm stored in seminal receptacle
*  Eggs attach to swimmerets of female & hatch in several weeks

  • Copepods
    * Largest group of crustaceans
    *  Make up most of the marine plankton
    *  Serve as food for many marine animals
    *  Found in freshwater, marine, & moist terrestrial environments


COPEPOD

Subphylum Uniramia
Characteristics

  • All have antenna, mandibles (jaws), & unbranched appendages
  • Includes 3 classes — Chilopoda (centipedes), Diplopoda (millipedes), & Insecta
  • Known as myriapods
  • Most are terrestrial
  • Exoskeleton prevents desiccation (water loss)

Class Chilopoda

  • Terrestrial centipedes
  • Flattened body with longer legs for fast movement
  • Have 1 pair of legs per body segment
  • Predators
  • Mandibles & maxilla for chewing prey (insects & earthworms)
  • Claw-like appendages or pincers on 1st body segment that can inject venom
  • Can coil up for defense


CENTIPEDE

Class Diplopoda

  • Terrestrial millipedes
  • Have 2 pairs of legs per body segment
  • Rounded body
  • Scavengers on decaying vegetation as they burrow through soil
  • Roll into ball when threatened & spray noxious chemical containing cyanide


MILLIPEDE

BACK

 

AP Lecture Guide 18 – Microbial Models

AP Biology: CHAPTER 18

MICROBIAL MODELS

1. What makes microbes good models to study molecular mechanisms?

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2. List several characteristics of viruses.

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3. What are the two basic components of viruses? ___________________________________

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4. Use the diagram to help explain typical viral reproduction.

 

5. Identify the cycle used by the virulent phage.

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6. Compare the lytic and lysogenic cycles.

 

 

7. What is the role of the viral envelope?

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8. Outline the steps in the life cycle of the envelope viruses.

 

 

9. Review the life cycle of the HIV virus.

 

 

 

10. What is reverse transcriptase and why is it important in biotechnology?

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11. What is a vaccine?

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12. Where do emerging viruses come from?

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13. What is a viroid? Give some examples.

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14. What is a prion and what do they do to the cells?

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15. List and describe the three basic shapes of bacteria used for classification.

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16. Most bacteria are not pathogenic. Identify several important roles they play in the ecosystem

and human culture.

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17. How do variations arise in bacteria considering they reproduce mostly by asexual means?

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18. Define bacterial transformation.

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19. How does transduction differ from transformation?

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20. What is a plasmid and identify its role in bacterial conjugation?

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21. What is the major method utilized by bacteria to pass along resistance to antibiotics?

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22. What is a transposon?

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23. Describe potential problems caused by transposons.

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24. E. coli use a regulatory system called an operon. Identify the components with their functions of the operon.

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25. Use the diagram of the Tryp operon to outline how it regulated tryptophan levels.

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26. Describe how the trp operon is a repressible operon.

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27. Use the diagram of the lac operon to outline how it regulates glucose levels.

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28. Does the diagram above represent the condition for the absence or presence of lactose?

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29. Describe what happens when lactose is absent.

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30. How is the lac operon an inducible system?

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31. Summarize how the presence and absence of glucose influences the lac operon.

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AP Lecture Guide 26 – Origin of Life

 

 

AP Biology: CHAPTER 26: ORIGIN OF LIFE

 

1. Start with the origin of the earth and identify the time frame, conditions, and evidence for

each of the following steps leading to current life forms on earth.

a. Origin of the earth ________________________________________________________

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b. Prokaryotes _____________________________________________________________

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c. Oxidizing atmosphere _____________________________________________________

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d. Eukaryotic cells __________________________________________________________

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e. Multicellular life __________________________________________________________

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2. What was significant about the discovery of the iron oxide bands in the sedimentary layers.

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3. Describe the theory of endosymbiosis. ___________________________________________

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4. Why did evolution seem to slow 750 to 570 million years ago?

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5. What was special about the Cambrium Explosion?

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6. Describe a few adaptations essential for the invasion of plants onto land.

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7. Scientific Hypothesis for the origin of life

a. The first cells may have originated by chemical evolution on a young Earth

b. Abiotic synthesis of organic monomers is a testable hypothesis

c. Laboratory simulations of early-Earth conditions have produced organic polymers

d. RNA may have been the first genetic material

e. Protobionts can form by self-assembly

f. Natural selection could refine protobionts containing hereditary information

g. Debate about the origin of life abounds

8. Describe the hypothesized conditions on earth when life arose. _______________________

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9. What did Louis Pasteur demonstrate with his experiment? ___________________________

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10. List the four stages for the formation of life.

a. _______________________________________________________________________

b. _______________________________________________________________________

c. _______________________________________________________________________

d. _______________________________________________________________________

11. What metabolic processes would you expect to see in protobionts?

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12. Why is RNA now thought to be the first genetic code?

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13. What did Oparin, Haldane, Miller and Urey accomplish?

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14. What are some of the possible locations for the first life forms?

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15. What is the basis of the classification system developed by Linneaus?

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16. Why is taxonomy considered a work in progress?

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17. What are two problems with the five kingdom system of classification?

a. ________________________________________________________________________

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b. ________________________________________________________________________

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18. How has the Domain System altered our view of taxonomy?

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19. Which prokaryote is closer to the eukaryotes? List several reasons for your answer.

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20. Place the following metabolic processes in an order that fits this hypothesis for the origin of

life: Photosynthesis, Aerobic Respiration, Fermentation, Nucleic Acid replication (RNA or

DNA), Membrane transport

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21. Label the diagram to explain the Miller and Urey experiment to test the Abiotic Synthesis

hypothesis.

22. Label the diagram to indicate the major events, the time frame, and the geologic eras the

origin of life on Earth.