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Course: BIOL 117 General Biology 2 Lab Instructor: Anne Rybicki, PhDEmail: acrybicki@gmail.com or contact me through Blackboard Course description: This course examines the mechanisms of evolution through the exploration of the five kingdoms of life, both on the basis of their unique anatomical structures and adaptations as well as those conserved through evolutionRequired Texts:Explorations in General Biology Laboratory, Eileen Walsh, 2011 (ISBN 978-0-7575-8927-0)I will post the Powerpoint intro to each lab on Blackboard after class each week Attendance: Attendance is required and will be taken at every lab period; students must arrive on time and stay for the entire lab period; there will be no makeup lab quizzes; exams can only be made-up if you have a valid excuse and you notify the instructor before the exam. Please read the assigned lab investigation before coming to labGrading: Your grade in the lab will comprise 25% of your course grade. It is a departmental policy that a student must receive a minimum grade of 50 to receive credit for the courseThe lab grade will be determined byLab work (taxonomic key): 10% (I will also check your lab books)Tests (3 tests): 90% (tests will be both written and practical)Students at Westchester Community College must abide by the Honor Code. Anyone caught cheating on an exam will receive a grade of 0 for that exam. Additionally, the Chairman and Provost will be informed in writing and the student will receive an F for the courseStudent obligations:No eating/drinking in the lab and please set your cell phones to silent mode. You must leave your work area the same as you found it (clean; all equipment put away) Lab 1 (1/23): Exercise 14 Classification and survey of the kingdoms: prokaryote; protista; and fungiLab 2 (1/30): Exercise 15 Bryophyta; Exercise 16 PterophytaLab 3 (2/6): Exercise 17 Coniferophyta; Exercise 18 AnthophytaLab 4 (2/13): Test 1Lab 5 (2/20): Exercise 19 Anatomy of the flowering plantLab 6 (2/27): Exercise 19 Anatomy of the flowering plantLab 7 (3/6): Test 2Lab 8 (3/13): Exercise 20 Porifera; Exercise 21 CnidariaSpring break 3/17-3/23Lab 9 (3/27): Exercise 22 Annelids; Exercise 23 MolluscsLab 10 (4/3): Exercise 24 Arthropods; Exercise 25 EchinodermsLab 11 (4/10): Test 3Lab 12 (4/17): Exercise 26 Fetal pigLab 13 (4/24): Exercise 26 Fetal pigLab 14 (5/1): Exercise 31 Use and construction of a taxonomic key dueLab 15 (5/8): Test 4 (given the week before Finals week)

Taxonomy is that branch of biology dealing with the identification and naming of organisms

Five kingdoms based on their cell structure and sources of nutrition:

1-Monera: includes Eubacteria and Archaebacteria; heterotrophic and autotrophic prokaryotes

2-Protista: heterotrophic and autotrophic eukaryotes

3-Fungi: heterotrophic

4-Plantae: autotrophic

5-Animalia: heterotrophicAutotrophs- organisms that are able to make energy-containing organic molecules from inorganic raw material by using basic energy sources such as sunlight (plant kingdom) Heterotrophs- organism that obtains organic food molecules by eating other organisms (animal kingdom)

Carolus Linneus, a Swedish botanist, developed the concept of binomial nomenclature, whereby scientists speaking and writing different languages could organize biological organisms; when writing genus and species information, the Genus is always capitalized, the species lower-case, and both are italicized e.g. Homo sapiensLinnean hierarchical classification was based on the premise that the species was the smallest unit, and that each species nested within a higher categorySpecies- organisms that can interbreed and produce viable, fertile offspring

Human Taxonomy

Kingdom AnimaliaPhylum (Division for plants) Chordata Class Mammalia Order Primates Family Hominidae Genus Homo species sapiens

Earliest organismsDomain Bacteria Domain Archaea Found in extreme habitats; live without oxygenKingdom Protists

Kingdom MoneraKingdomPlantaeDomain EukaryoteKingdomFungiKingdomAnimaliaThe Structure and Function of ProkaryotesProkaryotic cellsLack true nuclei; the nucleoid is a region where the circular chromosome (DNA) is locatedPlasmids are accessory rings of DNALack other membrane-enclosed organelles; ribosomes are the only cytoplasmic organelles. They are smaller than eukaryote ribosomesHave cell walls exterior to their plasma membranes; the cell wall prevents bursting or shrinking when the osmotic concentration changesThe cell is surrounded by a capsule (attached) and/or by a loose gelatinous sheath (slime layer). This layer helps attach the cell to attach to environmental surfaces. Many prokaryotes adhere to surfaces by short hair-like structures called pili or fimbriae.Some move by means of flagella; the flagellum contains a hook and a basal body. It rotates 360 degrees to propel the cell.

Plasma membrane(encloses cytoplasm)Cell wall (providesRigidity)Capsule (stickycoating)Prokaryoticflagellum(for propulsion)Ribosomes(synthesizeproteins)Nucleoid(contains DNA)Pili (attachment structures)Prokaryotes

SHAPES OF PROKARYOTIC CELLSSpherical (cocci)Rod-shaped (bacilli)SpiralLab exercise-observe slideEubacteria- characterized according to their shape, motility (presence of a trichus), and composition of their cell wallsProkaryotes come in several shapes:Spherical (cocci)Rod-shaped (bacilli)Spiral

Streptococci (filamentous)

Staphlococci (divide along multiple axes)

A Gram stain of mixed Staphlococcus aureus (Gram positive cocci) and Escherichia coli (Gram negative bacilli); Gram-positive: Thick peptidoglycan wall becomes dehydrated and retains the crystal violet purple stainGram-negative: Need a pink counterstain (safanin) because the crystal violet stain is not retained (lipopolysaccharides in outer wall dissolve with alcohol) Gram-positive bacteria have cell walls that are made up of 50-90% peptidoglycan. When crystal violet stain is used to stain the bacteria and the decolorizer (alcohol) is added, the thick cell wall becomes dehydrated and traps the crystal violet inside the bacteria; gram-positive bacteria stain purpleGram-negative bacteria generally possess a thin layer of peptidoglycan between two membranes. After the bacteria are stained with crystal violet, the decolorizer (alcohol) removes the outer cell membrane and the crystal violet is also lost; gram-negative bacteria stain pink with the safanin counterstain

Cyanobacteria: blue-green in color, which is why they are often called blue-green bacteria. They are common in ponds, lakes, streams and moist areas of land. They are composed of chains of bacteria (filamentous) and contain phycocyanin, a bluish pigment that absorbs light, and chlorophyll, a pigment involved in photosynthesis, a process that uses the suns energy to make sugar molecules. Cyanobacteria are photosynthetic prokaryotes

Oscillatoria is a genus of filamentous cyanobacterium which is named for the oscillation in its movement. Filaments in the colonies can slide back and forth against each other until the whole mass is reoriented to its light source

Anabena- a genus of filamentous cyanobacteria that exists as plankton. It found in colonies and is known for its nitrogen fixing abilities. During times of low environmental nitrogen, about one cell out of every ten will differentiate into a heterocyst (lacking pigmentation). Heterocysts then supply neighboring cells with fixed nitrogen in return for the products of photosynthesis (sugars), that they can no longer perform. This separation of functions is essential because the nitrogen fixing enzyme in heterocysts, nitrogenase, is unstable in the presence of oxygen. heterocystLab exercise-observe slideKingdom: ProtistsProtists are not one distinct group but instead represent all the eukaryotes that are not plants, animals, or fungi.Protists differ from prokaryotes because they are eukaryotes that have a nucleus and contain DNA in chromosomesProtists are divided into three groups based on physical characteristics (locomotion) and modes of nutrition: protozoa (animal-like protists); heterotrophs (ingest food particles) algae (plant-like protists; includes seaweeds); photoautotrophs (make food through photosynthesis) slime molds (fungal-like protists); chemoheterotrophs (absorb organic molecules)Animal-like protists have 3 different modes of locomotion: flagella, cilia, and pseudopods; includes Paramecium, Euglena, and AmoebaMost species of Euglena have photosynthesizing chloroplasts within the body of the cell, which enable them to feed by autotrophy, like plants. However, they can also take nourishment heterotrophically, like animals. They are considered mixotrophs, an organism that can use a mix of different sources of energy and carbonLab exercise-observe slide

Euglena gracilis

Lab exercise-observe slide

Amoeba proteusFood beingingestedPseudopodiumof amoebaLab exercise-observe slidePlant-like protists contain plastids which are very similar to chloroplasts; may be that a cyanobacteria became an organelle in a protist cell by endosymbiosis

Plant-like protists include diatoms and SpirogyraUnicellular algae are diatoms in the Phylum Bacillariophyta. Some have shells composed of silica. Most are photosynthetic and are an important part of the aquatic ecosystem known as plankton. They produce much of the oxygen we breathe, and also take in much of the carbon dioxide from the atmosphere

The siliceous shells of diatoms have many uses, such as in reflective paint, in toothpaste, or as a filter (diatomaceous earth)

Lab exercise-observe slideSpirogyra is a genus of filamentous green algae named for the helical or spiral arrangement of the chloroplasts. It also has a large central vacuole

Lab exercise-observe slideMost protists are unicellular and can live independently or in colonies (filamentous organisms). Some protists are truly multicellular where the cells within the organism are specialized for different purposes. Brown algae (kelp; Laminaria) in the Phylum Phaeophyta is multicellular with different body structures e.g. the holdfast that attaches the kelp to an immovable surface

Fungal-like protistsPhylum Myxomycota contains plasmodial slime molds such as Physarum. They reproduce sexually and contain haploid and diploid forms during their life cycle. The diploid feeding stage of the organism is known as a plasmodium due to a process called syngamy (when cells fuse); the plasmodium is therefore multinucleated. Under dry conditions (or when food is scarce), stalked reproductive structures called sporangia form. Haploid spores are formed by meiosis. Under wet conditions, the haploid spores germinate and fuse before fertilization.

Feeding stagedrywetLab exercise-observe slide

When it is wet, the spores germinate; when it is dry, the stalks form and spores are produced

Animal-like protistAnimal-like protistAnimal-like protistPlant-like protistFungal-like protist

A model for the evolution of multicellular organisms from unicellular protists.UnicellularprotistColonyEarly multicellular organismwith specialized, interdependent cellsLocomotorcellsFood-synthesizingcellsLater organism withgametes and somatic cellsSomaticcellsGameteMulticellular eukaryotes include fungi, plants, and animals

Fungi are multicellular eukaryotes

Multicellularity is a big step in evolution because organisms with many cells can then use different cells for specific functions; they can also grow larger

Kingdom Fungi Decomposers- break down organic material and recycle vital nutrients; saprotrophic- decompose dead matter Fungi are heterotrophs and absorb nutrients from outside their bodies They use enzymes to breakdown complex molecules into simpler ones Body structures: multicellular fungi and single cells (yeasts) The morphology of multicellular fungi enhances their ability to absorb nutrients They are composed of mycelia, networks of branched hyphae adapted for absorption Most fungi have cell wall made of chitin (plant cell walls have cellulose and pectin; bacterial cell walls have proteoglycan)

3 phyla: zygomycetes, ascomycetes, basidiomycetes based on type of reproductive structures

1-Phylum Zygomycetes Zygosporangia (sexually produced reproductive structures), which are resistant to freezing and drying, can survive unfavorable conditions Black bread mold Rhizopus nigricans Hyphae absorb nutrients During sexual reproduction, the haploid gametes from + and strains fuse (zygote) and then form a thick zygospore in which meiosis occurs forming haploid spores Upon germination, a sporangium is formed and haploid spores released

Lab exercise-observe petri dish

HyphaeMyceliaSporangiaSpores

Life cycle of RhizopusZygosporangium resistant to harsh conditionsFusion of hyphaeSexual reproductionFusion of nucleiSexual reproduction-fusion of hyphae (plasmogamy); fusion of nuclei (karyogamy); production of spores in zygosporangia (meiosis)

Asexual reproduction- germination of haploid spores by mitosis to form mycelia

2-Phylum Ascomycetes Called sac fungi Sexually, produce haploid spores in sacs called asci Asexually, produce spores called conidia in projections of hyphae called conidiophores Sac fungi also include unicellular yeasts (Saccaromyces or bakers yeast) and the multicellular morels, truffles, and Penicillium

conidia

Budding yeast: Saccharomyces cerevisiae (Ascomycetes)

Lab exercise-observe slideDifference between conidia and ascospores.Conidia tips of specialized hyphae, haploid, spores for wind dispersal (asexual)

Ascospores haploid mycelia of opposite mating strains fuse and develop spores within an ascus (sexual)

3-Phylum Basidiomycota- edible mushrooms; Basidiomycota (basidio=little base) are filamentous fungi composed of hyphae and produce sexual spores (basidiospores); includes Coprinus

stipecapGills- plates within the cap of the basidiomycetes where spores are producedLab exercise-observe Coprinus

In response to environmental stimuli, the mycelium reproduces sexually by producing fruiting bodies called basidiocarps; spores= basidiosporesbasidiocarp