Bio Lab notes

Lab 1 - Classification and Microscopy

  • What is a cladogram?

    • A cladogram is a branching, tree-like diagram used in biology to represent a hypothesis of evolutionary relationships and common ancestry among species.

  • What is a dichotomous key?

    • A scientific tool used to identify unknown organisms by choosing between two contrasting characteristics in a series of steps.

    • Interpretation: Can you interpret a basic dichotomous key?

  • What does pathogenic mean?

    • Refers to a bacterium or infection that causes disease.

  • What does ubiquitous mean?

    • Present, appearing, or found anywhere.

  • What do Gram positive bacterial cells look like?

    • They appear purple after staining.

  • What do Gram negative bacterial cells look like?

    • They are pink after staining.

  • What are the 3 basic shapes of bacterial cells?

    1. Cocci - spherical shape.

    2. Bacilli - rod-shaped.

    3. Spirilla - spiral-shaped.

  • Identification of Compound Light Microscope Parts:

    • If shown a photo, can you identify some of its major parts?

  • How to Calculate Final Magnification on a Microscope:

    • Multiply the magnification power of the eyepiece by the magnification power of the objective lens.

    • Example: 10x eyepiece multiplied by 40x objective lens to get a final magnification.

Lab 2 - Survey of Protists

  • What is an outgroup?

    • A distantly related organism that serves as a reference point and was diverged earlier than the ingroup.

  • What is a node?

    • A branching point from an ancestor.

  • What is an ancestral character?

    • A trait inherited from a common ancestor that appears in early lineage evolutionary history.

  • What is a derived character?

    • A character that evolved in the most recent common ancestor, distinguishing them from ancestral forms.

  • How are living organisms classified?

    • Using a hierarchical, Linnean taxonomic system based on shared characteristics, evolutionary relationships, and genetic similarities.

    • 3 Domains of Life:

    1. Archaea

    2. Bacteria

    3. Eukarya

    • 4 Kingdoms of Domain Eukarya:

    1. Protista

    2. Plantae

    3. Animalia

    4. Fungi

    • Taxa from Most Inclusive to Least Inclusive:

    • Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species.

  • General characteristics of protists:

    • They live in moist, aquatic environments.

    • Exhibit complex cell structures with nuclei.

    • Can be motile or non-motile.

    • Routes of nutrition include autotrophic and heterotrophic.

    • They can reproduce asexually or sexually.

  • Life cycle(s) of a protist:

    1. Binary fission (alternation of generations).

    2. Sexual reproduction (conjugation).

  • Definition of protozoa:

    • Single-celled microscopic eukaryotic organisms.

  • Protozoan Phyla discussed in lab:

    1. Amoeba

    2. Euglena

    3. Paramecium

  • Unique Characteristics of Protozoan Species:

    • Euglena:

    • Motile, light-sensitive red eyespot, flagella for swimming.

    • Amoeba:

    • Movement and feeding through pseudopodia.

    • Contains a contractile vacuole for water regulation.

    • Paramecium:

    • Covered in cilia.

    • Possesses contractile vacuoles and a micro and macronucleus.

    • Plasmodium:

    • Complex, multi-host lifecycle (human and mosquito), contains apicoplast.

  • Steps to Wet Mount Procedure for a Protist:

    1. Grab a microscope slide.

    2. Using the appropriately labeled pipette, gently expel some of the protozoan mixture in the center of your slide.

    3. Using ProtoSlo, gently expel one droplet in the center of the protozoan mixture.

    4. Place a coverslip over the circle.

    5. Observe under your microscope, and identify the protozoan species using the dichotomous key.

  • Suffix -phyta Meaning:

    • Translates to “plant.”

  • Four Protist Algal Phyla:

    1. Euglenophyta

    2. Dinoflagellata

    3. Diatoms

    4. Brown Algae

    • Name Interpretations:

    • Euglene refers to the red eyespot.

    • Dinoflagella means spinning flagella.

    • Diatoms are made of silica (glass) and can mask green chlorophyll to create a brown appearance; found in water as seaweeds.

Green Algae Species Characteristics

  • Unique Characteristics of Each Species:

    • Chlamydomonas:

    • Has 2 anterior flagella and a cup-shaped chloroplast with a pigmented eyespot; reproduces zygotic meiosis.

    • Volvox:

    • Motile, forms colonial large spheres that contain several daughter colonies.

    • Gonium:

    • Motile, colonial, and flattened, held together by gelatinous material.

    • Hydrodictyon:

    • Non-motile, colonial; branched multinucleate cells separated by cross walls.

    • Oedogonium:

    • Non-motile, colonial, filamentous, and unbranched filaments.

    • Ulva:

    • Multicellular; relatively large, with a mature body flattened into a tissue-like sheet; referred to as “sea lettuce”; reproduces through sporic meiosis.

  • Identification of Algal Types:

    • If shown a pressed specimen of brown or red algae, could you identify it as brown (Phaeophyta) or red (Rhodophyta)?

    • If shown a photo of any organism observed in the protist lab, could you correctly identify its genus name?

Lab 3 - Survey of Fungi

  • Difference Between Fungal and Plant Cell Walls:

    • Fungal walls are composed of chitin, whereas plant cell walls are made of cellulose.

  • Definition of Hyphae:

    • A thin, cell-like filament that branches out to grow and vegetate.

  • What is Mycelium?

    • A large mass of hyphae that forms a root-like structure, typically grows outward rather than increasing in girth.

  • How do Fungi Primarily Reproduce?

    • Through both asexual and sexual methods, germinating into new individuals and producing spores.

  • General Life Cycle of a Fungus:

    • Characterized as a haploid-dominant process, centered on the production of spores, and includes both sexual and asexual phases, often involving symbiosis with mycorrhizae and hyphae.

  • Imperfect vs. Perfect Fungi:

    • Perfect Fungi: Produce both sexually and asexually, allowing for genetic recombination.

    • Imperfect Fungi: Only reproduce asexually and lack a sexual stage (known as Deuteromycetes).

  • Plasmogamy vs. Karyogamy:

    • Plasmogamy: The union of the two parent mycelium cytoplasms.

    • Karyogamy: The fusion of two haploid nuclei.

  • Features of Phylum Ascomycota:

    • Key structures include ascus (sac) and ascospores, featuring a haploid and asexual lifecycle.

  • Conidia and Conidiophores:

    • Conidia are asexual, non-motile fungal spores produced externally on hyphae.

    • Conidiophores are the stalks that support and disperse spores for reproduction.

  • Examples of Imperfect Fungi:

    • Penicillium and Aspergillus.

  • Features of Phylum Basidiomycota:

    • Basidiospore are the sexual spores, basidocarp is a mushroom, and basidium is the club-shaped reproductive organ found on the pores of a basidocarp.

  • Types of Lichens:

    • Can you identify if given a photo?

    1. Crustose

    2. Foliose

    3. Fruticose

Lab 4 - Survey of Nonvascular Plants

  • Three Phyla Representing Non-Vascular Plants:

    1. Phylum Bryophyta

    2. Phylum Hepatophyta

    3. Phylum Anthocerophyta

  • Liverwort Identification:

    • If shown a photo, would you be able to identify it? Look for liver-shaped plants.

  • What are Gemma Cups?

    • Parts found within Phylum Hepatophyta located inside the plant of liverworts.

    • They are small, splash-like cups on the upper surface that aid in asexual reproduction.

  • Hornwort Identification:

    • If shown a photo, would you be able to identify it? Look for distinct features.

  • General Life Cycle of a Plant:

    • Described as an alternation of generations.

Lab 5 - Survey of Seedless Vascular Plants

  • Definition of Xylem:

    • Xylem takes in nutrients for vascular plants and facilitates one-way movement (up).

  • Definition of Phloem:

    • Phloem contains amino acids, sugars, and other organic compounds and allows two-way flow (both ways).

  • Four Phyla Representing Seedless Vascular Plants:

    1. Phylum Lycophyta

    2. Phylum Psilophyta

    3. Phylum Arthrophyta

    4. Phylum Pterophyta

  • Equisetum Identification:

    • If shown a photo, would you be able to identify it? Check slides/paper.

  • Description of Synangia in Psilotum (a whisk fern):

    • Round yellow bumps called synangia that are specialized reproductive structures formed by the fusion of three sporangia, functioning to produce and release spores.

  • Locations of Sori:

    • Sori can be found on the underside of ferns; can you point them out in a photo?

Lab 6 - Survey of Gymnosperms

  • Definition of Homospory:

    • A type of spore production where gametophytes produce both egg and sperm.

  • Definition of Heterospory:

    • Involves two different types of spores.

  • Role of Hygroscopic Elater:

    • Aids in the dispersal of spores by changing shape in response to humidity changes.

  • Identification of Microsporangia and Megasporangia:

    • Can you identify these structures in a Selaginella microscope image? Look on paper/slides.

  • Definition of Gymnosperm:

    • A group of seed-producing plants that bear “naked seeds,” meaning their seeds develop on the exterior.

  • Four Gymnosperm Phyla Discussed:

    1. Phylum Coniferophyta

    2. Phylum Cycadophyta

    3. Phylum Ginkgophyta

    4. Phylum Gnetophyta

  • Gymnosperm Identification:

    • If shown a photo of a gymnosperm discussed in the lab, could you tell the phylum name? Check slides/paper.

  • What is a Conifer?

    • Largely evergreen trees that bear cones.

  • Seed Structure Identification:

    • If shown a dissected seed, would you be able to identify its structures? Check paper/slides.

Lab 7 - Survey of Angiosperms

  • Definition of Angiosperm:

    • Seed plants that differ from gymnosperms as their seeds are enclosed, meaning they are "contained" rather than “naked.”

  • Unique Structures of Angiosperms:

    • Flowers and fruits.

  • Definition of Monocot:

    • A major group of flowering plants distinguished by their single cotyledon in their embryo.

    • Leaf Venation: Parallel venation (straight parallel lines).

    • Vascular Bundles Arrangement: Scattered throughout the ground tissue.

  • Definition of Eudicot:

    • Known as true dicots; they have two seed cotyledons.

    • Leaf Venation: Net-like leaf veins typically in multiples of 4 or 5.

    • Vascular Bundles Arrangement: Arranged in a distinct ring.

  • Identification of Flower Parts:

    • If shown a diagram could you identify the different parts of a flower?

  • Four Whorls in a Flower:

    1. Calyx (sepals)

    2. Corolla (petals)

    3. Androecium (stamens)

    4. Gynoecium (carpels/pistils)

  • Definition of Gynoecium:

    • The innermost, female reproductive whorl of a flower consisting of one or more carpels that produce ovules and develop into fruit seeds.

  • Definition of Androecium:

    • The collective term for all male reproductive organs in a flower, typically forming the whorl inside a petal.

  • Sterile Components of a Flower:

    • Sepals and petals.

  • Infertile Components of a Flower:

    • Same as sterile components: Sepals and petals.

  • Definition of Incomplete Flower:

    • A flower missing at least one of the four whorls.

    • Complete Flower: Consists of all four whorls.

  • Definition of Perfect Flower:

    • A flower that contains both male and female reproductive parts.

    • Imperfect Flower: Contains only one of the sexes.

  • Can a Flower be Incomplete but Perfect?

    • Yes, it can be incomplete yet still possess both male and female reproductive parts.

  • Connation vs. Adnation:

    • Connation: Fusion of similar organs within the same whorl.

    • Adnation: Fusion of dissimilar organs from different whorls.

  • Types of Flower Symmetries:

    • Can you determine symmetry if given a photo?

    1. Radial - multiple symmetry planes.

    2. Bilateral - one symmetry plane.

    3. Asymmetric - no symmetry.

  • Simple, Aggregate, Multiple Fruits - Definitions and Examples:

    • Simple Fruits: Arise from one ovary of a flower (e.g., orange, lemon, tomato).

    • Aggregate Fruits: Arise from multiple ovaries of a single flower (e.g., strawberry, acorns).

    • Multiple Fruits: Result from fused ovaries from many flowers (e.g., pineapple, sunflower).

  • Fleshy vs. Dry Fruits - Definitions and Examples:

    • Fleshy Fruits: Have a soft, succulent, juicy pericarp (e.g., cucumber, orange, olive).

    • Dry Fruits: Have hard, papery, or fibrous pericarp (e.g., strawberry, acorn, sunflower).

  • Fruit Classification Examples:

    • Pineapple: Fleshy, multiple, accessory.

    • Magnolia: Fleshy, aggregate.

    • Strawberry: Dry fruit technically, with external achenes being actual fruits, while the red surrounding tissue is fleshy but from receptacle tissue, thus accessory.

    • Acorn: Dry, simple.

    • Maple: Dry, simple.

    • Tomato: Fleshy, simple.

    • Orange: Fleshy, simple.

    • Lemon: Fleshy, simple.

    • Apple: Fleshy, simple, accessory.

    • Cucumber: Fleshy, simple, accessory.

Lab 8 - Vascular Plant Anatomy and Physiology

  • What is Auxin?

    • A crucial class of plant hormones.

  • What is Apical Dominance?

    • A phenomenon where the main stem of a plant grows more vigorously while inhibiting the lateral buds below it, ensuring vertical growth.

  • Relation of Auxin and Apical Dominance:

    • Auxin enforces apical dominance by suppressing the growth of lower lateral (axillary) buds.

  • What is Leaf Abscission?

    • The natural, active process where leaves shed.

    • Leaf abscission is inhibited by high levels of auxin produced in young, healthy leaves.

  • What Occurs During Pruning?

    • Pruning involves removing specific plant parts - dead, diseased branches to improve structure and health.

    • Benefits include stimulating new growth, increasing fruit/flower production, and improving structural integrity.

  • Identification Exercises:

    • Can you identify a pruned vs. unpruned plant?

    • Can you identify a Helianthus (sunflower) stem cross-section image? Look for key structures: epidermis, pith, cortex, vascular bundles (xylem and phloem).

  • Identification of Leaf Cross Section Images:

    • Ligustrum (privet) and Ranunculus (buttercup).

  • What is Gibberellin?

    • A class of natural plant hormones that regulate growth and development, influencing stem elongation, seed germination, and flowering.

  • Gibberellins and Dwarf Mutant Plants Relation:

    • Gibberellins are essential for promoting stem elongation and cell division. Absence or dysfunction results in dwarfism.

  • Definition of Etiolation:

    • A process where flowering plants grown in partial or total darkness exhibit elongated, weak, pale-yellow stems, small leaves, and elongated internodes.

  • Characteristics of Etiolated vs. Non-etiolated Plants:

    • Non-etiolated plants are compact, green, with sturdy, well-developed stems, and exhibit healthy, proportional leaves.

  • Identification of Etiolated Plants:

    • Can you identify an etiolated pea plant vs. a non-etiolated pea plant image? Check paper/slides.