Practical bio 300

Prokaryote shape: bacilli

rod shaped

Prokaryote shape: cocci

spherical

prokaryote shape: spirillum

Pleiomorphic bacteria

-lack a cell wall

-varied cell shapes

Gram positive cell wall

thick layer of peptidoglycan

gram negative cell wall

thin peptidoglycan layer

Chemoheterotrophs

An organism that must consume organic molecules for both energy and carbon.

photoheterotroph

An organism that obtains energy from sunlight and carbon from organic sources.

photoautotroph

organism that uses energy from sunlight to convert carbon dioxide and water to carbon compounds

facultative

organism that can survive with or without oxygen

Halobacterium salinarum

•Extreme halophile

•Photoheterotroph

•Bacteriorhodopsin: nonphotosynthetic light-harvesting pigment that can generate ATP

•Consumes amino acids or other organic acids; is therefore heterotrophic

Protists

Any Eukaryote that is not a land plant, animal, or fungus Most are microscopic and unicellular they are Unicellular or multicellular Autotrophic or heterotrophic Asexually or sexually reproducing Sessile or motile, via cilia, flagella, or pseudopodia

Physarum polycephalum

Plasmodial slime mold Moves hydrostatically using pseudopods Feeds and moves primarily through chemotaxis Can change into a resting state conditions sclerotinumin poor Displays complex decision making without a brain: Makes feeding "decisions" based on quality and quantity Remembers where it has been Finds optimal pathways to food sources

Paramecium (Alveolates)

Large, unicellular, heterotrophic, ciliated protist Easy to see nuclear envelope and digestive vacuoles

Biomineralized Protists: Diatoms ( Stramenopiles )

Fresh or saltwater photoautotrophs Tests are made of silicon dioxide, SiO2 glass Each daughter cell receives ½ of the test in mitosis • Diatomaceous earth Powdered diatom fossils Can be taken by mouth for various nutritional uses Also good as an insecticide, scrubbing agent, or toothpaste!

Foraminifera

Supergroup Rhizaria Marine chemoheterotrophs Create calcium carbonate (CaCO3) shells called tests • Tests have elaborate patterns that are species specific Tests create deepsea limestone deposits Pseudopods extend through the tests for feeding and movement

Multicellular Protists: ( Stramenopiles )

Not a fungus, but looks and behaves like one • Multicellular, saprobic or parasitic Body is a mass of cellwide filaments called hyphae Coenocytic: multiple nuclei in one plasma membrane • Similar to Physarum Can reproduce sexually

Unicellular Protists: euglenids

Unicellular and flagellated • Facultative heterotrophs • Can obtain energy heterotrophically or autotrophically

unicellular protsists: Trichonympha

Unicellular and parasitic No mitochondria Endosymbiont of termites • Helps termites digest wood pulp Many family members cause human disease

Multicellular Protists: • Fucus ( Stramenopiles )

Capable of photosynthesis, but is not a plant Brown algae (kelp) Restricted to marine environments Reproduces sexually using gametic meiosis Multicellular specialization Fronds = "leaves" Stipe = "stem" Holdfast = "roots"

green algae

Evolutionarily grouped with land plants; taxonomically grouped with protists Shared characteristics with land plants: • Chlorophylls a and b Cellulosic cell walls Storage of starch in chloroplasts produce 50 •70% of all oxygen in our atmosphere

Chlamydomonas

Chlorophytes Motile, unicellular, freshwater genus of green algae Have both asexual (mitosis) and sexual (gametic meiosis) forms of reproduction

volvox

Motile colonial green algae (chlorophyte) Hundreds to thousands of haploid cells in a gel matrix, Asexual (vegetative) reproduction. Daughter colonies form inside parent colonies, Sexual reproduction Gametes form at end of growing season • Dormant zygotes undergo meiosis before germination

Spirogyra

Freshwater green algae (chlorophyte) Asexual (vegetative) reproduction • Fragmentation of filaments Sexual reproduction • Conjugation

chara

Charophyte considered the most closely related group of green algae to land plants (based on genetic data) • • Freshwater green algae Develop CaCO3 deposits on cell walls, earning them the nickname "stoneworts" • • What other organism develops CaCO3 deposits? What is the general name for this process?

non-vascular land plants

Structures to deal with water scarcity:• Cuticle Stomata Spores, Vascular tissue Sexual reproduction • Increasing efficiency from water All land plants undergo sporic based organisms meiosis aka, alternation of generations Land plants protect the embryo in maternal tissue • Examples: seeds and flowers Photosynthetic efficiency increases in more complex plants

nonvascular simple plants

3 types: • Liverwort ( Hepatophyta Hornwort ( ) Antherophyta • • Mosses, and all of them release spores into the air

liverworts: genus marchantia

Thallus flat mass of tissue, Dominant phase of the life cycle is the haploid gametophyte • Pores on the upper surface allow for gas exchange, Asexual reproduction, Gemma cups Produces clones of the plant Sexual reproduction • Antheridia (male) and archegonia (female) produce sperm and egg, respectively

Liverworts: Antheridia and Archegonia

Produced in disks on stalks Houses male gametes Breaks open to allow sperm to swim away or disperse in raindrops. Produced on the under surface of stalked finger like structures Produces a multicellular sporophyte when eggs are fertilized Sporophyte is attached to and nutritionally dependent on the female gametophyte

mosses

Leafy green non vascular plant, Dominant phase of the life cycle is the haploid gametophyte. • Produces a nonphotosynthetic sporophyte, nutritionally dependent upon the gametophyte Sporophyte forms the sporangium • Specialized diploid organ where meiosis occurs, forming haploid spores

Ceratopteris richardii

Reaches sexual maturity in 2 weeks It secretes a pheromonelike substance ( antheridogen ) which controls the differentiation of male or hermaphroditic sexual forms

seedless vascular plants primary growth

• Primary growth = branching apical growth; responsible for vertical growth • Growth through cell division in mitotic zones called apical meristems located in apices (stem/root tips) of the plant Axillary bud = meristematic tissue laid down by shoot apical meristem at the node between the stem and (eventual) leaf Primary growth gives rise to primary tissues are composed of 3 functional groups: • • • Dermal tissues (epidermis) Vascular tissues (xylem and phloem)stem, roots, and leaves Ground tissues (fill spaces between dermal & vascular -- pith, cortex, mesophyll, parenchyma, sclerenchyma...)

secondary growth and vascular tissues

increases lateral girth in stems and roots; growth comes from the vascular cambium • • • meristem Appears between primary xylem and phloem Generates new vascular tissue • • xylem (wood) grows toward the interior of the stem, phloem grows toward the exterior of the stem

xylem

carries water and dissolved ions upwards to stem & leaves Relies on specialized waterconducting cells, collectively called tracheary elements: • • Vessel elements in angiosperms Tracheids in gymnosperms Cells are dead at maturity & heavily reinforced with lignin, providing structural support

Phloem

carries sugars from leaves downwards to other parts of the plant 2 specialized cell types: • • Sieve elements Companion cells

lycophyte leaves

Microphylls; not anatomically true leaves, though functionally similar derives from protosteleno leaf gap; single vein

Homosporous strobili

Composed of many, densely packed leaves (sporophylls) with attached sporangia

Sporangia contain spores of IDENTICAL size

Shed spores will produce BISEXUAL gametophytes

Heterosporous strobili

MEGASPORANGIA

Produce larger spores (megaspores) that germinate into FEMALE gametophytes

MICROSPORANGIA

Produce smaller spores (microspores) that germinate into MALE gametophytes

Leptosporangiate Ferns

Highly vascularized true leaves (megaphylls) -possess leaf gap •Vascular tissue is arranged in a siphonostele •Possess rhizomes and roots

Fern Leaves

Develop from coiled buds (fiddleheads) May be divided or undivided into one to several levels of pinnae (leaflets) Sporangia are borne on undersurface of fronds or on highly modified, non photosynthetic fronds •Clusters of sporangia = sori (singular sorus) • Indusium (thin protective sheet)

fern life cycle

1). Zygote develops into leafy fern plant. 2) the sporophyte. 3) Spores are released from spore cases and grow into tiny, heart-shaped gametophytes. Each gametophyte has both male and female structures. 4) Sperm swim to another gametophyte to fertilize eggs.

true leaves

Leaf gap Complex vasculature Axillary bud (lateral shoot bud)

Xeromorphic Leaves

Dry environments Designed to prevent water loss • • • Thick cuticle Tight palisade Stomatal crypt • Increases humidity Examples: Nerium (oleander) and Pinus (pine)

Hydromorphic Leaves

Aquatic environment • Leaves either in the water or on the surface of the water So must alter standard architecture for gas exchange • Why? Stomata on upper surface Inside of leaf is filled with water Little structural support • May contain sclereids walls Example: Nymphaeabundles of cells with thick, tough (water lily)

Mesomorphic Leaves

Intermediate environment Standard architecture as seen on slide 4 • Easy to distinguish top from bottom Palisade is on top Most stomata on underside of leaf • Example: Syringa (lilac)

seed-bearing plants

Angiosperms and gymnosperms • Together form a major group of plants called spermatophytes All heterosporous, meaning they possess: Small male microstrobili, Large female megastrobili Spores are retained in sporophyte (2n) parent rather than being cast off to the environment • Spores grow into tiny multicellular gametophytes (n) Parent provides protection and nutrition for fertilized zygote to become new sporophyte (2n)

gymnosperms

Fruitless seed plants •Female gametophytes develop on exterior of sporophyte plant body •No ovary; seeds are unprotected

angiosperm

Flowering plants (>90% of all plants on earth; ~300,000 species) •Major groups: monocots and dicots •Characteristics: •Flower (key) •Fruit (mature ovary) •Double fertilization resulting in 3n endosperm (stores nutrients) and 2n zygote

female pinecone

Each ovuliferous scale contains 2 ovules (megasporangia and integuments) Within the 2n megasporangium is a single meiosis to produce haploid megaspores megasporocyte , which divides by Rest of the cells make up nucellus (2n tissue) of the megasporangium Only one megaspore survives and develops into the megagametophyte (through mitosis)

Pine Archegonia

Two or more (each with an egg) develop within the maturing gametophyte. Mature ovule consists of: Integument Thin layer of remaining nucellus Megagametophyte, containing archegonia with enclosed egg Micropyle = a pore at the end of the ovule • Space between the micropyle and nucellus is the pollination (micropylar) chamber, through which pollen tubes will grow

male pinecone

Two (or more) microsporangia develop on underside of microsporophylls Microsporocytes within microsporangia undergo meiosis to make microspores Through mitosis, microspores develop into immature male gametophytes called pollen grains

moss life cycle

A sporophyte has a specialized capsule that holds the spores which grow into separate male and female gametophytes. Antheridia produce sperm on the male gametophytes and the archegonia produce eggs on the female gametophyte. Antheridium fertilizes the egg of the archegonia which grows into a new sporophyte.

obligate anaerobes

organisms that cannot live where molecular oxygen is present