Day 4

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Plant-like Protists

Phylums of protists

• Euglenophta

• Pyrrophyta

Euglenophytes

• Unicellular aquatic algae – both autotrophic and heterotrophic

• Two flagella with different lengths

• Also called Euglenozoa, Euglenoids, and Euglenophyta

• Heterotrophic

• Charasteristics genus is Euglena

• Swimmers but can change shape

• Can live as saprophytes, organisms that absorb nutrients available in decayed material

Flagella

• Whip-like structure that acts like a cells motor

• Located on the anterior(front)

• Twirls weeeeeeee

• Reservoir

– Inward pocket where flagellum is attached

Chloroplast

• Traps sunlight used for photosynthesis

• Rod-like structures

Eyespot

• Found at the anterior end near the resevoir

• Helps find bright areas to gather sunlight for photosynthesis

• Pellicle – stiff structure that help cell’s shape

• Nucleus – center of the cell that contains the DNA

– Controls the cell’s activities

• Nuleolus– Structure found within the nucleus

• Cytoplasm – jelly-like fluid found in the interior

• Contractile vacuole – star-like structure helps remove excess water to prevent it from exploding

Habitat

• Nutrient-rich freshwater system

• Some in salt waters

• Often abundant in quiet, inland waters where they bloom and color the surface of ponds and ditches green or red

Nutrition

• Heterotrophic – organic compounds

– Osmotrophic – dissolved nutrients

– Phagotrophic – engulfs

• Autotroph – produce own food

– Phototrophic – obtain energy

Reproduction: Asexual

• Mitosis

– Chromosomes in the nucleus are separated, forming two identical sets in two separate nuclei

• Cytokinesis

– Cytoplasm is divided to form two cells

Euglenophyta’s ecology

• Highly eutrophic environments, rich in minerals

• Often found in ponds and ditches near cow pasture, hog lots, chicken farms, etc.

• Thick green or red scum on the surface of the algae bloom

• Often found in water

• Can be used as indicators of polluted areas

Euglena gracilis

• Eat green algae and use it to make food

• Undergoes the process of mitosis

• Reproduce better

• Preys on tiny organisms like amoeba and paramecium

• Harmless to humans, often signs of polluted water

Euglena sanguinea

• Found in red tides

• Has astaxanthin

• Use the pigment to protect chloroplasts from intense light

• May change to green pigment as red pigments move to the center

Dinoflagellates

• Habitat: organisms, fresh water, ocean

• Reproduction: asexual

• Eukaryotes without histones

• Autotrophs, phagotrophs, symbionts, parasites

flagellum

• Propels organism by spinning.

• Wraps around the organism between two thick plates of cellulose

• Has two ______

• Traverse flagellum

• Longitudinal flagellum

Ecology

• Photosynthetic -> primary producers

• Photosynthetic or heterotrophic

• Has symbiotic relationships with some corals

• Eats waste of animals

• Can cause red tide

• Some can produce neurotoxins

• Limiting nutrient number

• Luminescene – luciferases activate luciferinwhich require oxygen

• Gonyaulax & Gymnodinium – produces toxin in red tides

• Notiluce scintillans – phagotrophicdinoflagellate

• Some have endosymbionts

Types of pigments

• Chlorophyll – green

• Carotene – yellow

• Xanthophyll - brown

Chrysophytes and Diatoms• Chrysophytes – golden

• Carotenoids – pigments– Fucoxanthin: yellow-brown

• Stores food as oil

• Very diverse

• Reproductions varies:– Asexual and sexual

• Movement: gliding motion– Has a mucin

– Some travel in colonies

Structure

• Cell wall

– Rigid

– Has pectin or silica

– Some have none: ameboid

• Flagella

– Some have one or two

Acquiring energy

• Facultative heterotrophs

– Can be heterotrophs when there is inadequate amount of light

Plants

Algae

• Live near or in bodies of water

• Has no vascular tissue

• Most are multicellular, some unicellular or colonial

• Reproductive cycles involve alternating sexual and asexual stages

• Well adapted to life in water and intertidal zone

Adaptation to water

• Thin leaf-life structure

• Diffusion of materials through body

• No stems

• Ease of sexual reproduction

Divisions

• Rhodophyta(red algae)

• Phaephyta(brown algae)

• Chlorophyta(green algae)

Rhodophyta

• Pigments: – Chl a(all)

– Phycoerythrin absorbs blue light

– Appears green, pink, red, purple, black

• Food reserve: Floridean starch

• No flagella and centrioles

• Lives in marine but some in freshwater or polar regions

• Mostly multicellular

Phaeophyta

• Pigments:

– Chl a and c

– Fucoxanthin

– Dusky olive/ yellow-brown

• Lives in marine but sometimes in coastal waters

• Food reserve: laminarin

• All multicellular

Chlorophyta

• Pigments: – chl a and b

– Carotenoids

• Food reserve: starch

• Lives in freshwater, marine, moist

• Cell wall – cellulose

• Uni-, multi-, celullar or colonial

• Ancestors of modern plants

Clamydomonas

• 2 flagella

• Cup-shaped chloroplast

• 2 small contractile vacuoles

• Eyespot

• Cell wall not made of cellulose

• Found in ditches

• Gonium

– 4-42 cells living together, funtion independently

• Volvox

– 500-50,000 – arranged in hollow spheres

• Oedogonium

– Thread like colonies

– holdfast cell attached to bottom

– Asexual: broken filaments divide and grow

– Sexual: formation of gametes

reproduction

• Diploid < -> haploid stages

• Asexual <-> sexual modes

• Asexual: spores

• Sexual: gametes

Nonvascular plants

plants

1. Photosynthetic

2. Multicellular eukaryotes

3. Cellulose cell wall

4. Presence of plastid

5. Undergo alternations of generations

– Multicellular diploid and haploid

Terrestrial life

• More sunlight

• More carbon dioxide

• More nutrients

• More minerals

• Less herbivores, pathogens, etc.

Similarities w/ algae

• Alternation of generation

• Needs H2O for reproduction

Lack water conducting tubules

• Osmosis, surface tension

– Only works for short distances

Lack waxy cuticle

• Waxy cuticle -> prevents _____

– Loses H2) easily

Lack true roots

• Rhizoids – root-like structures

– For anchorage

– Does not mainly function as a collector of nutrients

Limited reproduction in a dry environment

• Reproduce when water is available

• Can survive drying periods but it may stop growing.

Similar to modern mosses

• Simple structure

• Stay close to the ground

• Cooksonia

– Simple branched

– Reproductive

– structures

Mosses

• Phylum Bryophyta

– Adapted to wet, low nutrients, low temp

– Habitats: polar regions, tropical

• Gametophyte:

– Stem-like structure: thin upright shoot

– Leaf-like structure:____ cell thick

– No vascular tissues

– No true leaves/ stems

• Sporophyte

– Stalk: holds up capsule

– Capsule: produces spores

– Fully dependent on gametophyte

• w/ rhizoids

Liverworts

• Phylum Hepaticophyta

– Live in constantly wet plaes

Sexual:

• Gametophyte: like flat green leaves on the ground or lobed shaped like a liver

• Sporophyte: tiny umbrella structure

Asexual reproduction

• Gemmae:

– Multicellular spheres w/ many haploid cells

– Divided by mitosis

• Gemma cups

– Cup-like structures that produce gemmae

Hornworts

• Gametophyte: like liverworts’

• Sporophyte: tiny horn like structures

Vascular Plants: Tracheophytes

• Tracheo “wind pipe” or “vascular”

• Xylem(water and minerals)

• Phloem(sugars from leaves)

• Larger and more complex

• Sporophyte is more prominent

• Demonstrate increase levels of ogranization

Primitive vascular plants

Fern Allies

Division Lycophyta: Club mosses• Oldest extant group• Sporangia organized into

strobili• Homosporous /

heterosporous• Contained vascular tissueExample genera:• Lycopodium: bisexual

– Isospores: gametophytes

• Selaginella:– Small – microspore – male– Larger – megaspore - female

Division Sphenophyta: Scouring rushes

• Whorls – leaves produced at nodes

• Isospores

• Spores being elaters

– Gametophyte – small, photosynthetic, free living

• Silica concentrated

• Jointed stems

Division Psilophyta

• Oldest living lineage of vascular plants

• Lack roots

• Stem is photosynthetic

• No leaves but enations not vascular

• Resembles cooksonia

Ferns

Whisk ferns

Lycopods

Horsetails

Ferns

Seed plants

Gymnosperms and Angiosperms

Gymnosperms

Gingkoes

Gnetophytes

Conifers

Cycads

Angiosperms

Monocots

Dicots