EUKARYOTES: LICHEN AND ALGAE

Lichens

The partnership in a this is not always mutually beneficial; in some lichens, the fungus produces haustoria that penetrate and kill the photosynthetic member. Such … are maintained only because the phototroph’s cells reproduce faster than the fungus can devour them.

60%

In some lichens, the phototroph releases …of its carbohydrates to the fungus

lichen

The fungus of a … reproduces by spores, which must germinate and develop into hyphae that capture an appropriate alga or cyanobacterium.

soredia

Alternately, wind, rain, and small animals disperse bits of lichen called …, which contain both phototrophs and fungal hyphae, to new locations where they can establish a new lichen if there is suitable substrate.

14,000 species

Scientist have identified over …of lichens. Lichens are abundant throughout the world, particularly in pristine unpolluted habitats, growing on soil, rocks, leaves, tree bark, other lichens, and even backs of tortoises.

Lichens

grow in almost every habitat-from high-elevation alpine tundra to submerged rocks on the ocean’s shores from frozen Antarctic soil to hot desert climes.

Lichens

They do not consistently grow in the dark depths of the oceans and the back world of caves-after all, they require light

Lichens

grow slowly but they can live for hundreds and possibly thousands of years.

fruticose

crustose

foliose

three basic shapes of lichens

fruticose

either errect hanging cylinders

Crustose

grow appresed to their substrates and may extend into the substrate for several millimeters

Foliose

leaf-like with margins that grow free from substrate.

Lichens

important agents in creation of soil from weathered rocks

Lichens

containing nitrogen-fixing cyanobacteria provide nitrogen to nutrient-poor environments

reindeer and caribou

many animals eat lichens, for example, …subsists primarily on lichens throughout the winter

birds

use lichens for nesting materials, and some insects camouflage themselves with bits of living lichens

Lichens

humans also used this in the production of food, dyes, clothing, perfumes, medicines, and the litmus indicator paper. Because they will not grow well in polluted environments, ecologists use them as sensitive living assays for monitoring air pollution

chlorophyta

green algae

chlorophyta

Chlorophylls a and b, carotene, xanthophylls

chlorophyta

sugar, starch

chlorophyta

crysophyta

phaeophyta

pyrrophyta

their cell walls contains cellulose

chlorophyta

euglenophyta

their habitat is fresh, brackish, and saltwater terrestrial

chlorophyta

Spirogyra

Prototheca

Codium

Trebouxia

Rhodophyta

chlorophyll a, phycoerythrin, phycocyanin, xanthophylls

rhodophyta

red algae

rhodophyta

storage product is glycogen (floridean starch)

rhodophyta

cell wall is agar, carrageenan

rhodophyta

habitat is mostly water

chrysophyta

golden algae, yellow-green algae, diatoms

chrysophyta

Chlorophylls a, C1 and c2; carotene, xanthophylls

chrysophyta

storage product is chrysolaminarin

chrysophyta

their habitat is fresh, brackish,and salt water, terrestrial; ice

chrysophyta

Navicula

phaeophyta

brown algae

phaeophyta

Chlorophylls a and c xanthophylls

phaeophyta

storage product is laminarin oils

phaeophyta

their cell wall is cellulose and alginic acid

phaeophyta

Brackish and salt water

phaeophyta

Macrocystis

pyrrhophyta

dinoflagellates

pyrrhophyta

Chlorophylls a; Cq and C2 carotene

pyrrhophyta

storage product is starch, oils

pyrrhophyta

their habitat is fresh, brackish and salt water

pyrrhophyta

gymnodinium, gonyaulax, pfiesteria

euglenoids

Chlorophylls a and b, carotene

euglenophyta

their storage products is paramylon,oils, sugar

euglenophyta

their habitat is absent

alga

The Romans used the word … to refer to any simple aquatic plant, particularly one found in marine habitats.

algae

properly refers to simple, eukaryotic, photosynthetic organisms that, like plants, carry out oxygenic photosynthesis using chlorophyll a

algae

differ from plants such as sea grass in having sexual reproductive structures in which every cell becomes a gamete

algae

In plants by contrast, portion of the reproductive structure always remains vegetative

algae

Even though some … grow in such diverse habitats as in soil and ice, in intimate association with fungi as lichens, and on plants; most of these are aquatic, living in the photic zone (penetrated by sunlight) of fresh, brackish and salt bodies of water.

chlorophyll a

captures red light; water absorbs longer wavelengths of light (including red light), so only shorter (blue) wavelengths penetrate more than a hundred meter below the surface. This is problematic for algae because they capture red light

accessory photosynthetic pigments

Thus, to grow in deeper waters, algae must have … that trap the energy of penetrating, short-wavelength light and pass that energy to chlorophyll a.

red algae

Members of the group of algae that contain phycoerythrin , a red pigment that absorbs blue light, enabling red algae to inhabit even the deepest parts of the photic zone.

phycoerythrin

a red pigment that absorbs blue light, enabling red algae to inhabit even the deepest parts of the photic zone.

algae

can be unicellular or colonial, or they can have simple multicellular bodies called thalli, which are commonly composed of branched filaments or shee

seaweeds

The thalli of large marine algae, commonly called … can be relatively complex, with branched holdfast to anchor them to rocks, stem-like stipes, and leaf-like blades.

pneumocysts

The thalli of many of the larger marine algae are buoyed in the water by gas-filled bulbs called

thalli

the … of some marine algae can surpass land plants in length, the lack well-developed transport systems common to vascular plants.

red alga

microcladia

unicellular algae asexual reproduction

involves mitosis followed by cytokinesis

multicellular algae

may reproduce asexually by fragmentation, in which each piece of a parent alga develops into a new individual, or by motile or non-motile asexual spores.

gamete

in multicellular algae that reproduce sexually, every cell in the reproductive structures of the alga becomes a …-a feature that distinguishes algae from all other photosynthetic eukaryotes.

unicellular algae sexual production

each algal cell acts as a gamete and fuses with another such gamete to form a zygote, which then undergoes meiosis to return to haploid state

multicellular algae

reproduce sexually with an alteration of generations of haploid and diploid individuals.

diploid individuals

undergo meiosis to produce male and female haploid spores that develop into haploid male and female thalli, which may look identical to the diploid thallus

zygote

some algae, each of these thalli produces gametes that fuse to form a … which grows into a new diploid thallus.

asexually

Both haploid and diploid thalli may reproduce … as well.

(1) Photosynthetic pigments

(2) Storage products

(3) Cell wall composition

classification of algae is not yet settled. Historically, taxonomists have used differences in:

green algae

18S rRNA sequences of this and plants are comparable. Because of its similarities, …are often considered to be progenitors of plants, and in some taxonomic schemes the Chlorophyta are placed in the Kingdom Plantae.

green algae

are unicellular of filamentous and live in freshwater ponds, lakes, ad pools, where they form green to yellow scum.

intertidal zone

Some multicellular forms grow in the marine …that is, in the region exposed to air during low tide.

prototheca

is an unusual green algae in that in lacks pigments making it colorless. This chemoheterotrophic alga causes a skin rash in sensitive individual

codium

is a member of a group of marine green algae that do not form cross walls after mitosis; thus, the entire thallus is a single, large, multinucleate cell. Some Polynesians dry and grind Codium for use as seasoning pepper.

rhodophyta

Placed historically in Kingdom Plantae and then Protista, are now in their own kingdom- …. They are characterized by the red accessory pigment phycoerythrin ; its cell wall is sometimes supplemented with calcium carbonate; and non-motile male gametes called spermatia .

phycoerythrin

allows red algae to absorb short wavelength blue light and photosynthesize at depths greater than 100 meters.

green to black

Because relative proportions of phycoerythrin and chlorophyll a vary, red algae range in color from …in the intertidal zone to red in deeper water. Most red algae are marine, though a few freshwater genera are known

agar and carrageenan

The gel-like polysaccharides …, once they have been isolated from red algae such as Gelidium and Chondrous, are used as thickening agents for the production of solid microbiological media , and numerous consumer products, including ice cream, toothpaste, syrup, salad dressings, and snack foods.

kingdom Stramenophila

The brown algae are in …based in large part on their gametes being motile by means of two flagella-one “hairy” and one whiplike.

brown algae

They have chlorophyll an and c, carotene, and brown pigments called xanthophylls .

dark brown, tan, yellow-brown, greenish brown, or green.

Depending on the relative amount of their pigments, brown algae may appear

Macrocyctis

Most brown algae are marine organisms, and some of the giant kelps, such as …, rival the tallest trees in length, though not in girth.

Fucus

The two types of flagella of the sperm of the brown alga,

pneumocysts

The giant kelp Macrocytis, a brown alga. A kelp’s blades are kept afloat by

chrysophyta

is a group of algae that are diverse with respect to cell wall composition and pigments. They are unified in using the polysaccharide chrysolaminarin as a storage product. Some additionally store oils.

chrysophyta

Modern taxonomists group these algae with brown algae and water molds in the kingdom Stramenopila based on similarities in nucleotide sequence and flagellar structure.

scales or plates

Whereas some Chrysophytes lack cell walls, others have ornate external coverings such as

chrysophytes

are unicellular or colonial. All of this contain more orange- colored carotene pigment than they do chlorophyll, which accounts for the common names of two major classes of …-golden algae and yellow green algae.

diatoms

are major component of marine phytoplankton; free floating photosynthetic microorganisms that form the basis of food chains in the oceans. Further, because of their enormous number, they are the major source of the world’s oxygen.

diatomaceous earth

Organic farmers used …, composed of innumerable frustules of dead diatoms, as pesticides against harmful insects and worms.

diatomaceous earth

is also used in polishing compounds, detergents, paint removers, and as a component of firebrick, soundproofing products, swimming pool filters, and reflective paints.

Water Molds

Have cellulose in their cells walls while fungi have chitin

oomycota

water molds

water molds

better known as the mildews

fish tank fuzz

example of water molds

water molds

protist- like mold because share common characteristics with plant- like protists, such as the cell wall

water molds

are not true molds; they are not fungi.

water molds

They have tubular cristae in their mitochondria.