Algal Biology Exam 1: Set 1

Euglenoids

A small group mainly freshwater; typically grass green; extremely abundant in nutrient-enriched polluted waters such as farm pans and ditches.

Algae Negatives

Algal blooms can damage aquatic environments by depleting oxygen and interfering with water purification; some algae can also produce toxins resulting in massive fish kills and even human deaths.

Three most Prominent Lines

Chromista (Brown algae), the red algae, the green algae.

Brown Algae Life Cycle

Conspicuous phase usually diploid; in some there is an alternation of generations; in others Fucus or Rockweed, there is no free-living haploid.

Spirulina

Corkscrew shaped algae, significant quantities of proteins, vitamins and minerals; sold in the US as a health food; Ancient Aztecs cultivated mats of spirulina in shallow ponds and lakes; traditional meal in parts of Chad; considered to be one of the solutions for malnourishment in developing countries.

Pennate

Diatom shape, elongate with bilateral symmetry

Centric

Diatom shape, round with radial symmetry

Kingdom Protista (Domain Eukarya)

Dionphyta (dinoflagellates); Bacillariophyta (diatoms); Euglenophyta (euglenoids); Chlorophyta (green algae); Rhodophyta (red algae); Phaeophyta (brown algae).

Green Algae

Division Chlorphyta, great many morphological types, found in oceans fresh water and in moist terrestrial environments, several form symbiotic relationships with fungi to make up lichens, along with red and brown algae some of the larger marine species of green algae referred to as seaweeds. Occurs in unicellular, colonial and filamentous forms.

Frustule

Glasslike wall in diatoms, intricately marked with pits grooves and ridges, microscopically look like cut glass.

Brown Algae

Include the huge kelps; form underwater forests off the california coast, rockweeds found in intertidal zones, some species of kelp are the largest organisms on Earth (reach 100 meters in length); most structurally complex of the algae.

Domain Bacteria

Includes prokaryotic organisms and cyanobacteria (blue-green algae).

Euglenids

Independent line of single-celled organisms include both photosynthetic and non-photosynthetic species.

Manna

Irsaelites consumed on their 40-7ear sojourn in the desert may have been blue-green algae known as Nostoc

Green Algae Continued

MOst abundant and diverse in fresh water, play key role in aquatic food chains, seasonal blooms noticeable in ponds and lakes, DNA analysis indicates that they all evolved from the same ancestor which is a freshwater green algae.

Red Algae Life Cycle

Mainly have three stages, two diploid and one haploid; differ from other eukaryotic algae in that they have no flagellated cells.

Diatoms

Mainly unicells surrounded by a silicon-based wall; two halves fit together like top and bottom of a box; used in detergents, paint removers, and toothpaste.

Cyanobacteria Structure

Microscopic unicells, filamentus, colonial forms, usually bluish green, no chloroplasts because they are prokaryotes, photosynthetic pigments occur on membranes distributed within the cytoplasm; reproduction consists of cell division and fragmentation of filamentous forms.

Cyanobacteria Specifics

Molecular evidence suggests that certain blue-green algae are progenitors of chloroplasts of some higher algae and plants which confirms the Endosymbiont Theory; Some species sold as beneficial dietary supplement; Have caused environmental problems in algal blooms and eutrophication.

Phycocyanin

Most abundant phycobillin in cyanobacteria

Red Algae

Most familiar as seaweeds; mainly large multicellular marine forms occurring in coastal waterways and attached to rocks; most diverse in warm tropical waters at depths of 250 meters; color mainly due to phycoerthrin; multicellular thallus the base of which is modified into a holdfast; this is the algae used as food and food additives.

Algae

Most simplest and abundant form of plant life; responsible for more than half of the world's primary production of oxygen; occupy the base of the food chains in both freshwater and marine ecosystems; used for food for humans and livestock (particularly seaweeds); supply additives in food and cosmetics; used to produce biofuels.

Heterocysts

Nitrogen Fixation result in cyanobacteria from air and water in these specialized cells.

Classification of Algae General

Once considered most primitive members of the plant family; today classified into two separate kingdoms; molecular evidence suggests algae represent several independent evolutionary lines; green algae are the ancestors of all green plants; 28,500 species of algae are known and are classified into 10 divisions

Phycoerthrin

One of the most important phycobillins in cyanobacteria; provides distinct coloration.

Phycobillins

Photosynthetic pigments that capture light; found in red algae and cyanobacteria.

The Green Line

Related to plants. Plants and green algae contain chlorophylls a and b. Most complex forms are found among the green algae; this lineage eventually led to the higher land plants; point where non-algal plants begin and algae stop is usually taken to be the presence of reproductive organs and protective cell layers a characteristic not found in other algal groups.

Dinoflagellates

These evolved on a separate line that includes ciliated protists. Unicells; abundant in fresh water and oceans; along with diatoms are important components of food chain; many covered with cellulose plates (armored appearance); typically possess two flagella (one tailing, one wrapped around the middle, enable them to roll through the water like a top); some marine species responsible for 'red tides'; others known for their ability bioluminesce; generally reproduce by simple cell division, sexual reproduction does occur among some species.

Chromista

This line includes the brown algae, golden brown algae, and diatoms; the plastids in these algae contain chlorphylls a and c.

Cyanobacteria General

Traditionally known as blue-green algae. Prokaryotic; many phycologists study Cyanobacteria and Eukaryotic algae; first appear in fossil records 3.5 billion years ago; today are widely distributed in oceans, fresh water, damp terrestrial habitats, alkaline hot springs, slimy scum on greenhouse floor, pool decks, etc.

Porphyra

Used more extensively and by more cultures than any other seaweed, dates back to A.D 533; most widely cultivated and known by many names. Health risks: rotting seaweed is a potent source of hydrogen sulfide, a highly toxic gas. Been implicated in some incidents of apparent hydrogen-sulphide poisoning. Can cause vomiting and diarrhea.

The Red Line

red algae can often be seen coating wave washed rocks; a characteristic of red algae is that their plastids contain only one type of chlorphyll, chlorophyll a. This is different from green algae and plants which have both chlorphyll a and b.