LESSON 5

• Algae


  eukaryotic, unicellular, filamentous, and most are photoautotrophs.
• algae are grouped into several major phyla based on the form of their reproductive cells and combinations of pigments and food reserves.
• phylum chlorophyta - green algae
• phylum chromophyta - yellow-green algae, golden-brown algae,, diatoms, and brown algae
• phylum rhodophyta - red algae
• phylum euglenophyta - euglenoids
• phylum dinophyta - dinoflagellates
• phylum cryptophyta - crytomonads
• phylum prymnesiophyta - haptophytes
• phylum charophyta - stoneworts
• phylum chlorophyta (green algae) occur in a rich variety of forms and in very diverse and widespread habitats.
• green alga (micromonas) which is only 1um and the smallest eukaryotic cell known
• The greatest variety is found in freshwater ponds, lakes and streams. In oceans, they are an important part of the plankton (free-floating, mostly microscopic organisms), and therefore, of food chains.
• Representative green algae include Chlamydomonas, Ulothrix, Spirogyra, Oedogonium and Volvox.
• Phylum Chromophyta is composed of the yellow-green algae, golden-brown algae, diatoms, and brown algae.
• In phylum chromophyta, some members of the first three classes produce a unique resting cell called a statospore. These cells resemble miniature corked bottles.
• Yellow-green algae (Class Xanthophyceae) are mostly freshwater organisms. The two flagella of motile cells are oriented in opposite direction.
• uGolden-brown algae (Class Chrysophyceae) are mostly freshwater plankton. The motile cells have two flagella of unequal length, with a photoreceptor on the short flagellum.
• Diatoms (Class Bacillariophyceae) are mostly unicellular algae that are particularly abundant in colder marine habitats. They look like tiny, ornate, glass boxes with lids. The chloroplasts usually are golden-brown in color because of the dominance of fucoxanthin, the brownish pigment also found in brown algae.
• A major constituent of the foam that accumulates at the wave line on beaches is an oil produced by diatoms.
• Brown algae (Class Phaeophyceae) are relatively large, and none are unicellular or colonial. The color of brown algae can vary from light yellow-brown to almost black, reflecting the presence of varying amounts of the brown pigment fucoxanthin.
• Many of the brown algae have a thallus (multicellular bodies that are usually flattened and not organized into leaves, stems and roots).
• Many brown algae are seaweeds. The giant kelp is the most widely known example of brown algae.
• Phylum Rhodophyta (The Red Algae), are mostly seaweeds that inhabit the warmer and deeper waters.
• The red to purplish colors of most red algae are due to the presence of red and blue accessory pigments called phycobilins.
• Representative red algae include Gigartina, Rhodoglossum, Chondrus, and Polysiphonia.
• Phylum Euglenophyta (The Euglenoids), are commonly found in freshwater and are typically unicellular.
• Euglena cell has no rigid cell wall and can be seen to change shape even the organism moves along. Some species can live in the dark if appropriate food and vitamins are present. A red eyespot, located in the cytoplasm, is associated with light detection.
• Phylum Dinophyta (The Dinoflagellates), are unicellular organisms. The best- known representative of this phylum, the dinoflagellates, are the leading cause of red tide.
• Dinoflagellates are the most common type of  bioluminescent algae that emit bluish to green light. One example is Noctiluca scintillans, also known as the sea sparkle.
• Phylum Cryptophyta (The Cryptomonads), a small group of asymmetrical, somewhat flattened, unicellular, marine and freshwater algae. Each cryptomonad cell has one or more plates on the inside of the plasma membrane.
• Phylum Prymnesiophyta (The Haptophytes), Are mostly unicellular with 2 flagella of similar length. Haptophytes have a third flagellum called haptonema. It is located between the true flagella but does not function in propulsion; instead, it has a sticky tip that aids in food capture.
• Phylum Charophyta (The Stoneworts), Are primarily aquatic organisms that often precipitate calcium salts on their surfaces. They consists of an axis with short, lateral branches in whorls. Some botanists consider them more closely related to mosses than to algae.
• Hyphae- are the individual threads that branch and often fuse together.

  Mycelium- mass of hyphae

  Fruiting body- spore containing structure of fungi
• SEPTATE HYPHAE are fungal mycelia that contain cross walls or septa inside the hyphae
• ASEPTATE HYPHAE are the fungal mycelia that lack septa.
• Phylum Chytridiomycota- the Chytrids
• Phylum Zygomycota- the Coenocytic True Fungi
• The members of Kingdom Fungi are placed in five phyla. Modes of sexual reproduction vary among the phyla and have been important in taxonomic classification.
• Phylum Ascomycota- the Sac Fungi