Miscellaneous Eukarya

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Plasmodial Slime Molds

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Organisms consisting of a multinucleated ameboid mass of cytoplasm called a plasmodium that engulf food by phagocytosis. In adverse conditions converts themselves into sporangia with spores where meiosis occurs.

 

 

Phylum:Oomycota

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Members with a body consisting of coenocytic hyphae. These are either saprophytic or parasitic and digest food extracellularly. Because of these characteristics they have historically been considered a fungus. They are now excluded from the kingdom, Fungi, because of the presence of flagella in their zoospores, by their cell wall composition (cellulose or cellulose-like compounds, not chitin), and by their non fungus-like life cycle. These are essentially diploid organisms with gametic meiosis.

Know to Genus

Saprolegnia

Be able to recognize zoosporangia, oogonia, antheridia, eggs, and zygotes

Movies

Phylum: Bacillariophyta (Diatoms)

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Eukaryotic, photosynthetic organisms with chlorophylls a and c. Mostly unicellular though some form filaments and loose colonial aggregations. Their walls are made of silicon and consist of two parts that connect together like a pill box. The face-view of a cell encompassing an entire part is a valve-view, a view showing where these parts overlap is a girdle-view. These organisms are the most important primary producers in the world's waters.

 

Pennate diatoms

Are bilaterally symmetrical in valve-view. Many are motile when in contact with a substrate, and live in sediments, on rocks ect. and, hence, are important primary producers in shallow waters.

Centric diatoms

Are radially symmetrical in valve-view. Are typically part of the planktonic community, hence, are important producers in deep waters such as ocean environments.

Movies


Phaeophyta - The Brown Algae

Photosynthetic organisms with chlorophylls a and c. Members are distinct from other such groups as determined by their cell ultrastructure and complexity of their body structure. This group includes members that have a higher level of tissue differentiation than any other protist. Some kelps form sieve-tube members able to transport photosynthate. In general, kelps also have a rather complex external morphology which can be divided into three features: the blade, a holdfast and the stipe. Primarily a marine group.

Recognize to Genus

Fucus

Know conceptacles, receptacles, oogonia and antheridia, and be able to answer questions demonstrating an understanding of its life cycle.

Know by Common Name

Kelps

Recognize blade, holdfast and stipe.for any kelp seen in lab

Other Examples of brown algae

Sargassum

Etable Kelp Kombu and Wakame

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Division: Chlorophyta

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Of all the phyla in the kingdom Protista, this is the one which is most directly relevant to botanists. This is because plants are believed to have evolved from the green algae. There are several lines of evidence that lead us to this conclusion:

1. Green algae have the same photosynthetic pigments as plants (Chlorophylls a & b)

2. They store their food as starch in plastids (chloroplasts) - unlike plants (except hornworts!) starch deposition is associated with a structure called a pyrenoid.

3. Some have cell walls composed of cellulose.

4. One class of the Chlorophyta, the Charaphycean green algae, undergoes cytokinesis, like plants, through the creation of a cell plate mediated by a phragmoplast.

You need to know the following nine examples, by genus phylum and kingdom.

Chlamydomonas

Volvox

Ulva

You need to know the following nine examples, by genus (except desmids), class, phylum and kingdom.

Class Charophyceae- Cell division associated with a phragmoplast (see text p. 280)

Spirogyra

Chara

Coleochaete

 

Other Examples of Green Algae:


Class: Chlorophyceae - Cell division associated with a phycoplast:
Eremosphaera

Hydrodictyon
Oedogonium


Class: Ulvophyceae - Cell division not associated with a phycoplast or a phragmoplast. Mitosis occurs without the breakdown of the nuclear envelop.


Cladophora


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