Originally, there were two subsections in the Protist (a/k/a Protoctista) kingdom: the Phylum_Protozoa (the animal-like protists) and the Division_Algae (the plant-like protists). Both groups were previously members of the animal and plant kingdoms, respectively. When you study zoology and botany, these groups will be included in the review of the animal and plant kingdoms. Since the early days of the Protist kingdom in the 1800’s a few more groups have been added to the kingdom, including the fungus-like (slime_molds and water_molds) protists.
The Protozoa ("first animals") are the animal-like (heterotrophic, motile) Protists and are classified (in part) based upon their method of motility (such as cilia, pseudopods, and flagella). Representatives of this group are primarily unicellular or colonial.
Use pages 18-23 and 32-38 in the Photo Atlas as a reference for your review of the Protists. Recall that the authors of your Photo Atlas do not use the same exact method of classification as the authors of your textbook. Hence, the water molds and most algae are placed in the Protist group by your text authors, but not the Photo Atlas authors.
The plant-like Protists are called algae. The main characteristics of algae include that they are aquatic, they range in size from unicellular to multicellular and they are photosynthetic. These organisms account for at least half of all photosynthetic organisms on Earth. One of the reasons they are not considered true plants is because they lack a waxy_cuticle. Another reason is that the algae have chlorophyll-A like the true plants, but differ in terms of other pigments. These organisms are ecologically important not just because of photosynthesis, but also because they are used either as food or in the preparation of some forms of food. The basis of their classification includes (1) type of pigment(s) and (2) type of storage product(s).
Vaucheria belongs to the Chrysophyta (golden-brown_algae). Most members of the Chrysophyta are unicellular, but some are colonial. They have two flagella as well as tiny scales made of silicon or calcium_carbonate. Their pigments include chlorophylls a and c, carotenoids and fucoxanthin. Their storage product is a type of oil.
This organism has long tubular body cells, each containing a large central vacuole and thousands of nuclei. Vaucheria can reproduce asexually or sexually. Sexual reproduction involves the formation of male (antheridia) and female (oogonia) structures. Sperm are released from the antheridia and fertilize the single egg located in each oogonium.