BIOA01H3 Lecture Notes - Lecture 10: Heterokont, Pseudopodia, Lichen

• School: UTSC
• Department: Biological Sciences
• Course: BIOA01H3
• Professor: Mark Fitzpatrick

Document Summary

Evolution eukaryotic cells origins & diversity. Protists: protists likely evolved about 1. 5 2 billion years ago, protists are paraphyletic. Unlike prokaryotes, protists have: a membrane-bound nucleus, with multiple, linear chromosomes, there are cytoplasmic organelles, such as er and golgi, including mitochondria and chloroplasts in some species, transcription and translation characteristics are similar to other eukaryotes. Protist diversity: habitat: aqueous, aquatic or moist terrestrial locations, oceans, freshwater lakes, ponds, streams, and moist soil and within host organisms, structure: unicellular or colonies with little differentiation, some colonies are large multicellular organisms, such as giant kelp. Intracellular protist structures: contractile vacuole: pumps water to prevent lysis in freshwater, pellicle: layer of supportive protein fibers under plasma membrane, pseudopodia: lobes of cytoplasm for amoeboid movement. Opisthokonta: have a single posterior flagellum at some stages in the life cycle: choanoflagellata (choanoglagellates), collar of microvilli surrounds single flagellum, likely ancestor of fungi and animals.