1. Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans

2.  1.List the hierarchy of taxonomic ranks in the modern classification system  2.Compare & contrast concepts of species identification  3.Explain how taxonomic characters are used to infer evolutionary relationships  4.Define “clade”. Use shared and derived characters to construct cladograms  5.Identify characteristics that define the Animal Kingdom

4.  Taxonomic groupings are of human design, and are organized in a way to simplify our thinking about living organisms  Early taxonomic systems recognized two Kingdoms, Plant and Animal  As more varied organisms have been discovered, many do not neatly fit into either the Plant or Animal Kingdom

5.  Fungi have cell walls and are sessile, but cannot make their own food  Many single celled organisms are capable of photosynthesis, but have well developed mechanisms for locomotion  Cyanobacteria (formerly known as Cyanophyta) are photosynthetic, but lack organelles and a true nucleus

6.  Taxonomic systems expanded from the early 2 kingdom approach to the recognition of 5 kingdoms: Monera (the bacteria), Protista, Fungi, Plantae, and Animalia  Improvements in analytical techniques have uncovered significant differences in bacteria resulting in the recognition of 2 distinct types, Archaebacteria and Eubacteria

7.  Modern trends in taxonomy emphasize ancestral relationships over convenience. The addition of Domain above the Kingdom level allows grouping of related Kingdoms. There are 3 recognized Domains: Archaea – Includes the Kingdom Archaebacteria Eubacteria – The “true Bacteria” Eukarya – Eukaryotes:  Includes Kingdom Protista, Fungi, Plantae and Animalia

9.  There are different approaches to the recognition of species. Each approach has advantages and disadvantages Morphological Species Concept  Based on body form characteristics Biological Species Concept  Based on the ability to interbreed Evolutionary and Phylogenetic Species Concepts  Based on ancestral/evolutionary relationships

10.  Based on the ability to interbreed  Some closely related species can interbreed, but their offspring are sterile (example: lion x tiger = liger)  http://www.youtube.com/watch?v=CD6v pheUoPE http://www.youtube.com/watch?v=CD6v pheUoPE

11.  Accurate interpretations of evolutionary relationships require a variety of evidence. The difficulty lies in determining which similarities are superficial and which reflect common ancestry “Homology” reflects common ancestry “Analogous” traits are evolved independently in separate lineages

12.  Modern taxonomy is moving towards greater emphasis on common ancestry  Cladistics is based on identifying an ancestral characteristic present in a lineage  Progressively smaller groupings are formed as the result of “derived” characteristics  A “clade” includes all descendants of a particular ancestral lineage

14. Cladogram #1mossconiferfern Chloro- phyte Angio- sperm multicellularxxxox photosyntheticxxxxx produces seedsoxoox vascularoxxox floweringoooox

15. Cladogram #2BacteriaArchaeaProtozoaAnimalsPlantsAlgaeFungi DNAxxxxxxx Autotrophicsome ooxxo Cell Wallxoooxxx Multicellularoooxxosome Peptidoglycanxoooooo Nucleusooxxxxx

16. Cladogram #3 Chondrichthyes Urochordata Amphibia Reptilia Mammalia Aves Osteichthyes paired limbsooxxxxo feathersoooooxo amniote eggoooxxxo mammary glandsooooxoo vertebraexoxxxxx notocordxxxxxxx bony skeletonooxxxxx

17.  Eukaryotic  Multicellular  Heterotrophic  No cell wall  No Chloroplasts

18.  6.Compare and contrast protozoans with animals  7.Describe means of locomotion employed by protozoans  8.Categorize major taxonomic groups of protozoans

19.  Animal-like protists. Unicellular, but: Heterotrophic Lack cell walls (usually) Motile (usually)  http://www.youtube.com/watch?v=- zsdYOgTbOk&feature=related http://www.youtube.com/watch?v=- zsdYOgTbOk&feature=related

20.  Cilia  Relatively short and densely distributed over the surface of the cell

21.  Flagellae  Longer and less numerous than cilia, but practically identical in internal structure

22.  Internal structure consists largely of bundles of microtubules in a “9+2” arrangement  9 pairs in a circular arrangement with 2 in the middle

23.  http://www.youtube.com/watch?v=QGA m6hMysTA http://www.youtube.com/watch?v=QGA m6hMysTA

24.  Pseudopodia  Literally “false feet”  Extensions of the cytoplasm used not only for movement but also for feeding

25.  http://www.youtube.com/watch?v=pvOz 4V699gk http://www.youtube.com/watch?v=pvOz 4V699gk  http://www.youtube.com/watch?v=KeQ1 c6_Md1Q http://www.youtube.com/watch?v=KeQ1 c6_Md1Q  http://www.youtube.com/watch?v=TOPM aNvGTvc http://www.youtube.com/watch?v=TOPM aNvGTvc  http://www.youtube.com/watch?v=d_Bk g8euB5Y http://www.youtube.com/watch?v=d_Bk g8euB5Y

26.  Non-motile  All of these types are parasitic and rely on a “vector” for movement to a new host

27.  Since motility is a trait generally associated with Animals, categorizing the protozoa by their locomotion was a logical approach:  Flagellates – use flagellae  Ciliates – use cilia  Sarcodines – use pseudopodia  Sporozoans – are nonmotile

28.  9.Discuss the colonial flagellate hypothesis of metazoan origin  10.Identify distinguishing characteristics of the phylum mesozoa  11.Identify distinguishing characteristics of the phylum placozoa  12.Identify distinguishing characteristics of the phylum porifera  13.Discuss the fundamental anatomy of sponges  14.Relate variations in sponge canal systems to feeding efficiency  15.Categorize the classes of sponges

29.  Metazoans, in contrast with Protozoans, are truly multicellular (with some differentiation of tissues)  The most “primitive” of the metazoa are barely more than colonies of cells, but have some cells specialized for feeding, or reproduction, or locomotion

30.  2 hypotheses have been advanced as to the protozoan ancestor to the animals: Amoeboid ancestor Flagellate ancestor  Cells resembling each of these protozoan forms exist in some form within the Animal kingdom  The more accepted hypothesis is the Flagellate ancestor hypothesis

31. Cells called “Choanocytes” in sponges are identical in form and behavior to Choanoflagellate protists, which may be free living or colonial

32.  Multicellular organisms differ from colonial organisms due to the specialization of cells and the division of labor that results.  Groups of cells that are structurally and functionally specialized are “tissues”  Tissues that combine together for related functions are “organs”  Organs that perform a broad coordinated function form a “system”

33.  All animals share a common pattern of embryonic development (suggesting a common ancestry)  Much of the phylogeny of Kingdom Animalia can be traced back to variations in early embryonic development  Animal phyla generally considered “primitive” only go through a few stages of development, while the more “complex” phyla go through additional stages

34.  The zygote divides in two (“cleavage”), then 4, then 8, forming a raspberry shaped “morula”  Cleavage continues forming a hollow ball of cells called a “blastula”

35.  Note that there are 2 different patterns of cleavage, Radial and Spiral  Spiral cleavage results in greater early differentiation of cells

36.  The blastula caves in on one end, forming an inner layer (endoderm) and an outer layer (ectoderm)  The resulting space (“Archenteron”) will form the digestive cavity

37.  Mesozoa are basically an elongated Morula – They never reach the Blastula stage  Mesozoans are at the “cellular level” of organization. No true tissues exist  The inner layer of cells are specialized for reproduction  All known forms are parasitic

38.  The body form of placozoans is a flattened Blastula  Placozoa are also at the cellular level of organization  The “oral” surface is specialized for feeding and locomotion

40.  The name Porifera is derived from many pores (ostia) that allow water to flow through the channels in the body wall, allowing the sponge to filter feed  The flow of water is driven by flagellated “choanocytes” lining the channels

42. SYCONOID ASCONOIDLEUCONOID

43.  The simplest canal system  Choanocytes line the spongeocoel

44.  The pouching of the spongeocoel into radial canals increases the surface area of contact between choanocytes and water flow

45.  Incurrent canals direct water into specialized chambers lined with choanocytes  Excurrent canals direct water to the osculum to be expelled

47.  Phylum Porifera is divided into 3 classes  Class Calcarea Calcium carbonate spicules All 3 canal system types represented  Class Hexactinellidae 6 rayed, siliceous spicules Syconoid or Leuconoid canal systems  Class Demospongiae Siliceous spicules (not 6 rayed), spongin Leuconoid canal systems