unit 1 taxonomy protozoa early embryonic development simple metazoans
TRANSCRIPT
![Page 1: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/1.jpg)
ZoologyUnit 1
TaxonomyProtozoa
Early Embryonic DevelopmentSimple Metazoans
![Page 2: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/2.jpg)
Chapter 10 - Taxonomy 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
![Page 3: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/3.jpg)
![Page 4: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/4.jpg)
Taxonomic Ranks 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
![Page 5: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/5.jpg)
Conflicts in Early Taxonomy
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
![Page 6: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/6.jpg)
Modern Taxonomy 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
![Page 7: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/7.jpg)
A new level at the top: Domain
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
![Page 8: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/8.jpg)
![Page 9: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/9.jpg)
Species 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
![Page 10: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/10.jpg)
Biological Species Concept 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=CD6vpheUoPE
![Page 11: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/11.jpg)
Reflecting Ancestry in Taxonomy
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
![Page 12: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/12.jpg)
The Cladistic Approach 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
![Page 13: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/13.jpg)
Sample Cladogram
![Page 14: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/14.jpg)
Create a Cladogram Cladogram #1 moss conifer fern
Chloro-phyte
Angio-sperm
multicellular x x x o x
photosynthetic x x x x xproduces seeds o x o o x
vascular o x x o x
flowering o o o o x
![Page 15: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/15.jpg)
Cladogram Sample #2
Cladogram #2 Bacteria Archaea Protozoa Animals Plants Algae Fungi
DNA x x x x x x x
Autotrophic some some o o x x o
Cell Wall x o o o x x x
Multicellular o o o x x o some
Peptidoglycan x o o o o o o
Nucleus o o x x x x x
![Page 16: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/16.jpg)
Cladogram Sample #3
Cladogram #3Chondrichthyes
Urochordata
Amphibia Reptilia
Mammalia Aves
Osteichthyes
paired limbs o o x x x x o
feathers o o o o o x o
amniote egg o o o x x x o
mammary glands o o o o x o o
vertebrae x o x x x x x
notocord x x x x x x x
bony skeleton o o x x x x x
![Page 17: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/17.jpg)
Kingdom Animalia Eukaryotic Multicellular Heterotrophic No cell wall No
Chloroplasts
![Page 18: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/18.jpg)
Chapter 11 - Protozoa 6. Compare and contrast
protozoans with animals 7. Describe means of locomotion
employed by protozoans 8. Categorize major taxonomic
groups of protozoans
![Page 19: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/19.jpg)
Protozoans = “first animals”
Animal-like protists. Unicellular, but:• Heterotrophic• Lack cell walls (usually)• Motile (usually)
http://www.youtube.com/watch?v=-zsdYOgTbOk&feature=related
![Page 20: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/20.jpg)
Modes of Protozoan Locomotion
Cilia Relatively
short and densely distributed over the surface of the cell
![Page 21: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/21.jpg)
Modes of Protozoan Locomotion
Flagellae Longer and
less numerous than cilia, but practically identical in internal structure
![Page 22: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/22.jpg)
Structure of Cilia & Flagellae
Internal structure consists largely of bundles of microtubules in a “9+2” arrangement
9 pairs in a circular arrangement with 2 in the middle
![Page 23: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/23.jpg)
Cilia and Flagellae http://www.youtube.com/watch?v=Q
GAm6hMysTA
![Page 24: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/24.jpg)
Modes of Protozoan Locomotion
Pseudopodia Literally “false
feet” Extensions of
the cytoplasm used not only for movement but also for feeding
![Page 25: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/25.jpg)
Feeding and Movement of Amoebae
http://www.youtube.com/watch?v=pvOz4V699gk
http://www.youtube.com/watch?v=KeQ1c6_Md1Q
http://www.youtube.com/watch?v=TOPMaNvGTvc
http://www.youtube.com/watch?v=d_Bkg8euB5Y
![Page 26: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/26.jpg)
Modes of Protozoan Locomotion
Non-motile All of these
types are parasitic and rely on a “vector” for movement to a new host
![Page 27: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/27.jpg)
Traditional Protozoan Taxonomy
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
![Page 28: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/28.jpg)
Chapter 12 – Simple Metazoans 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
![Page 29: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/29.jpg)
Metazoans 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
![Page 30: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/30.jpg)
Protozoan Ancestor to Animalia 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
![Page 31: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/31.jpg)
Flagellate Ancestor Hypothesis
Cells called “Choanocytes” in sponges are identical in form and behavior to Choanoflagellate protists, which may be free living or colonial
![Page 32: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/32.jpg)
Multicellularity 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”
![Page 33: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/33.jpg)
Differentiation & Development 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
![Page 34: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/34.jpg)
Early Embryonic Development
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”
![Page 35: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/35.jpg)
Cleavage Patterns and Differentiation
Note that there are 2 different patterns of cleavage, Radial and Spiral
Spiral cleavage results in greater early differentiation of cells
![Page 36: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/36.jpg)
Gastrulation 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
![Page 37: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/37.jpg)
Phylum Mesozoa 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
![Page 38: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/38.jpg)
Phylum Placozoa 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
![Page 39: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/39.jpg)
Phylum Porifera – The Sponges
![Page 40: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/40.jpg)
Phylum Porifera 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
![Page 41: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/41.jpg)
Sponge Anatomy
![Page 42: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/42.jpg)
Canal System Variations
SYCONOIDASCONOID LEUCONOID
![Page 43: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/43.jpg)
Asconoid Sponges The simplest canal system Choanocytes line the spongeocoel
![Page 44: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/44.jpg)
Syconoid Sponges The pouching
of the spongeocoel into radial canals increases the surface area of contact between choanocytes and water flow
![Page 45: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/45.jpg)
Leuconoid Sponges
Incurrent canals direct water into specialized chambers lined with choanocytes
Excurrent canals direct water to the osculum to be expelled
![Page 46: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/46.jpg)
Spongin and Spicules
![Page 47: Unit 1 Taxonomy Protozoa Early Embryonic Development Simple Metazoans](https://reader030.vdocuments.net/reader030/viewer/2022032707/56649e405503460f94b311b4/html5/thumbnails/47.jpg)
Sponge Phylogeny 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