Animal Kingdom: Characteristics, Body Plans, and Phylums, Slides of Biology

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Invertebrates Chapter 33 Animal Origins BACTERIA ARCHAEA EUKARYA fungi plants | A great diversity of body plans occur; some key features include: Organized federation of cells vs. cells in tissues Characteristics of the Animal Kingdom Tissue – integrated group of cells with a common structure and function Tissues are generally further integrated into organs Organs are generally further integrated into organ systems A great diversity of body plans occur; some key features include: For organisms with tissues: two vs. three principal embryonic tissues Characteristics of the Animal Kingdom Two embryonic tissue layers: Characteristics of the Animal Kingdom Fig. 32.2 Zygote Blastula Gastrulatio n Gastrula Blastocoel Blastocoel Endoderm Ectoderm Blastopore Archenteron Characteristics of the Animal Kingdom A great diversity of body plans occur; some key features include: Radial vs. bilateral symmetry Any plane that passes through the central axis produces roughly mirror-image halves A single midline plane produces roughly mirror-image halves; generally accompanied by distinct cephalization Fig. 32.7 Among organisms with 3 germ layers: Acoelomate, pseudocoelomate, or coelomate Characteristics of the Animal Kingdom A great diversity of body plans occur; some key features include: Among organisms with 3 germ layers: Acoelomate, pseudocoelomate, or coelomate Characteristics of the Animal Kingdom A great diversity of body plans occur; some key features include: Acoelomate: lack a coelom, i.e., lack a body cavity between digestive track and body wall Fig. 32.8 Characteristics of the Animal Kingdom A great diversity of body plans occur; some key features include: Protostome vs. deuterostome development Characteristics of the Animal Kingdom A great diversity of body plans occur; some key features include: Protostome vs. deuterostome development See Fig. 32.9 The Animal Kingdom ~ 35 phyla C a lc a re a S il ic a re a C te n o p h o ra C n id a ri a E c h in o d e rm a ta C h o rd a ta B ra c h io p o d a P h o ro n id a E c to p ro c ta P la ty h e lm in th e s N e m e rt e a M o ll u s c a A n n e li d a R o ti fe ra N e m a to d a A rt h ro p o d a “Radiata” “Porifera” Deuterostomia Lophotrochozoa Ecdysozoa Bilateria Eumetazoa Metazoa Ancestral colonial flagellate Fig. 32.11 & Table 33.7 Organized aggregation of cells Three main cell types, but no true tissues Asymmetric body plan Mostly marine, but some inhabit fresh water Phylum Porifera – Sponges Internal skeleton of protein spicules E.g., natural bath sponge Phylum Porifera – Sponges Eumetazoa All animals except sponges belong to the clade Eumetazoa All eumetazoans have true tissues Ancestral colonial choanoflagellate Eumetazoa Bilateria Deuterostomia P o ri fe ra C n id a ri a O th e r b ila te ri a n s ( in c lu d in g N e m a to d a , A rt h ro p o d a , M o llu s c a , a n d A n n e lid a ) E c h in o d e rm a ta C h o rd a ta Figure 33.2 Polyp and medusa forms Fig. 33.5 Phylum Cnidaria – Corals, Jellyfish, Anemones Polyp and medusa forms Phylum Cnidaria – Corals, Jellyfish, Anemones Phylum Ctenophora – Comb jellies 8 rows of comblike plates of cilia — s =) P. Platyhelminth Flat worms Mostly free-living Mostly free-living P. Platyhelminthes – Flat worms Some parasitic E.g., tapeworms Distinguishing feature is a “crown of cilia” around the mouth P. Rotifera – Rotifers Complete digestive tract surrounded by pseudocoelom Parthenogenesis (development from unfertilized eggs) is the most common mode of reproduction P. Phoronida A group of tube-dwelling marine worms Mesocoel Protocoel _ + Nerve _ Mouth Stomach ‘Gonad’ Horseshoe-shaped lophophoral tentacles Epistome _—Anus Nephridium Metacoel | — Secreted tube P. Brachiopoda a.k.a. lamp shells Marine, mostly extinct P. Nemertea a.k.a. proboscis or ribbon worms Structurally acoelomate, with a small fluid-filled sac that may be a vestigial coelom Closed circulatory system, but no heart P. Mollusca a.k.a. mollusks 8 classes, including: C. Polyplacophora (chitons) Shell divided into 8 plates P. Mollusca a.k.a. mollusks 8 classes, including: C. Gastropoda (snails and slugs) Single shell or lacking shell P. Mollusca a.k.a. mollusks 8 classes, including: C. Gastropoda (snails and slugs) Single shell or lacking shell P. Mollusca a.k.a. mollusks 8 classes, including: C. Cephalopoda (squids, octopuses, nautiluses) Only mollusks with closed circ. system and complex brain P. Annelida a.k.a. segmented worms Open eae P. Annelida a.k.a. segmented worms Segmented Coelomate Closed circulatory system Coelom P. Annelida a.k.a. segmented worms 3 classes: C. Hirudinea Leeches P. Nematomorpha a.k.a. horsehair or gordian worms Not required to know P. Priapulida a.k.a. penis worms Not required to know P. Nematoda a.k.a. roundworms Fig. 4.19 Nematode body forms Nonsegmented P. Nematoda a.k.a. roundworms Nonsegmented No circulatory or respiratory systems Mouth Gut Anus P. Nematoda a.k.a. roundworms Nonsegmented No circulatory or respiratory systems Pseudocoelomate P. Arthropoda Open circulatory system Hemolymph (the open-circulation system equivalent of blood) carries dissolved gases through short vessels and the hemocoel (main body cavity in adults, since coelom is reduced) P. Arthropoda As in much of modern systematics, classes are in flux; nevertheless, here are 5 main groups: Trilobites – all extinct during Permain mass extinction ~250 mya P. Arthropoda Cheliceriforms – horseshoe crabs P. Arthropoda spider (tarantula) scorpion tick mite Cheliceriforms: Arachnids – spiders, ticks, scorpions, mites P. Arthropoda Adults generally have 4 pairs of walking legs Some produce silk Cheliceriforms: Arachnids – spiders, ticks, scorpions, mites P. Arthropoda Simple eyes (each with a single lens) Eyes of black widow spider Cheliceriforms: Arachnids – spiders, ticks, scorpions, mites P. Arthropoda Hexapods: insects P. Arthropoda Adult often has 2 pairs of wings Hexapods: insects P. Arthropoda Sometimes 1 pair of wings; sometimes none Hexapods: insects P. Arthropoda Metamorphosis – transition between distinct (often dramatically different) developmental stages Larva (maggot, caterpillar) Pupa (transition to adult) Adult (often winged) Hexapods: insects P. Arthropoda Adult generally has compound eyes Hexapods: insects Insects Some of the major orders (26 in total): Order Coleoptera – Beetles Order Hemiptera – True Bugs Order Homoptera – Aphids and their kin Order Hymenoptera – Ants, Bees, Wasps Order Isoptera – Termites Order Lepidoptera – Butterflies and Moths Order Odonata – Dragonflies and Damselflies Order Orthoptera – Crickets, Grasshoppers, Katydids Order Siphonaptera – Fleas See also Fig. 33.37 P. Arthropoda Often have 5 or more pairs of legs Crustaceans P. Arthropoda Generally have compound eyes Crustaceans Deuterostomia Deuterostome developmental pathway Ancestral colonial choanoflagellate Eumetazoa Bilateria Deuterostomia P o ri fe ra C n id a ri a O th e r b ila te ri a n s ( in c lu d in g N e m a to d a , A rt h ro p o d a , M o llu s c a , a n d A n n e lid a ) E c h in o d e rm a ta C h o rd a ta Coelomates Figure 33.2 P. Echinodermata However, their larvae are obviously bilaterally symmetrical Sea star larva Sea star adult P. Echinodermata Sea cucumber Brittle star Sea urchin Sand dollar P. Echinodermata Sea cucumber Brittle star Sand dollar Sea urchin Calcium carbonate endoskeleton