Transcript AP Animals

Animal Development and
Phylogeny
 Animals:
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Multicellular
Consumers
Eukaryotic
Motile at some point in their development
Reproduce sexually (some have asexual
options)
 Have a variety of evolutionary advancements
The Animal Family Tree
 The most primitive animals are conglomerations
of cells with little specialization and no true
tissues (sponges)
 More advanced animals have cells organized into
distinct tissues (Eumetazoa)
 Diploblastic organisms have only 2 tissue
layers (cnidarians and ctenophorans)
 Triploblastic organisms have 3 tissue layers
(look in a mirror)
Figure 32-5
Asymmetry
Sponge
No plane of
symmetry
Radial symmetry
Jellyfish
Multiple
planes of
symmetry
Bilateral symmetry
Lizard
Single plane
of symmetry
Posterior
Anterior
Animal Activitiesminor grade and NOTES
 Use the animal activities to determine
evolutionary patterns in Kingdom Animalia.
 Complete each one on your own paper. Use a
textbook, online notes, online resources and
previous knowledge.
 The last question for each sections is a
Thinkable this is the question that makes the
connection between information and
knowledge 
A word about Germ layers
 “Germ” layers refers to the 3 layers of tissues
in most animals. The layers are present at
gastrulation during embryonic development
 Ectoderm is the outermost layer of cells. It
gives rise to the nervous system, skin, hair
and nails
 Mesoderm is the middle layer of cells and is
the most versatile. It becomes the skeleton,
muscles, inner layer of skin, visceral lining,
fatty tissues, and circulatory system
 Endoderm is the innermost layer of cells. It
gives rise to the gut and organs associated
with digestion and excretion
Introduction to Kingdom Animalia
 Evolution
 Work through the first two activities:
Symmetry and Tissue Layers
 30 minutes.
Why Symmetry?
 Most primitive organisms are
asymmetric, slightly more advanced
are radially symmetric, and the most
advanced are bilaterally symmetric
 Why?
 Segmentation is tied to bilaterally
symmetry.
 Organisms with bilateral symmetry tend
to have more advanced features such as
sensory organs. Cephalization!!!!
The Animal Family Tree
 Animals with true tissues and bilateral symmetry
are considered the most advanced and classified
into three groups:
 Specialized tissues and basic organs but no body cavity
(acoelomates)
 Still more advanced organisms develop a body cavity
which is unlined (pseudocoelomates)
 The most advanced organisms develop a body cavity lined
in mesoderm (coelomates)
 Body cavities allow organisms to form sections for
specialized organs and organ systems.
 This leads to segmentation=Evolutionary Money!
Figure 32-6
Acoelomates have no enclosed body cavity.
No coelom
Skin
(from ectoderm)
Muscles, organs
(from mesoderm)
Gut
(from endoderm)
Pseudocoelomates have an enclosed body cavity partially
lined with mesoderm.
Pseudocoelom
Skin
(from ectoderm)
Muscles, organs
(from mesoderm)
Gut
(from endoderm)
Coelomates have an enclosed body cavity completely lined
with mesoderm.
Coelom
Skin
(from ectoderm)
Muscles, organs
(from mesoderm)
Gut
(from endoderm)
Family Tree Continued
 The coelomates are further divided into two
groups:
 Protostomes-”proto”=first, “stome”=mouth,
 Deuterostomes-”deutero”=second,
“stome”=mouth
 Groups are based on the fate of the Blastopore
during gastrulation
 Protostomes are all invertebrates.
 Deuterostomes are echinoderms and
chordates.
Figure 22-12
Figure 32-8
PROTOSTOMES
Cleavage
(zygote undergoes
rapid divisions,
eventually forming
a mass of cells)
DEUTEROSTOMES
2-cell
stage
4-cell
stage
8-cell
stage
Gastrulation
(mass of cells
formed by cleavage
is rearranged to
form gut and
embryonic tissue
layers)
Longitudinal
section
Spiral
cleavage
Radial
cleavage
Mouth
Pore
becomes
mouth
Anus
Coelom formation
(body cavity lined
with mesoderm
develops)
Pore
becomes
anus
Gut
Gut
Coelom
Mesoderm
Block of solid
mesoderm splits
to form coelom
Cross section
Mesoderm
Mesoderm pockets
pinch off of gut
to form coelom
Figure 32-10
Animalia
Bilateria
Deuterostoma
Protostoma
Ecdysozoa
Lophotrochozoa
Segmentation
Acoelom
Pseudocoelom
Pseudocoelom
Radial
symmetry
Segmen(in adults)
tation
Growth by molting
Protostome development
Phylogenetic tree based on similarities and
differences in the DNA sequences of
several genes from various animal phyla.
The bars along the branches indicate when
certain morphological traits originated
Deuterostome
development
Coelom
Triploblasty (origin of mesoderm)
Bilateral symmetry and cephalization
Radial symmetry
Diploblasty (ectoderm and endoderm)
Epithelial tissue
Multicellularity
Segmentation
Figure 32-1-Table 32-1a
Figure 32-1-Table 32-1b
Kindgom Animalia Activity
Continued……
 Write three columns on your paper:
Know
Think I Know
Don’t Know
 Sort the following terms into an
appropriate column for YOU:
Bilateria, Radiata, Acoelomates, Coelomates,
Pseudocoleomates, Protostome, Eumtazoa,
Parazoa, Choanoflagellate, Deuterostome
Animal Activity Continued…..
 Define the terms in your “Don’t
Know” Column using your notes,
neighbor, electronic devices or
textbook.
 Start with #3 on the activity sheet.
Use the pieces to help you sort and
resort but write the final product in
your notes.
 15 minutes
Animal Classification/Review
Molecular data continues to change our views on how
animals are grouped into phyla. The bilaterally
symmetric animals are particularly messy to classify
 There are some points of agreement with
respect to classification:
 All animals share a common ancestor
 Sponges are the base of the animals family tree
 Eumetazoa is a clade of animals with true
tissues (cnidaria and ctenophora, formerly
coelenterata)
 Most animal phyla belong to the Bilateria clade
and are organized based on the presence of a
coelom.
 Chordates and some other phyla belong to the
clade Deuterostoma
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Major Invertebrate Phyla
 Sponges were formerly called “Porifera” and are
organisms that have the following characteristics:
 Suspension feeding (capturing food from the
water as it travels through the body
 Pores on the outer surface pull in water and
send it out through the spongocoel and it’s main
opening, the osculum
 All are hermaphroditic
 Have a few specialized cells but no tissues:
 Choanocytes-collar cells that are flagellated for feeding
 Amoebocytes-mobile cells that have pseudopods and
carry nutrients around the body
 These are now split into 2 phyla:
 Calcarea
 Silicea
Figure 32-26
Pseudoceratina crassa
Eumetazoans
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This is a clade, consisting of 2 major phyla of diploblastic
organisms:
 Cnidaria (Includes: jellyfish, hydra, sea anemones,
etc)
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Radially symmetrical
Tissue layers (2 distinct-epidermis, gastrodermis)-mesoglea in
between (jelly)
2 forms-medusa (mouth down, free-swimming), and polyp
(mouth up, sessile)
Stinging nematocysts for defense and predation (inside the
cnidocytes)
1st organisms with a nervous system (primitive-nerve net,
no central control)
Food enters the mouth and broken down. Nutrients from the
food are absorbed by the surrounding cells and wastes are expelled
from the mouth (2-way digestive tract)
Ctenophora (Comb Jellies)
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Look like jellyfish, but move with cilia on their bodies
No cnidocytes/nematocysts, instead use colloblast secretions to
catch and hold onto prey
Actually have a nervous control structure called the Apical
Organ at one end of the body (sounds like a brain to me)
Figure 32-27
Polyps attach to substrates.
Aurelia aurita
Medusae float near the water surface.
Aurelia aurita
Figure 32-18
Motile larval anemone
Sessile adult anemone
Figure 32-3
Cnidarians and ctenophores are
diploblastic.
Cnidaria include hydra, jellyfish, corals,
and sea pens (shown).
Ctenophora are the comb jellies.
Ectoderm
Endoderm
This dark
blue comb
jelly…
…has just
swallowed
this white
comb jelly
Figure 32-4
Mouth
Tentacles
Tubular body
Basal disk
Captured prey will be
transferred to mouth
Figure 32-28
Pleurobrachia pileus
Rows of cilia
Sticky tentacles
Acoelomates
 Also called the flatworms b/c they have no
body cavity and a flattened body
 First organisms with bilateral symmetry and
cephalization
 Organisms with a two-way digestive tract
or none at all
 No need for lungs or gills because of the
flat body plan (O2 exchange via diffusion)
 Water-living or parasitic
Figure 33-13
Turbellarians are free living.
Pseudoceros ferrugineus
Cestodes are endoparasitic.
Taenia species
Trematodes are endoparasitic.
Dicrocoelium dendriticum
Rotifers
 Small, freshwater organisms with a ciliated
crown
 Have an alimentary canal with 1-way
digestion
 Some species can reproduce via
parthenogenesis and are all female, while
others have males only for the purpose of
reproduction
Figure 33-12
Rotaria rotatoria
Corona
Mollusca
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Bilaterally symmetric
Muscular Foot (ventral)
Rasping organ called the Radula
Coelomates
Open circulatory system
Primitive kidneys
Gills or primitive lungs
Several ganglia with a more complex nervous system
Examples include snails, slugs, chitons, limpets,
bivalves (clams, oysters, mussels, scallops),
chambered nautilis, squid, octopus
Figure 33-7b
Mollusc body plan (internal view)
Gill
Mantle
(secretes shell)
Visceral mass
(internal organs
and external gill)
Muscular “foot”
Figure 33-15
Scallops live on the surface of the substrate and
suspension feed.
Lima scabra
Most clams burrow into soft subtrates and suspension feed.
Water out
Siphons
Foot
Food
particles
Water in
Gill
Gills are thin structures for
gas exchange. They also trap
food particles as water passes
through them. Cilia move the
particles to the mouth
Figure 33-16
Snails have a single shell, which they use for protection.
Maxacteon flammea
Land slugs and sea slugs (nudibranchs) lack shells.
Chromodoris geminus
Bright colors warn
potential predators
of presence of
toxins
Figure 33-17
Tonicella lineata
Figure 33-18
Octopus dofleini
Nematodes
 Have round bodies (pseudocoel)
 Both free-living and parasitic
 Ex: hook worm, Ascaris, pinworm, trichina
worm, dog heartworm
 Often have complex life styles
w/intermediate hosts
 Often have male and female forms with
dimorphism
Figure 33-21
Strongyloides species
Nematodes
Annelids
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1st organisms with segmentation (metamerism)
Closed circulatory system but gas exchange occurs via
osmosis
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Double nerve cord, ganglia, lateral nerves in each segment
(metamere)
Taste, tactile, light sensation
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Bilaterally symmetric
Head (prostomium) and an anus-bearing terminal portion
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Hydrostatic skeleton in each segment
Figure 33-14
Most polychaetes are marine.
Alvinella pompejana
Chaetae
Most oligochaetes are
terrestrial.
Paranais litoralis
Most leeched live in freshwater.
Hirudo medicinalis
Arthropods
 Arthro=jointed, pod=foot, all have jointed
appendages
 Exoskeleton made of chitin (a protein) and
sometimes calcium carbonate
 Metamorphosis
 Bilateral symmetry, open circulation,
nervous system like that of annelids
 Have gills, air tubes, or book gills
 Defined body segments and developed
sensory organs.
Figure 33-7a
Arthropod body plan (external view)
Tagma
Head
Thorax
Abdomen
Jointed limbs
Exoskeleton
(covers body)
Segmented body
Figure 33-23
Spider, showing general chelicerate features
Dolomedes fimbriatus
Posterior region
Anterior region
Chelicerae
Mites are ectoparasitic.
Dermatophagoides species
Figure 33-24
Deep-sea lobster
Enoplometopus occidentalis
Red barnacle
Barnacles
secrete their
own shells
Carapace
Fiddler crab
Tetraclita species
Uca vocans
Compound
eyes on
stalks
Figure 33-23-Table 33-1-1
Figure 33-23-Table 33-1-2
Echinoderms
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Non-metameric adult with radial symmetry
Larvae are bilaterally symmetric
No head or brain, circular ring and radial nerves
Skeleton of embedded ossicles (calcium carbonate)
within the dermis
Pedicellariae for catching and moving food
Water vascular system with tube feet for locomotion
One-way digestive tract (sometimes with eversible
stomach)
Dermal branchae also help with vascularization
Usually separate sexes
Ex: sea stars, sea lillies, sea urchins
Figure 34-2
Figure 34-3
Figure 34-21
Invertebrate Chordates
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2 major Phyla: Cephalochordata and Urochordata
Widespread
Marine
Have a notochord at some point in their development
Pharyngeal Gill slits
Dorsal Nerve cord (tubular)
Postanal tail
Bilateral Symmetry
Segmented muscles in an unsegmented trunk
Ventral heart w/ closed circulation
Complete digestive system
Figure 34-5a
Figure 34-5b
Figure 34-23
Figure 34-24
Vertebrate Chordates
 Have all of the characteristics of invertebrate
chordates, but also have a vertebral column and
spinal cord
 These are also called the craniates-have a head
 Major Classes include:
 Myxini-Hagfish
 Pterromyzontida-Lampreys
 Chondrichtheyes-Sharks, skates, and rays
 Osteictheyes -Bony fish
 Amphibians-frogs, salamanders
 Reptiles-lizards, snakes, crocodillians
 Aves-Birds
 Mammalia-duh!
Figure 34-25
Figure 34-26
Figure 34-27
Figure 34-28
Figure 34-29
Figure 34-35
Figure 34-37
Figure 34-36
Figure 34-38
Figure 34-31
Figure 34-32
Figure 34-33
Animal Samples (10 minutes each)
 View each sample.
 Describe the organism in regards to the
following terms:
 Symmetry Type?
 Deuterostome or Protostome?
 Cephalization?
 Name the organism if you know what it is.
 Group the organism into one of the Animal
Phyla.
Trends in Chordate Evolution
 From plain chordate characteristics to
having a cranium
 From cranium to jaw (made from gills of
fish)
 Tetrapodal body plan (made from fins of
fish)
 Amniotic (membranous) egg-waterproofing
 Feathers (from scales of reptiles)
 From oviparity (monotremes) to viviparity
(marsupials and eutherians)
Figure 34-10
Figure 34-12
Figure 34-14
Figure 34-16
Figure 34-17