General Body Plan - PowerPoint PPT Presentation

About This Presentation
Title:

General Body Plan

Description:

General Body Plan Diploblastic epidermis gastrodermis Tissue Radially symmetrical Cnidocytes – PowerPoint PPT presentation

Number of Views:117
Avg rating:3.0/5.0
Slides: 87
Provided by: kmc112
Learn more at: https://www.bio.fsu.edu
Category:

less

Transcript and Presenter's Notes

Title: General Body Plan


1
General Body Plan
  • Diploblastic
  • epidermis
  • gastrodermis
  • Tissue
  • Radially symmetrical
  • Cnidocytes

2
General Body Plan
Dimorphism 2 different body forms are usually
present in the life cycle
aboral
oral
aboral
oral
3
3 Classes
  • Hydrozoa polyp dominant
  • Scyphozoa medussa dominant
  • Anthozoa no medussa

4
The Acoelomates
  • Trploblastic animals without a coelom

5
Acoelomate Characteristics Triploblastic
3 Tissue Layers gastrodermis mesoderm/
mesenchyme epidermis
3 Embryonic Germ Layers endoderm mesoderm e
ctoderm
6
zygote
blastocoel
archenteron
blastopore
ectoderm
endooderm
mesoderm
7
Acoelomate Characteristics Triploblastic
Gut
Mesoderm
Ectoderm
Endoderm
8
Acoelomate Characteristics No coelom
What is a coelom? A body cavity that is
completely surrounded by mesodermal tissue. A
coelom is not open to the outside of the animal.
9
What is a coelom?
10
Acoelomate Characteristics No coelom
gut
gut
endoderm
endoderm
gut
11
Acoleomate CharacteristicsLevel of Organization
Organ
  • Tissues are organized into organs
  • mesodermal tissue gives rise to many organs

12
Acoleomate CharacteristicsBody Plan
Bilateral Symmetry
Anterior toward the front of the body
Posterior toward the rear of the body
13
Acoleomate CharacteristicsBody Plan
left
anterior
dorsal
right
posterior
ventral
14
Body Plan
Cephalization the concentration of sensory
organs in the head of the animal
Eye spots photosensitive organs
Auricles chemoseneory organs
15
Acoelomate Phyla
1. Gnathostomulida 2. Platyhelminthes 3.
Nemaertea
16
Phylum Platyhelminthes
  • the flatworms

17
  • Phylum Platyhelminthes
  • Mostly aquatic, although there are a few
    terrestrial species.
  • Most are small (a few mm), but some can grow to
    be sever meters long.
  • Many are endoparasites of vertebrates.

18
Feeding and Digestion
  • Feeding
  • Free-living, carnivorous

Many predatory forms have a pharynx that is used
to capture prey
19
Feeding and Digestion
Pharynx the pharynx is an extension of the gut
that can be extruded though the mouth.
20
Feeding and Digestion
  • Feeding
  • parasitic

Parasitic forms often have modified feeding
structures (e.g. the anterior end of a tapeworm)
hooks
suckers
21
Feeding and Digestion
  • Digestion
  • incomplete digestive system

mouth
gut saclike
pharynx
pharyngeal opening
22
Feeding and Digestion
  • Digestion
  • many forms have a branched gut

The trilobed gut of a planarian.
23
Feeding and Digestion
  • Digestion
  • the digestive system is reduced (or absent) in
    many parasitic forms

24
Feeding and Digestion
intestine
Taenia pisiformis intestinal parasite NO
DIGESTIVE SYSTEM !
Bdelloura candida Free-livingbranched gut
Grylodactylus liver fluke relatively unbranched
gut
25
Feeding and Digestion
  • Digestion
  • extracellular (in the intestine)
  • proteolytic enzymes released by gastroodermal
    tissues
  • intracellular
  • phagocytosis by gastrodermal cells

26
Osmoregulation and Excretion
  • Osmoregulation the maintenance of salt/water
    balance
  • Protonephridia and flame cells

27
Osmoregulation and Excretion
Protonephridia
Protonephridia a system of tubules used to
collect fluid and transport it to the outside of
the body
28
Osmoregulation and Excretion
The beating of the flame cell cilia creates
negative pressure which pulls fluid out of the
body
protonephridia
flame cell
29
Osmoregulation and Excretion
  • Excretion
  • Diffusion of waste

30
Nervous System
The Cnidarian nerve net
receptor
neuron
31
Nervous System
Platyhelminthes have a more complex nervous system
Cerebral ganglia
Lateral nerve cords
Transverse nerves
32
Nervous System
pigment cup
retinular cells
light sensitive region
33
Support and Locomotion
  • Skeletal System
  • No skeletal system

34
Locomotion
Many small flatworms crawl on slime trails
using cilia.
35
Locomotion
cilia on the dorsal epidermis
rhabdites produce mucus
36
Locomotion
Large species use circular and longitudinal
muscles to swim.
37
Locomotion
circular muscles
longitudinal muscles
38
Reproduction
Asexual fission many flatworms are capable of
reproducing asexually by constricting their
bodies and separating into two individuals
39
Reproduction
Asexual Periods of asexual reproduction are
common in many parasites.
40
Reproduction
  • Sexual
  • usually monoecious, but most must cross fertilize
  • Internal fertilization (usually reciprocal sperm
    transfer)

41
Phylum Platyhelminthes
  • Class Turbellaria
  • Class Trematoda
  • Class Cestoda

parasitic
42
Class Turbellaria
Free-living flatworms
43
Body Plan
cerebral ganglion
eye spot
anterior branch of intestine
ovaries
nerve cords
pharynx
testes
posterior branches of intestine
44
Digestive System
pharynx
45
Digestive System
polyclad
triclad
46
Reproduction
Asexual fission many flatworms are capable of
reproducing asexually by constricting their
bodies and separating into two individuals
47
Reproduction
  • Sexual
  • Internal fertilization
  • Simple life cycle

48
Phylum Platyhelminthes
  • Class Turbellaria
  • Class Trematoda
  • Class Cestoda

parasitic
49
Adaptations for Parasitism
Increased reproductive potential The presence of
adhesion organs Poorly developed sensory
systems Reduced or absent digestive
system Resistant cuticle Complex life cycles
50
Class Trematoda
Parasitic Flukes Endoparasites of many animals
51
Body Plan
oral sucker and mouth
intestine
ventral sucker
reproductive organs
52
Complex Life Cycle
Most Trematodes have at least two hosts in their
life cycle e.g. the Chinese liver fluke
  • Clonorchis
  • Found throughout Asia
  • Infects 30 million people
  • 1 fluke can produce 4000 eggs/day and live for gt
    8 years

53
Complex life cycles another example
  • Schistostoma
  • Found throughout Africa and South America
  • Infects 200 million people

54
oral suckers
female
gynecophoric canal
male
55
The creation of the Aswan Dam led to an epidemic
of schistosomiasis. About 50 of Egyptians
living near the dam are now infected.
56
Class Cestoda
57
Body Plan
2 body regions scolex and proglottids
scolex
proglottids
58
Body Plan tegument
glycocalyx
Microtriches increase SAV And nutrient
absorption
Syncitial epidermis no cell membranes
circular muscles
longitudinal muscles
nucleus
59
Body Plan
Scolex
suckers
rostellum
60
Body Plan
Proglottids repeating segments containing
reproductive organs May be immature, mature, or
gravid
61
Class Cestoda
Immature proglottids
Immature proglottids are found at the anterior
end of the tapeworm and contain no noticeable sex
organs
62
Class Cestoda
Mature proglottids
Mature proglottids are found in the middle of the
tapeworm and contain noticeable sex organs
63
Class Cestoda
Female organs
yolk gland
ovary
seminal receptacle
genital pore
vagina
uterus
64
Class Cestoda
Male organs
genital pore
seminal vesicle
sperm duct
testes
65
Class Cestoda
  • Individuals are monoecious, Reproduction is
    sexual
  • between proglottids on 1 individual
  • between individuals
  • Sperm do not usually fertilize eggs produced
    within the same proglottid

66
Class Cestoda
Gravid proglottids
Gravid proglottids are found at the posterior end
of the tapeworm and are shed in the feces. A
single proglottid can contain thousands of eggs.
67
Cestoda Life Cycle
Adult tapeworm (in host intestine)
Gravid proglottids
Vertebrate host 2
Infective stage in host muscle
eggs
Vertebrate host 1
68
(No Transcript)
69
How are these guys different from
70
these guys?
71
How are parasites and disease different from
predators?
  • Predators kill their prey, but hosts are usually
    not killed by parasites. Parasites affect hosts
    in more subtle ways.
  • Some examples of non lethal effects of trematode
    parasites on their hosts.

72
Trematodes and Host Behavior
Fundulus parvipinnis
Euhaplorchis califoniensis
Lafferty and Morris 1996
73
Trematodes and Host Morphology
Limb deformities in amphibians have been recorded
since the 1950s. Since the early 1990s, there
has been an apparent increase in the number of
frogs found with limb deformities. Several
hypotheses have been proposed to explain these
Pesticides, UV, parasites
74
Cysts formed by the trematode, Ribeiroia
75
Deformities
Survival
Deformities
Survival
Johnson, et al. 1999
76
Are deformed frogs more likely to be eaten by
snakes?
Ribeiroia life cycle
77
  • There might be more to the story than just
    parasites
  • Deformities are more common near agricultural
    run-off.

Agricultural run-off
No run-off
From Kiesecker 2002
78
  • There might be more to the story than just
    parasites
  • Pesticides affect a frogs immune response to the
    parasite.

From Kiesecker 2002
79
  • There might be more to the story than just
    parasites
  • Trematodes do not induce this type of deformity.

80
References Kiesecker, J. M. 2002. Synegism
between trematode infection and pesticide
exposure a link to amphibian limb deformities in
nature. PNAS 99(15) 9900-9904. Johnson, P.T.J.,
et al. 1999. The effect of trematode infection
on amphibian limb development and survivorship.
Science 284 802- 804.
81
Phylum Nemertea
  • the ribbonworms

82
Physiology
  • Feeding
  • Free-living, carnivorous
  • Have an eversible proboscis that is not connected
    to the digestive system

83
Physiology
rhynchocoel
proboscis
mouth
anus
rhynchocoel
84
Physiology
  • Digestion
  • extracellular (in the intestine)
  • intracellular (by gastrodermal cells)
  • intestine is unbranched
  • complete system (mouth and anus)

85
Physiology
  • Reproduction
  • Asexual
  • Some species are capable of reproducing asexually
    through fragmentation and regeneration

86
Physiology
  • Reproduction
  • Sexual
  • usually dioecious
  • Internal fertilization
Write a Comment
User Comments (0)
About PowerShow.com