Transcript 10 Lecture - Protists,Sponges and Cnidarians

Today
1) Quiz
2) Kingdom Protista
3) Kingdom Animalia
- Phylum Porifera (sponges)
- Phylum Cnidaria (jellies)
Classification System
• Kingdom, Phylum, Class, Order, Family,
Genus, Species
• In the 5-Kingdom system of classification,
what are the 5 Kingdoms?
Review: Which
kingdoms include
only prokaryotes?
Which kingdoms
include only
eukaryotes?
Kingdom Protista
• All Eukaryotes
• 3 Categories
1) Photosynthetic – plant-like (algae)
2) Absorptive – fungus-like
3) Ingestive – animal-like (protozoa)
Fungus-like Protists: Slime Molds
• Classification: Domain Eukarya, Kingdom
Protista
• Prokaryote or Eukaryote: Eukaryote
Slime Mold
Plasmodium –
multinucleate
mass of
protoplasm lacking
cell walls, but
surrounded by a
thin, flexible
membrane
Slime Mold
• How do they obtain food?
heterotrophs, engulf food by phagocytosis,
moves nutrients around in the
body by
cytoplasmic streaming
• How do they move?
Flagellated or amoeboid cells
• Where can you find them?
Damp places
• How do they reproduce?
Sexually with spores
• What color are they?
gold
Protozoans: Animal-like Protists
• Informally classified
based on movement
1) Amoeba – move by
cytoplasmic extensions
called psuedopodia
2) Flagellates – move by
single long whip-like
flagella
3) Ciliates – move by means
of many cilia
Amoeba
Know the purpose of the food vacuole,
contractile vacuole, nucleus, and
pseudopodia.
Flagellates
One flagellate, Trypanosoma, causes
African Sleeping Sickness
1) Infected
Tsetse fly bites
human,
2) Trypanosoma
enters blood
stream, causes
lethargy, swollen
lymph nodes,
3) effects central
nervous system
and causes
death if not
treated.
Every day, about 100
people die from the
disease.
Ciliates
Know each term in the diagram
Kingdom Animalia
Everything we look at from now on is in
the animal kingdom.
What is an animal?
What is an animal?
•
•
•
•
•
Multicellular
Heterotrophic
Eukaryotic
Lack cell walls, but have cell membranes
Nervous tissues and muscle tissue are
unique to animals, but not all have them
• Most animals reproduce sexually
Animal Evolution: Symmetry
* Note that some sponges have radial symmetry.
Image from : http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_7.html
Animal Characteristics
General Animal Features
 The ancestral animals at the beginning of
the evolutionary tree are eukaryotic and
multicellular.
 They developed adaptations in structure
that enabled them to function in
numerous habitats.
Animal Characteristics
Feeding and Digestion
 Animals are heterotrophic.
 The structure or form of an animal’s
mouth parts determines how its mouth
functions.
Animal Characteristics
Support
 Invertebrates
 Exoskeletons
 Hard or tough outer coverings that
provide a framework of support
 Protect soft body tissues
 Provide protection from predators
Support
 Vertebrates
 Endoskeletons
 Protect internal organs
 Provide support for the body
 Provide an internal brace for muscles
to pull against
Animal Characteristics
Gut (where food travels when eaten)
 1-way gut
 Has 2 openings (mouth and anus) in
which food travels in 1direction.
 2-way gut
 Has 1 opening in which food goes in and
waste leaves through same opening
 Gutless
 No gut (like a sponge)
Introduction to Animals
Chapter
24
24.1 Animal Characteristics
Early Development
 The zygote undergoes mitosis and a
series of cell divisions to form new cells.
 The cells continue to divide, forming a fluidfilled ball of cells called the blastula.
 The blastula continues to undergo cell
division as some cells move inward to
form a gastrula.
Introduction to Animals
Chapter
24
24.1 Animal Characteristics
Animal Characteristics
Triploblastic embryonic development – protostome and
deuterostome coelomates
Introduction to Animals
Chapter
24
24.2 Animal Body Plans
Development in Coelomate Animals
 Protostomes
 The mouth develops from the first opening in
the gastrula.
 Deuterostomes
 The anus develops from the first opening in
the gastrula.
Introduction to Animals
Chapter
24
24.2 Animal Body Plans
Evolution of Animal Body Plans
 Anatomical features in animals’ body
plans mark the branching points on the
evolutionary tree.
 Relationships on this tree are inferred by
studying similarities in embryological
development and shared anatomical
features.
Animal Body Plans
Body cavity development in tripoloblastic animals
A Coelom is a body cavity
1) Acoelomate animals (like
flatworms and flukes) do not
have a coelom.
2)
Pseudocoelomate animals
(like roundworms) have a
body cavity lined on the
inside with endoderm and the
outside with mesoderm
3) Coelomate animals
(segmented worms,
arthropods, molluscs,
echinoderms, chordates)
have a body cavity lined fully
with mesoderm cells.
Image from : http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookDiversity_7.html
Animal Evolution: Body Plans
• Primitive animals have a sac-like body plan.
Higher animals have a “tube-within-a-tube”
body plan
- Sac-like body plan has only one opening.
Sac-like body plan animals do not have tissue
specialization or development of organs.
- “Tube-within-a-tube” plans have two openings,
allows specialization of parts along the tube.
Animal Evolution: Germ Layers
• Triploblasty: Three Tissue Layers
- Many, but not all, animals have three tissue
layers as they develop embryologically:
endoderm, mesoderm, and ectoderm.
• - Porifera – have no tissue layers
- Cnidarians – have only 2 tissue layers
- All of the more advanced phyla have 3 tissue
layers (are triploblastic)
Porifera: Sponges
• Representatives
Sponges, about 9000
species
• Habitat
Marine and
freshwater, usually in
shallow water,
sensitive to pollution
Porifera
• Symmetry
asymmetrical
• Body Cavity/germ
layers
one central cavity
called the
spongocoel,
no tissues/germ
layers
spongocoel
Porifera
• Skeleton
none, spongin and
structures called
spicules provide
support
Porifera
• Movement – sessile
• Digestion - filter
feeders, water brought
in through ostia (pores)
and circulated in the
spongocoel where
choanocytes digest the
food by phagocytosis
(intracellular digestion)
• Gas Exchange –
diffusion, choanocytes
(flagellated) cells keep
a current of oxygenated
water moving through
the spongocoel
Porifera
• Excretory System
none
• Nervous System
none
• Circulatory System
none
• Reproductive System
Asexually by budding
or fragmentation
Sexually by
producing sperm and
eggs. Many sponges
are hermaphrodites
5 quick facts about Sponges
1. Tops on the menu 4. For more nutrition,
of a Hawk’s bill
a sponge will
turtle
allow
phytoplankton and
2. Shrimp will feed
microbes to take
on internal cells
up
residence
3. Crabs will tear off
5. Everything can
a bit to carry on
regenerate &
their backs
repopulate
Porifera: Terminology
• Spongocoel – body cavity
• Osculum – opening to the spongocoel
• Ostia – pores on the outside of the body through
which water (containing food and oxygen) enters
• Spicules – cells with silica or CaCO3 that gives
the sponge some support
• Choanocytes – flagellated cells that keep water
currents moving through the spongocoel;
capture 80% of food
• Oocytes & Spermatocytes – reproductive cells
Porifera: Terminology
• Amoebocytes or Archaeocytes
(Amoeboid cell on diagram) – capable of
transforming into any other type of cell;
roles in feeding and clearing ostia
• Sclerocytes – cells that secrete spicules
• Pinacocytes – plate like cells that cover
the external side of sponge. Can digest
food particles too large to enter ostia
Porifera: Terminology
• Porocytes – ostia tube-like cells that form
closable inlet valves
• Monoecious – having both male and
female sexual organs
• Dioecious – having either male or female
sexual organs
• Spongin - a scleroprotein that produces
flexible fibers which form “skeletons” of
sponges
Anatomy of some sponges
• Color code the diagram so you can see
the various cells and structures.
• Read and follow the instructions and the
information
Figure 9.7
Ascon(oid)
Sycon(oid)
Leucon(oid)
Asconoid body structure
• Asconoid –
simplest body
structure. Tube or
vase shape.
Seldom exceed 1
mm (.5 inch) in
diameter
Pinacocytes
Mesohyl
Choanocytes
Water flow
Syconoid body structure
• Syconoid – variation
on asconoid with
pleats or folds in
body wall. Increase
in number of
choanocytes. Can
grow to a few cm in
diameter
Pinacocytes
Mesohyl
Choanocytes
Water flow
Leuconoid body structure
• Leuconoid – can
grow to over 1 m
(3.3 ft) in diameter.
Fills interior almost
completely with
mesohyl and
greatly increases
number of
choanocytes
Pinacocytes
Mesohyl
Choanocytes
Water flow
Short story
• Write a short story using vocab
terms for sponges. You can be
serious, dramatic, funny,
ridiculous, suspenseful, exciting,
or a thriller. Be creative.
Cnidarians
Cnidaria
• Representatives - Over 10,000 species
Class Hydrozoa – hydra, Obelia, polyp is dominant
Class Schyphozoa – jellyfish, medusa is dominant
Class Anthozoa– sea anemones and corals, only polyp
• Habitat
Mostly marine
Cnidaria
Symmetry
radial
Body Cavity/germ layers
one opening called the
gastrocoel,diploblastic
(i.e. only 2 germ layers),
has a mesoglea but that
isn’t a true germ layer
Polyp
Medusa
Skeleton
none –
supported
by water
Cnidaria
• Movement – Polyp is sessile or
free-floating. Medusa is freefloating or can move by weak
contractions
• Digestion – tentacles grab and
push prey into the gastrocoel
where it is digested
extracellulary. Note that even
though the gastrocoel
functions like stomach, it can’t
be called that because it has
only one opening.
• Gas Exchange – Diffusion, no
specialized organs
Cnidaria
• Excretory System
none
Asexual
Sexual
• Circulatory System
none
• Nervous System
none
• Reproductive
System
Some asexual
reproduction by
budding, some
sexual reproduction
with separate
sexes
Cnidaria: Terminology
• Gastrovascular cavity – central body cavity
• Oral vs. aboral surface – mouth side vs. non-mouth
side
• Polyp vs. Medusa – polyp is sessile with mouth up,
medusa is floating, flattened, with mouth-down
• Basal disc – bottom end of the gastrovascular cavity
• Mouth – opening to the gastrovascular cavity
• Tentacles – structures that capture prey and shove
them into the mouth
• Cnidocytes – capsule cell containing a fine coiled
thread, which, when discharged, functions in
defense and prey capture
• Nematocysts – stinging components of cnidocytes
Compare and
contrast
sponges and
jellies.
Compare and
contrast
Kingdom
Protista and
Kingdom
Animalia.
NEXT WEEK
• Quiz
-- 7 Q over Protozoa, Porifera, Cnidaria
-- 3 Q over Lab Topic 3 (worms)