Topics 5-8 Flashcards
what phylum is defined by:
-one single species
-two germ layers
-may have tissue
phylum placozoa
what phylum is defined by:
- Multicellular
– Incipient tissues
– Aggregation of cells
differentiated for various
functions
– Sessile although embryo are
free-swimming
– Filter feeder, draws water
through tiny pores
-no true tissue
phylum porifera
what does sessile mean?
not moving
what is the basis of sponge classification?
composition (calcium vs silica) and shape
outer layer of cells of sponges are called? they are also not tissue, but have specialized cells.
pinacoderm
flagellated collar cells that keep the current flowing via beating of flagella
choanocytes
what functions do pinacocytes and archeocytes preform?
facilitate feeding
small particles are taken into choanocytes by ______ and protein molecules may be taken in by _____ in sponges
phagocytosis; pinocytosis
what are the three types of sponge bodies from most simple to most complex?
asconoids, synconiods, and leuconoids
this body part pulls water through the pores and extracts food particles in sponges?
choanocytes
what is an osculum?
an opening in a sponge that releases water
this sponge body types is folded outwards with radial canals, water enters through tiny openings called prosopyles, and contains internal pores called apopyles; spongocoel instead of choanocytes
syconoids
this sponge body uses choanoctyes and has clusters of flagellated chambers which are filled from incurrent canals and discharge to excurrent canals
leuconoids
the connective “tissue” of sponges found in fibrils, skeletal elements, and amoeboid cells
mesohyl or mesenchyme
amoeboid cells that move about in the mesohyl with many functions
archaeocytes
sclerocytes secrete
spiculess
spongocytes secrete
spongin
collencytes secrete
fabrilliar collagen
lophocytes secrete
large amounts of collagen
thin, flat, epithelial-like cells that cover the exterior and interior surfaces of sponges almost like real tissues
pinacocytes
Complete reorganization of the
structure and function of
participating cells or bits of
tissue occurs in
somatic embryogenesis
what are two means of asexual reproduction in sponges?
fragmentation and bud formation
what is a gemmule?
an external bud formation that can survive harsh environmental conditions; live cells within them escape through micropyles and develop into new sponges
monoecious means
both male and female sex cells in one body
zygote is retained within parent and provided with nourishment until it is released as ciliated larva; most sponges are this
viviparous
sponges release both sperm and oocytes into water for external fertilization
oviparous
The free-swimming larva of most sponges is a solid-bodied ____
parenchymula
The outwardly directed flagellated cells of the parenchymula become
choanocytes
in sponge sexual reproduction, ____- become choanozytes, archaeocytes, and collencytes while ____ give rise to pinacoderm and sclerocytes
micromeres; macromeres
which class of porifera is defined by:
Calcareous sponges with spicules
of calcium carbonate
– Spicules are straight (monaxons)
or have three or four rays
– Most are small with tubular or
vase shapes
– Many are drab in color, but some
are bright yellow, green, red, or
lavender
– Leucosolenia (Scypha) and Sycon
(Grantia) are marine shallow-
water
– Asconoid, syconoid and leuconoid body forms
class calcarea
which class of porifera is defined by:
Glass sponges with six-rayed spicules of
silica bound together to form network
– Deep-sea; vase or funnel shaped bodies
attached by stalks of root spicules onto the
substrate (radial symmetry in some)
– Have syncytial cell structure
class hexactinellida
bilayered, sheet-like
and tubular with collagenous mesohyl cells
Trabecular reticulum
unusual cells that make
flagellated outgrowths called collar bodies
whose flagella beat to move
choanoblasts
which class of porifera is defined by:
Contains 95% of living sponge species include most large sponges
– Spicules are siliceous but not six rayed and may be absent or bound together by spongin
– Leuconoid body form for all species
– All marine except for Spongillidae, the freshwater sponges
– Marine demosponges are highly varied in color and shape, with some growing to several meters in diameter.
class demospongiae
which class of porifera is defined by:
-Mostly marine with a variety of colors but live in cryptic habitats
– Generally found near shore but
have deep water forms
– true
basement membrane
(extracellular matrix; ECM) under pinacoderm
– Also have adherens cell
junctions that form true tissues unlike other sponges
– Divided into two clades based
on absence or presence of
spicules
class homoschleromorpha
what trait of sponges is homologous to other animals?
proteins for cell adhesion and cell-signaling
what traits do sponges have in common with other animals?
Proteins for cell adhesion and cell-signaling are homologous to other animals
– Some sponges have basement membrane with collagen and adherens
junctions with cadherin molecules that connect epithelial cells
– Sponge have blastula and some form gastrula stages like many animals
what is the single species of phylum placozoa?
Trichoplax adhaerens
what are some traits of the Trichoplax adhaerens?
- Tiny (2-3 mm) marine form that is plate-like and
has no symmetry - No major organs, no muscular or nervous system
- Lacks basal lamina and ECM but has genes for it
- Body has dorsal epithelium to cover cells and
have thick ventral epithelium of monociliated
cells and nonciliated gland cells - Contain multinucleated fibrous “cells” within a
contractile syncytium - Placozoans glides over food, secretes digestive
enzymes, and absorb nutrients - Divide asexually and produce “swarmer” stages
by budding. - No sexual stages have been seen but have
isolated eggs in the laboratory - Considered diploblastic
cnidocytes that
contain a specialized stinging organelle
nematocyst
are cnidarians typically sessile (free-floating)
yes
cnidaria adapted to a sedentary or sessile lifestyle
polyp or hydroid form
cnidaria adapted to free-living and floating existence
medusa or jellyfish form
in polyp form, the mouth leads into a blind ____
gastrovascular cavity
in polyp form, the aboral end is attached to substrate by ____
pedal disc
how does polyp form reproduce?
asexually via budding, fission, or pedal laceration
what are the two types of polyps?
colonial forms and in class hydrozoa (or hydranths)
these reproductive polyps do not have tentacles and typically become medusae
gonangia
in medusas, they have sensory organs (3). what are they?
statocysts (orientation in water)
ocelli (light sensors)
nerve ring (sensory information to motor response)
cnidarians start with zygotes developing into _____, which settles on hard substrate and metamorphoses into a polyp
planula
how do medusas and polyps reproduce differently?
medusas - sexually
polyps - asexually
how is a cnidarian’s body structured? (in terms of body wall)
inner gastrodermis
middle mesoglea
outer epidermis
in Hydra sp., the _____ contains epitheliomuscular, interstitial, gland, sensory, cnidocytes, and nerve cells
epidermis
what makes cnidarians effective predators? what does the body part do?
cnidocytes produce over 20 types of cnidae that can be discharged, reabsorbed, and replaced
what is the primary example of a cnidae?
nematocysts, which can inject toxin for prey capture or defense
what is an operculum?
covers the end of a nematocyst (cnidae)
how do polyps tend to feed and digest?
since they are carnivorous, they catch prey with tentacles and pass them to the gastrovascular cavity
what are gland cells?
cells that discharge enzymes to begin extracellular digestion; used by polyps
extended mouth edge
manubirum
Unlike higher animals, Cnidarian
nerve nets have neurotransmitters on
____ ____
both sides
what are the five classes of cnidaria?
anthozoa, staurozoa, scyphozoa, cubozoa, and hydrozoa
these are the derived traits of what class?
-velum in medusae
-medusae produced by lateral budding and endocodon
hydrozoa
these are the derived traits of what class?
-complex eyes
-velarium
-boxlike medusa body
cubozoa
these are the derived traits of what class?
-strobilation
scyphozoa
these are the derived traits of what class?
-creeping planula without cilia
staurozoa
these are the derived traits of what class?
-gut with septal filaments
-siphonoglyph
-anthozoan pharynx
-hexaradial and octaradial symmetry
anthozoa
what are the ancestral traits of the classes within phylum cnidaria?
-mouth surrounded by solid tentacles
-planula larva
-cnidocytes
-radial, polypoid body form
feeding polyps which are tubular, bottle-shaped, or vase-like and form a circle of tentacles surrounding mouth
hydranths
difference between thecate and athecate hydranth?
protective cup, naked polyp
what is a gonangium?
reproductive polyp
what does a velum do?
partly closes the bell and aids in swimming
what are the four types of polyps of the Man o War?
feeding, reproduction, defense, and buoyancy
what is the difference between monoecious and dioecious species?
monoecious means asexual production (produces both female and male)
dioecious means that two organisms create both
what does protandrous mean?
producing sperm first and eggs later
A grouping used by scientists to refer to all multicellular animals is
porifera.
opisthokont.
protozoan.
metazoan
metazoan
Select all of the following that describe choanocytes.
They are flagellated collar cells
They maintain a current of water through the canals of the sponge
They can trap and phagocytize food particles
They form the pinacoderm
They secrete spicules and the collagen that forms spongi
They are flagellated collar cells
They maintain a current of water through the canals of the sponge
They can trap and phagocytize food particles
In sponges, the pinacoderm
is a layer of cells containing incurrent pores.
is an opening that acts as an incurrent siphon.
is the opening at the tip of the sponge where sperm and egg cells are released during reproduction.
is a large cavity lined with choanocytes
is a layer of cells containing incurrent pores.
Incoming water enters a sponge through
oscula.
ascon.
spongocytes.
dermal pores.
dermal pores.
In a syconoid sponge, small lateral openings called Blank______ let water into the radial canals from the incurrent canals.
ostia
oscula
prosopyles
stolons
prosopyles
______ are tubular cells that form pores, while Blank______ are ameboid cells in the mesohyl with various functions.
Porocytes; archaeocytes
Pinacocytes; porocytes
Archaeocytes; choanocytes
Choanocytes; pinacocytes
Porocytes; archaeocytes
Sponge cells that can phagocytize food particles and differentiate into other cell types like spongocytes are called ____
archaeocytes
Select all of the following that describe archaeocytes.
They differentiate into more specialized cells.
They are phagocytes.
They form the external covering.
They are ameboid cells.
They differentiate into more specialized cells.
They are phagocytes.
They are ameboid cells.
is the development of entocodon layer in the hydrozoan medusae stage representative of triploblasty?
this is heavily debated. the origins of the entocodon seem to be ectodermal instead of mesodermal, so it is unclear whether or not they are triploblaslts
what are the five phylum that are the first animals to exhibit bilateral symmetry and a body organization more complex than cnidarians?
Acoelomorpha, Platyhelminthes, Nemertea,
Gastrotricha, and Ciliophora
Rotifers and acanthocephalans are lophotrochozoans but are
______
pseudocoelomate
acoelomorphs (phylum) have
no gut and a radial arrangement of nerves
which phylum has an external body covering called a neodermis with cellular ciliated epidermis?
platyhelminthes
– Have flame cells which are cupshaped structures that have flagella
extending from the surface
– Beating flagella drive fluids down
collecting ducts and through
delicate interlaced projections
– Wall of the duct bears folds or
microvilli to resorb ions and
molecules
– Majority of metabolic wastes
removed by diffusion across the
wall
– The collecting ducts join and
empty at nephridiopores to regulate water
flatworms
which class?
Mostly free-living and range
from 5 mm to 50 cm long
* Lives under objects in marine,
freshwater and terrestrial habitats
* combine creeping
with ciliary movements while
very small planaria swim by cilia
* Others move by gliding over a
slime track secreted by marginal
adhesive glands and using
rhythmical muscular waves that
pass backwards from the head
turbellaria
what are those from class trematoda also called?
flukes
explain the life cycle of the common liver fluke
Miracidium - Free living
* Sporocyst - Snail
* Redia - Snail
* Cercaria - Free living
* Metacercaria - Plant / Animal
which phylum?
Microscopic, aquatic animals
(inhabiting sediments of marine and
freshwater environments) with a
head, neck, and trunk
* Numerous adhesive glands are
present
* Marine species are generally
hermaphroditic
* Parthenogenesis (laying unfertilized
eggs) is common in freshwater
species
* Protonephridia possess a single
flagellum instead of cilia found in
flame cells
gastrotricha
(laying unfertilized
eggs
Parthenogenesis
possess a single
flagellum instead of cilia found in
flame cells
Protonephridia
what are the 9 most known phylum of animals? remember (pcpnaamec)
porifera, cnidaria, platyhelminthe, nematoda, annelida, arthropoda, mollusca, echinodermata, and chordata
have ducts that empty into excretory bladder that leads to the outside
via a terminal pore
trematodes
have two main excretory canals on each side that are continuous along
the length of the worm and join on the last segment and opens to the terminal pore
Cestodes
explain the nervous system of flatworms
Most primitive flatworm nervous system called subepidermal nerve plexus
resembles the nerve net of cnidarians
* Also have one to five pairs of longitudinal nerve cords under the muscle layer
* Freshwater planarians have one ventral pair of nerve cords forming a ladder-type
pattern and the brain is a bilobed ganglion anterior to the ventral nerve cords
beef tapeworm life cycle
Onchosphere
* Found in egg
* Digestive enzymes release it
*Cysticerus
* Bladder worm
* Form fluid filled bladder
* Encyst in muscle
Taenia solium
* Pork Tapeworm
* Cysticercosis
Microscopic, aquatic animals
(inhabiting sediments of marine and
freshwater environments) with a
head, neck, and trunk
* Numerous adhesive glands are
present
* Marine species are generally
hermaphroditic
* Parthenogenesis (laying unfertilized
eggs) is common in freshwater
species
* Protonephridia possess a single
flagellum instead of cilia found in
flame cells
which phylum?
Phylum Gastrotricha
possess a single
flagellum instead of cilia found in
flame cells
Protonephridia
(laying unfertilized
eggs) is common in freshwater
species
Parthenogenesis
which 6 phylum are lophotrochozoan?
platyhelminthes, gastrotricha, gnathifera, micrognathozoa, rotifera, acanthocephala
which phylum is not lophotrochozoan?
mesozoa
(jawed worms)
– Found mostly in interstitial
spaces of very fine sand,
sediment and silt from the coasts
to the deep sea.
– Can endure very low oxygen and
live in association ciliates,
tardigrades and worms
– Feed by scraping bacteria and
fungi from the substrate with
paired jaws on the pharynx
– Acoelomate with no circulatory
system but use diffusion for
excretion and gas exchange
– Protandric or simultaneous
hermaphrodite that can cross fertilize internally forming single
zygote
Phylum Gnathostomulida
Mostly small animals living
interstitially with a two-part head,
thorax and abdomen leading to short
tail
– Has dorsal plates but no ventral ones
and use cilia to move with a ventral
adhesive pad that produce glue
– Have three pairs of complex jaws with
mouth leading to simple gut and anus
– Has protonephridia but reproductive
system is not well understood
Phylum Micrognathozoa
Tripoblastic, bilateral, unsegmented,
pseudocoelomates
– Complete digestive system, regionally
specialized
– Anterior end often has a ciliated organ
called a corona
– Posterior end with toes and adhesive
glands
– Well-developed cuticle
– Protonephridia with flame cells
– Males generally reduced in numbers or
absent; parthenogenesis common
Phylum Rotifera
explain the Rotifera Life Cycle
Amitic eggs
diploid; mitosis
* Mitic eggs
haploid; meiosis
changes depending on environmental stimuli (fall rain, winter)
s are endoparasites in the
intestinal tract of vertebrates
* The body of an adult is elongate and
composed of a short anterior proboscis, a neck
region, and a trunk
* The retractable proboscis provides the means
of attachment in the host’s intestine
* Tegument – absorb food
* Dioecious
* have unique embryo
selective apparatus system
Phylum Acanthocephala
Sperm is ejected into female genital duct
and into the pseudocoel
– Embryos are sorted and separated
according to size and condition
– Shelled embryos are released in the feces
of host and await entry to intermediate
host
selective apparatus system
a (middle animals)
– Considered a “missing link”
between protozoa and metazoa
– Usually minute, ciliated, and
wormlike animals that live as
parasites or symbionts in
marine invertebrates
– Arranged in two layers of 20-30
cells not related to animal germ
layers of metazoans
* Live in kidneys of benthic
cephalopods
* Adults called vermiforms and are
long and slender
* Asexual reproduction consists of a
multinucleated mass called a
plasmodium that give rise to males
and females
Phylum Mesozoa
what are lophophores? (function)
s have a crown of ciliated tentacles that are used in food capture
and respiration
– Cavity inside the lophophore is part of the coelom and filled with coelomic
fluid
– Thin ciliated walls act as respiratory surface for gas exchange
– Lophophores normally extended but can be withdrawn for protection
which phylum use lophophores?
ectoprocta, brachiozoa, phoronida
Members of this phylum live on
the mouthparts of the claw
lobster
– 0.35 mm long (0.10 mm wide)
* Dwarf males emerge and seek
out another female symbiont
– During lobster molt
* Free swimming individuals seek
another host
Phylum Cycliophora
Similar to Platyhelminthes, but can be
much larger
– Have fluid filled sac, primitive coelom
* Prey on invertebrates, which they capture
with a unique probosis held in a sheath
called a rhynchocoel
* They have a complete digestive tract
(mouth and anus)
* Blood-vascular system
– Primitive circulatory system
– Two lateral blood vessels
* Dioecious
* Fertilization results in a helmet shaped,
ciliated pilidium larva
Phylum Nemertea
In a typical cnidarian life cycle, a newly formed zygote develops into a motile _____ larva, which then settles onto a hard surface to develop into a _____.
planula, polyp
Tiny organelles contained within cnidocytes are called
cnidae
The tentacle cavity communicates with the gastrovascular cavity; extracellular digestion occurs in the gastrovascular cavity and intracellular digestion occurs in the gastrodermis
Hydra
Digestion begins in the mouth, which faces upward into the water column; a digestive broth is passed to the gastrovascular cavity, where intracellular digestion occurs in the cells lining it
colonial hydrozoan polyps
Digestion begins in the mouth, which faces downward at the end of a manubrium; a digestive broth is passed to the gastrovascular cavity, where intracellular digestion occurs in the cells lining it
hydromedusae
The diffuse nervous system of cnidarians can best be described as a
nerve net
What type of cnidarian structure can be described as a tiny capsule composed of a material similar to chitin containing a coiled filament that may bear tiny barbs?
nematocyst
which class?
The polyp stage is usually asexual.
Most are colonial in form.
Some lack a medusa stage in the life cycle.
hydrozoa
The difference between thecate and athecate hydroid polyp forms is the presence of a
protective cup formed by an extension of the perisarc.
What is a hypostome?
A conical protuberance upon which the mouth is situated, found in hydras
In hydroid colonies, polyps may be
______ indicating that the perisarc creates a protective cup around the polyp and functions in protection, or _____ when there is no such protective cup.
thecate, athecate
Members of what cnidarian class have the following characteristics:
a medusa stage ranging from 2 cm to 2 m in diameter, a bell that lacks a velum and can vary from a shallow saucer shape to a deep helmet or goblet shape, and sense organs called rhopalia?
Scyphozoa
which class?
An adhesive disc that attaches to objects on the ocean floor
A polyp that resembles a medusa, with eight arms surrounding the mouth
A solitary stalked polyp body form
staurozoa
which class?
Each rhopalium contains six eyes.
The base of a tentacle is differentiated into a flattened, tough blade called a pedalium.
The edge of the subumbrella turns inward to form a velarium.
cubozoa
which class?
The gastrovascular cavity is partitioned by septa.
They can be solitary or colonial.
Many forms produce a skeleton for support.
anthozoa
What organism is best described as a relatively large polyp with a crown of tentacles arranged in one or more circles around the mouth of a flat oral disc?
sea fan
Portuguese man-o-war
sea anemone
cubozoan
sea anemone
Biradial marine animals that typically use eight rows of cilia for locomotion are members of what taxonomic group?
(phylum)
Ctenophora
In Cnidaria, Blank______ have expanded locomotor and sensory capabilities.
medusae
Protective cells that can swell and form a protective sheath around a turbellarian are called
rhabdites
What phylum is distinguished by a cylindrical, invaginable proboscis?
Acanthocephala
Relatively small planktonic marine predators that have torpedo-shaped bodies and mouths bearing sickle-shaped bristles on each side make up what phylum?
Chaetognatha
Acanthocephalans are dioecious.
T/F
True
which phylum?
Parasites
Symbionts
Two-layered body
Ciliated worm-like exterior
mesozoans
which phylum?
Cilia around mouth
U-shaped gut with anus
cycliophora
which phylum?
Ciliary feeders
Solitary or colonial sessile organisms
most less than 0.5mm in size
encrust firm surfaces
colony builders (zooid)
entoprocta
The crown of tentacles in the Urnatella and Loxosomella is called the
calyx
Small, worm-like marine organisms that secrete a leathery or chitinous tube in which they live
They live in a leathery or chitinous tube.
They are marine organisms.
Their lophophore creates water current.
They are worm-like animals.
Phylum?
phoronida
which phylum?
They are bottom dwelling species.
They prefer shallow water marine habitats.
They have a fleshy stalk called a pedicel.
It contains the living form called Lingula.
It was most prominent and diverse in the Paleozoic and Mesozoic.
brachiopods
It contains the living form called Lingula.
It was most prominent and diverse in the Paleozoic and Mesozoic.
It contains the ribbon worms.
Nearly all are marine.
Extracellular in a complete digestive tract.
which phylum?
nemertea
The ciliated epidermis and flame cells in nemerteans show that they were once taxonomically aligned with the Phylum
Platyhelminthes
