Exam #3 Study Guide Flashcards
which phylum?
common shared features include unusual ribbon of teeth called radula, large muscular foot or tentacles for movement, and mantle for respiration and cell secretion
phylum ecdyzoans
phylum annelids
phylum mollusca
phylum nemotoda
phylum mollusca
what kind of circulatory system to most cephalopods have?
closed
this class of mollucs can use head and foot into the mantle cavity to create jet propulsion
class cephalopods
class gastropods
class caudofoveata
class solenogasters
class cephalopods
this class of molluscs can withdraw head and food into the mantle cavity and hide into the shell
class cephalopods
class gastropods
class caudofoveata
class solenogasters
class gastropods
are most molluscs dioecious or monoecious?
dioecious, some are hermaphroditic
what kind of larva do molluscs have?
trocophore
this kind of shell is from fossils and is one plane (flat) in molluscs?
planospiral shell
conspiral shell
planospiral shell
what kind of shell is shifted over the body for better weight distribution in molluscs?
conspiral shell
planospiral shell
conspiral shell
what kind of circulatory systems do most gastropods have?
open
what kind of skeleton do most gastropods have?
mushy skeleton
boney skeleton
hydraulic skeleton
muscular skeleton
hydraulic skeleton
this class in phylum mollusca has a single shell consisting of two hinged valves, an umbo, and a mantle used for jet propulsion
class gastropoda
class bivalvia
class cephalopoda
class bivalvia
what kind of larval stage do bivalves have?
trocophore
locopohore
glochidia (parasitic)
glochidia (parasitic)
the giant clam, rock scallop, and geoduck are all in the class:
class gastropoda
class bivalvia
class cephalopoda
class bivalvia
the squid, octopuses, cuttlefish, and nautiluses are all in the class:
class gastropoda
class bivalvia
class cephalopoda
class cephalopoda
the marine snails, limpets, slugs, whelks, conches, periwinkle, sea slugs, sea hares, and sea butterflies are all in the class:
class gastropoda
class bivalvia
class cephalopoda
class gastropoda
this class of molluscs are known for a modified foot into a circle of tentacles or arms and a head in line with the visceral mass
class gastropoda
class bivalvia
class cephalopoda
class cephalopoda
this class uses jet propulsion by using muscles of the mantle compressing water within the mantle cavity and siphon:
class gastropoda
class bivalvia
class cephalopoda
class cephalopoda
what kind of circulatory system does class cephalopods have?
closed
this class of molluscs uses spermatophores or packets of sperm to transfer to the female:
class gastropoda
class bivalvia
class cephalopoda
class cephalopoda
this class of mollusc is sometimes seen using protandry in some monoecious species:
class gastropoda
class bivalvia
class cephalopoda
class gastropodaw
which two classes of molluscs has a veliger larval stage?
class gastropoda
class bivalvia
class cephalopoda
class gastropoda
class bivalvia (also has spat)
which phylum is known for a metameric body, sophisticated nervous system for fine motor control, and injury to part will not be fatal to the whole?
phylum ecdyzoans
phylum annelids
phylum mollusca
phylum nemotoda
phylum annelids
this group of annelids are mobile, active worms often found in marine environments where they swim or burrow:
errantia
sedentaria
errantia
this group of annelids are stationary, living in tubes or burrows where they engage in less movement:
errantia
sedentaria
sedentaria
what is the sister group to the annelids?
hirudinida
clitellata
sipuncula
sipuncula
what two classes are in clade clitellata and lack parapodia and are hermaphroditic?
class oligochaeta
class hiuridinea
class clitellata
class sipuncula
class oligochaeta
class hiruidnea
this class includes earthworms:
class oligochaeta
class hiuridinea
class clitellata
class sipuncula
class oligochaeta
this class includes leeches:
class oligochaeta
class hiuridinea
class clitellata
class sipuncula
class hiruidnea
are those in class hiruidnea monoecious or dioecious?
monoecious, sexual reproduction on ly
this phylum is known for having a cuticle that can molt using ecdysis:
phylum ecdyzoans
phylum annelids
phylum mollusca
phylum nemotoda
phylum ecdyzoans
ecdyzoans can have different body plans (psudeocoelemate/ coelomate)
t/f
true
which members of ecdyzoa are pseudococlomate?
priapuldia
nematoda
nematomorpha
kinohyncha
nematoda
nematomorpha
kinohyncha
which members of ecdyzoa are coelomate?
priapuldia
nematoda
nematomorpha
kinohyncha
priapuldia
this phylum has both dorsal and ventral nerves:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum nemotoda
this phylum uses copulatory spicules to reproduce:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum nemotoda
this phylum only has longitudinal muscles in the body wall:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum nemotoda
ascaris lumbriocodes, nectra americanus, trichinella spiralis, and wuchereia spp, are all annelid parasites.
t/f
false, they’re nematode parasites
this phylum is known for free-living adult phase of life cycle achieves sexual maturity:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum nematomorpha
this phylum is known for “velvet worms” and slime glands on each side of the body cavity open on oral papillae:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum onychophora
what is tagmatization?
specialization of body regions
this phylum is known for very small organisms that can use cryptobiosis by dehydrating 82% to 3% of water:
phylum nematoda
phylum nematomorpha
phylum onychophora
phylum tardigrada
phylum tardigrada
what shape of muscles do annelids use to move?
circular: flattens
longitudinal: expands
Respiration in most gastropods is performed by a ______.
osphradium
proboscis
ctenidium
radula
ctenidium
Molluss called ______ are mostly sedentary filter feeders and have two shells, no head, and no radula.
bivalves
cephalopods
gastropods
bivalves
______ have the most elaborate nervous and sensory system of all of the molluscs.
bivalves
cephalopods
gastropods
cephalopods
The head of an annelid is the first true segment.
t/f
false
oligochaeteta
hirudinida
polychaetes
match with the following:
leeches
marine worms
earthworms
oligocaeteta: earthworms
hirudinida: leeches
polychaetes: marine worms
The end of the excretory organ that opens into a coelomic compartment in the polychaete body is the _______.
nephrostome
nephridiopore
nephrocoel
nephrostome
Select all of the following that describe oligochaetes.
They lack setae.
Some are parasitic.
Most are terrestrial or freshwater.
Most live in marine habitats
They lack parapodia.
Some are parasitic.
Most are terrestrial or freshwater.
They lack parapodia.
In most earthworms, each segment bears pairs of ______ which anchor the body during locomotion.
radioles
setae
clitella
parapodia
setae
What is the “brain” of an oligochaete?
Pair of cerebral ganglia
Ventral nerve cord
Giant axons
Nerve ring
Pair of cerebral ganglia
Leeches differ from other annelids in that they possess
less specialization
setae
distinct coelomic compartments
a fixed number of segments
a fixed number of segments
a ____ is a mucoid mass that extends to the stomach of gastropods and contains trapped food particles and is rotated by cilia
style sac
radula
mantle cavity
protostyle
protostyle
members of the class cephalopoda are the only molluscs that possess closed circulatory systems
t/f
true
mollucs can be characterized by:
-jointed appendages and radial symmetry
-trocophore larvae and they are lophotrochozoans
-a water vascular system and tube feet
-segmented bodies and chitinous exoskeletons
trocophore larvae and they are lophotrocozoans
a clittellum is present in the members of the subclasses:
polychaeta
hirudinea and oligochaeta
gastropoda and bivalvia
cephalodpoda and scaphopoda
hirudinea and oligochaeta
the formation of a reproductive individual that differs from a non-reproductive individual is:
parthenogenesis
metamorphosis
epitoky
budding
epitoky
which of the following phyla are not pseudocoelomate?
nematoda
rotifera
polychaeta
nematomorpha
polychaeta
mictic eggs are diploid
t/f
false
the _____ cells are specialized by excretory cells found in nematodes
nephridia
renette
protonephridida
renal
renette
members of the phylum nematomorpha are commonly called the ____ worms
horsehair
gordian
ribbon
both a and b
both a and b
what type of body cavity is found in annelids?
acoelmate
pseudocoelmate
coelmate
none of the above
coelomate
which of the following is a characteristic feature of oligochaetes?
presence of parapodia
well-developed head
clitellum
ability to swim
clitellum
the primary mode of locomotion in polychaetes is through the use of:
cilia
segmented muscles
parapodia
hydrostatic pressure
parapodia
which class of molluscs is characterized by a well-developed head and tentacles?
bivalvia
cephalopoda
gastropoda
polyplacophora
cephalopoda
in molluscs, the mantle is responsible for:
protection and respiration
circulation
digestion
nervous coordination
protection and respiration
which of the following organisms belongs to phylum nematoda?
earthworm
horsehair worm
ascaris
planaria
ascaris
the excretory system in nematodes primarily consists of:
flame cells
renette cells
nephridia
malpighian tubules
renette cells
the presence of a coelom in annelids allows for:
greater flexibility in movement
improved nutrient absorption
development of complex organ systems
all of the above
all of the above
which of the following statements about molluscs is true?
they are exclusively marine animals
all molluscs have a shell
molluscs have a muscular foot for locomotion
they lack a circulatory system
molluscs have a muscular foot for locomotion
the class polychaeta is distinguished by:
presence of parapodia for locomotion
lack of segmentation
absence of chaetae (bristles)
direct development without a larval stage
presence of parapodia for locomotion
in members of the class oligochaeta, the clitellum is primarily used for:
sensory perception
excretion
reproduction
respiration
reproduction
leeches (class hirudinea) differ from the other annelids in that they:
lack setae (bristles)
have a reduced coelum
use suckers for locomotion and feeding
all of the above
all of the above
gastropods exhibit torsion during development, which results in:
coiling of the shell
twisting of the body so that the anus is located near its head
formation of the radula
development of a siphon for filter feeding
twisting of the body so that the anus is located near its head
which of the following features is typical of class bivalvia?
a radula used for feeding
two hinged shells held together by adductor muscles
a well-developed head with sensory organs
jet propulsion as the primary mode of locomotion
two hinged shells held together by adductor muscles
members of the class cephalopoda differ from other molluscs by having:
a closed circulatory system
a muscular foot used for burrowing
a mantle that secretes a calcareous shell
a larval stage that undergoes torsion
a closed circulatory system
which of the following is a characteristic feature of nematodes?
segmented body plan
pseudocoelom
true coelom
external skeleton made of calcium carbonate
pseudocoelom
in the phylum nematomorpha, the adult stage is:
free-living in aquatic environments
parasitic in arthropods
capable of asexual reproduction
non-parasitic and terrestrial
free-living in aquatic environments
which of the following statements about tardigrades is true?
they are pseudocoelomates like nematodes
they undergo cryptobiosis to survive extreme conditions
they are primarily parasitic on vertebrates
they have jointed appendages and an exoskeleton
they undergo cryptobiosis to survive extreme conditions
Polychaetes are primarily terrestrial annelids that lack parapodia.
T/F
False
(Polychaetes are mostly marine and have parapodia for locomotion.)
Leeches (class Hirudinea) have segmented bodies but lack setae (bristles).
T/F
True
(Leeches are segmented annelids but do not have setae like other annelids.)
All molluscs have a radula for feeding.
T/F
False
(Bivalves do not have a radula, while most other molluscs do.)
Cephalopods possess a closed circulatory system, unlike most other molluscs.
T/F
True
Cephalopods possess a closed circulatory system, unlike most other molluscs.
Nematodes (roundworms) are coelomates, meaning they have a body cavity completely lined with mesoderm.
T/F
False
(Nematodes are pseudocoelomates, not coelomates.)
Which of the following statements correctly compares the circulatory systems of annelids and molluscs?
a.) Annelids possess an open circulatory system, while molluscs have a closed circulatory system.
b.) Both annelids and molluscs have open circulatory systems.
c.) Annelids have a closed circulatory system, while molluscs have an open circulatory system.
d.) Both annelids and molluscs have closed circulatory systems.
c.) Annelids have a closed circulatory system, while molluscs have an open circulatory system.
In which of the following ways do polychaetes differ from oligochaetes?
a.) Polychaetes typically have fewer setae than oligochaetes.
b.) Polychaetes usually exhibit a segmented body with parapodia, while oligochaetes do not.
c.) Polychaetes are exclusively freshwater species.
d.) Oligochaetes lack a clitellum, while polychaetes possess one.
b.) Polychaetes usually exhibit a segmented body with parapodia, while oligochaetes do not.
Annelids and nematodes are both classified as protostomes, indicating they share a more recent common ancestor than with deuterostomes.
T/F
True
Which of the following groups is considered a sister group to molluscs based on phylogenetic relationships?
a.) Arthropods
b.) Annelids
c.) Echinoderms
d.) Nematodes
b.) Annelids
During development, which larval stage is typically observed in both annelids and molluscs?
a.) Planula
b.) Trochophore
c.) Veliger
d.) Zygote
b.) Trochophore
Nematodes undergo direct development, meaning they do not have a larval stage.
T/F
True
Which of the following describes the developmental process unique to gastropods?
a.) Metamorphosis
b.) Torsion
c.) Parthenogenesis
d.) Schizocoely
b.) Torsion
Which of the following is a distinguishing feature of bivalves compared to other molluscs?
a.) Presence of a radula
b.) Body divided into three main parts: head, foot, and visceral mass
c.) Two-part shell (valves) and filter-feeding mechanism
d.) Ability to change color for camouflage
c.) Two-part shell (valves) and filter-feeding mechanism
How do the body plans of nematodes and annelids differ?
a.) Nematodes have a segmented body; annelids do not.
b.) Annelids have a pseudocoelom; nematodes have a true coelom.
c.) Nematodes have a non-segmented body plan; annelids are segmented.
d.) Both have identical body plans.
c.) Nematodes have a non-segmented body plan; annelids are segmented.
Molluscs and annelids share a more recent common ancestor with arthropods than with echinoderms
T/F
True
Which of the following phyla is most closely related to annelids based on molecular phylogenetic studies?
a.) Mollusca
b.) Arthropoda
c.) Onychophora
d.) Nematoda
c.) Onychophora
Which developmental feature is unique to the life cycle of polychaetes?
a.) Formation of a trochophore larva
b.) Metamorphosis into a juvenile
c.) Direct development without a larval stage
d.) Torsion of the body
a.) Formation of a trochophore larva
The process of ecdysis is primarily associated with the development of annelids.
T/F
False
Which stage in the life cycle of molluscs follows the trochophore larva?
a.) Veliger larva
b.) Adult
c.) Egg
d.) Planula
a.) Veliger larva
all of the following are unique to the molluscs except one. select the exception
mantle
shell
visceral mass
head-foot
shell
______ is developmental process that occurs in gastropods and results in a 180 degree counterclockwise twisting of the visceral mass and mantle cavity.
gastrulation
epiboly
involution
torsion
torsion
a ______ is rotated by cillia and extends into the stomach of bivalves. it produces a mucoid mass containing trapped food particles.
protostyle
umbo
crystalline style
gastric shield
crystalline style
which type of cephalopod possesses an external shell?
cuttlefish
nautilus
squid
octopus
nautilus
which of the following is generally accepted as the prevailing explanation behind the evolution of intelligence in cephalopods?
their complex social structure
the fact that they typically live long lives
living as active predators as well as actively avoiding predators
the pressures exerted by living in both marine and freshwater environments
living as active predators as well as actively avoiding predators
aquatic molluscs excrete _____, whereas terrestrial molluscs secrete ______.
uric acid; ammonia
ammonia; uric acid
ammonia; oxygen
oxygen; ammonia
ammonia; uric acid
members of the class cephalopoda and gastropoda are the only mollucs that possess a closed circulatory system.
t/f
false; only cephalopoda
nuchal organs are chemoreceptors found in the head of a polychaeta worm
t/f
true
an ocean dwelling worm in the errantia group (Nerius) would have a clitellum.
t/f
false, errantia is outside of clitellada
the main propulsive structure(s) in the circulatory system of an earthworm is (are)
capillaries
dorsal and ventral aorta
seminal vesicles
the typhlosole
dorsal and ventral aorta
the specialization of body regions in segmented animals is called:
tagmatization
metamerism
cephilization
eutely
tagmatization
a distinctive feature of members of the subclass hirudinea is:
parapodia
anterior and posterior suckers
tentacles
palps
anterior and posterior suckers
pearl formation may occur in bivalves when an irritant becomes lodged between the shell and the mantle. the mantle secretes nacre around the irritant, gradually forming a pearl.
t/f
true
A nonliving external layer secreted by the epidermis of many protostomes is called a
ectoderm
mesoderm
cuticle
ecdysis
cuticle
the most common worm parasite in the United States is the
intestinal roundworm
pinworm
whipworm
tapeworm
pinworm
The members of Phylum ______ are caterpillar-like in appearance, range 0.5 to 15cm in length, and inhabit tropical and subtropical regions.
priapuldia
onychopora
kinorhyncha
loricifera
onychopora
Which of the following is a characteristic of oligochaetes but not polychaetes?
a.) Presence of parapodia
b.) Trochophore larva
c.) Clitellum for reproduction
d.) Segmentation
c.) Clitellum for reproduction
Which type of feeding mechanism is most commonly found in bivalve molluscs?
a.) Radula scraping
b.) Suspension feeding
c.) Predation using beak-like structures
d.) Absorbing nutrients through the skin
b.) Suspension feeding
In nematodes, the body cavity is a pseudocoelom, which:
a.) Is lined entirely by mesoderm
b.) Is filled with blood
c.) Acts as a hydrostatic skeleton
d.) Is a true coelom
c.) Acts as a hydrostatic skeleton
In molluscs, the nervous system is generally described as:
a.) Ladder-like with paired ventral nerve cords
b.) Decentralized with a nerve net
c.) Well-developed with a centralized brain in all species
d.) Absent in bivalves
a.) Ladder-like with paired ventral nerve cords
The hemocoel is the primary body cavity in molluscs, in which blood circulates through an open circulatory system in most species.
T/F
True. (Most molluscs, except cephalopods, have an open circulatory system.)
Nematodes undergo ecdysis, or molting, of their cuticle as they grow.
T/F
True. (Nematodes are ecdysozoans, meaning they molt their cuticle.)
Earthworms (Oligochaeta) have trochophore larvae like polychaetes.
T/F
False. (Earthworms develop directly without a trochophore larva.)
All molluscs use a radula for feeding.
T/F
False. (Bivalves, for example, are filter feeders and lack a radula.)
Which structure in molluscs is homologous to the parapodia in polychaetes?
a.) Foot
b.) Mantle
c.) Visceral mass
d.) Radula
a. (The foot of molluscs serves a similar locomotory function as the parapodia of polychaetes.)
In terms of phylogeny, what is a major difference between annelids and nematodes?
a.) Annelids have a true coelom, while nematodes are pseudocoelomates.
b.) Nematodes undergo spiral cleavage, while annelids undergo radial cleavage.
c.) Annelids are ecdysozoans, while nematodes are lophotrochozoans.
d.) Nematodes have a closed circulatory system, while annelids do not.
a. (Annelids are coelomates, whereas nematodes are pseudocoelomates.)
Which of the following groups contains members that utilize a hydrostatic skeleton for movement?
a.) Molluscs
b.) Polychaetes
c.) Nematodes
d.) All of the above
d.
What is a shared feature between tardigrades and nematodes in terms of their body structure?
a.) Both are coelomates.
b.) Both possess a cuticle that they molt.
c.) Both have segmentation.
d.) Both have parapodia for movement.
b
Polychaetes are primarily terrestrial annelids that rely on direct development.
T/F
False. (Polychaetes are primarily marine and have trochophore larvae.)
The excretory system of earthworms (oligochaetes) involves specialized structures called:
a.) Nephridia
b.) Malpighian tubules
c.) Flame cells
d.) Antennal glands
a. nephridia
Which of the following is responsible for the buoyancy control in cephalopods?
a.) Siphon
b.) Radula
c.) Mantle
d.) Gas-filled chambers in the shell (e.g., in nautilus)
d.) Gas-filled chambers in the shell (e.g., in nautilus)
In nematodes, waste products are primarily excreted through:
a.) Malpighian tubules
b.) Protonephridia
c.) Renette cells
d.) Nephridia
c.) Renette cells
Which type of mollusc uses a crystalline style for digestion?
a.) Cephalopods
b.) Gastropods
c.) Bivalves
d.) Polyplacophora
c.) Bivalves
The body cavity of a mollusc is known as the:
a.) Pseudocoelom
b.) Hemocoel
c.) Coelom
d.) Gastrovascular cavity
c.) Coelom
Which of the following groups is most closely related to molluscs?
a.) Annelids
b.) Arthropods
c.) Cnidarians
d.) Echinoderms
a.) Annelids
Which of the following features is not unique to annelids?
a.) Segmentation
b.) Parapodia
c.) Clitellum
d.) Nephridia
d.) Nephridia
Polychaete worms primarily move through:
a.) Undulating movements of the body wall
b.) Contractions of the muscular foot
c.) Siphon propulsion
d.) Using their parapodia as paddles
d.) Using their parapodia as paddles
Which of the following groups of molluscs typically lacks a radula?
a.) Gastropods
b.) Cephalopods
c.) Bivalves
d.) Polyplacophorans
c.) Bivalves
The crystalline style in bivalves functions in:
a.) Grinding food particles
b.) Digestion and enzyme release
c.) Waste excretion
d.) Sensory perception
b.) Digestion and enzyme release
Gas exchange in polychaetes primarily occurs through:
a.) Their parapodia
b.) Gills located in the mantle cavity
c.) Diffusion through the body surface
d.) Tracheal systems
a.) Their parapodia
Which sensory structures are responsible for chemoreception in polychaetes?
a.) Statocysts
b.) Nuchal organs
c.) Sensory tentacles
d.) Compound eyes
b.) Nuchal organs
The excretory organs in earthworms are called:
a.) Flame cells
b.) Protonephridia
c.) Nephridia
d.) Renette cells
c.) Nephridia
Which class of annelids is characterized by the presence of a clitellum and direct development (no larval stage)?
a.) Polychaeta
b.) Hirudinea
c.) Oligochaeta
d.) Pogonophora
c.) Oligochaeta
Which clade within the Ecdysozoa is known for having a pseudocoelom and cuticle molting?
a.) Arthropoda
b.) Nematoda
c.) Annelida
d.) Mollusca
b.) Nematoda
Which of the following phyla is considered pseudocoelomate?
a) Arthropoda
b) Annelida
c) Nematoda
d) Mollusca
c) Nematoda
What function does the hydrostatic skeleton serve in nematodes?
a) It helps in locomotion by providing buoyancy.
b) It allows for muscle contractions to transmit force through fluid.
c) It supports the digestive system.
d) It protects against desiccation.
b) It allows for muscle contractions to transmit force through fluid.
Which of the following parasitic nematodes is known to block lymphatic vessels, causing elephantiasis?
a) Ascaris lumbricoides
b) Necator americanus
c) Wuchereria spp.
d) Trichinella spiralis
c) Wuchereria spp.
Which characteristic is unique to nematodes and contributes to their muscle coordination?
a) Presence of a coelom
b) Lack of motile cilia or flagella
c) Lack of circular muscles
d) Ability to regenerate
c) Lack of circular muscles
Panarthropoda is a monophyletic group that includes Onychophora, Tardigrada, and Arthropoda.
T/F
True
In nematodes, amphids are a pair of sensory organs found near the posterior end of the body.
T/F
False (Amphids are located near the anterior end of the body.)
Trichinella spiralis causes trichinosis, and infection occurs by consuming poorly cooked pork.
T/F
true
The phylum Nematomorpha contains parasitic worms that infect arthropods.
T/F
True (As juveniles, they are parasitic in arthropods but are free-living as adults.)
Which of the following is a characteristic of the Phylum Onychophora?
a) They are primarily marine.
b) They have a segmented body with paired appendages.
c) They are commonly known as velvet worms.
d) They lack a digestive system.
c) They are commonly known as velvet worms.
In Nematoda, which structures are involved in sensory perception?
a) Ocelli
b) Amphids and phasmids
c) Statocysts
d) Lateral line systems
b) Amphids and phasmids
Which of the following statements about nematode reproduction is true?
a) They are hermaphroditic.
b) Fertilization is usually external.
c) They can produce between 100 and 100,000 eggs.
d) They do not have distinct male and female forms.
c) They can produce between 100 and 100,000 eggs.
Nematodes have both circular and longitudinal muscles, allowing for complex movement.
T/F
False (They only have longitudinal muscles.)
Kinorhynchs are characterized by a retractile proboscis and a spiny neck.
T/F
True
Parasitic nematodes usually undergo a direct developmental cycle without any free-living juvenile stages.
T/F
False (They may have free-living juvenile stages requiring intermediate hosts.)
The phylum Priapulida is characterized by having a distinct head and a pair of antennae.
T/F
False (They lack a distinct head and have a eversible pharynx for feeding.)
