Chapter 31 Flashcards
Animals share a common ___ ancestor
choanoflagellate
Sponges are assigned to a ___ group, ___ due to asymmetry and simple body plans
basal group, Parazoa
Animals with true tissues are classified as
Eumetazoa
Sponges are apart of phylum
Porifera
___ are aquatic feeders, primarily marine
Poriferans
Characteristics of Sponges
- Flagellated collar cells
- Larvae have flagella; adults are sessile
- Cells do not form true tissues
- Water circulates in three types of canal systems (Asconoid, Syconoid, Leuconoid)
- Fibrous part of the sponge skeleton consists of a form of spongin
- Gas exchange and excretion depend on diffusion
- Sponges do not have specialized nerve cells
Sponges reproduce by ___ and ___
Sponges reproduce by fragmentation and sexually
most sponges are ___
hermaphrodites
Three main groups of sponges
- Calcareous sponges
- Glass sponges
- Demosponges
Calcareous sponges
class: Calcarea
Skeleton either mesh or honeycomb structure
Glass sponges
class: Hexactinellidae
six ray
Demosponges
Class: Demospongiae
People sponge
Class Demospongiae
Freshwater: found in clean ponds and streams in eastern North America
Siliceous spicules with one to four rays and/or spongin fibers
Cnidarians are apart of phylum
Cnidaria
___ are mostly marine animals with radial symmetry
Cnidarians
Cnidarians have a ___ and ___ body shapes
Polyp and medusa
___ contain stinging nematocysts
Cnidocytes
Gastrovascular cavity has a single opening that serves as both ___ and ___
mouth and anus
Cnidarians are
diploblastic
Cnidarians Nerve cells form
nerve nets
Cnidarians have a ___ skeleton
hydrostatic skeleton
Cnidarian body plan: Nervous systes
Lack a Centralized nervous system
Nerve net
Medusa have more complex nervous system with sense organs
Nerve net Cnidarian Body Plan
one between the epidermis and the mesoglea and another between the gastrodermis and the mesoglea
Coral Reefs consist of
corals and red algae
one-fourth of all marine species depend on ___ ___
coral reefs
coral bleaching
stress induced loss of symbiotic algae
without their algae, corals become malnourished and die
Lophotrochozoa is a clade that includes
Flatworms, rotifers, nemerteans, mollusks, annelids and the lophophorate phyla
most Lophotrochozoa have ___ symmetry
bilateral
at least in larval stages
most lophotrochozoa are ___, have a true ___ and a ___ body plan, and exhibit ___
most lophotrochozoa are triploblastic, have a true coelom and a tube-within-a-tube body plan, and exhibit cephalization
Flatworms are a part of phylum
Platyhelminthes
flatworms are ___ with simple, bilateral symmetry
acoelomates
Flatworms have a simple nervous systes
consisting of two masses of nervous tissue (ganglia) connected to two nerve cords
Flatworm sense organs
include simple eyespots and organs of balance (statocysts)
Flatworms have a ___ cavity with only ___ opening
Flatworms have a gastrovascular cavity with only one opening, a mouth
flatworms have no organs for___
circulation or gas exchange
Four classes of Flatworms
- Class Turbellaria (Free-living flatworms)
- Class Trematoda (flukes)
- Class Monogenea (flukes)
- Class Cestoda (Tapeworms)
___ and ___ are highly adapted to and modified for their parasitic lifestyle
Flukes and tapeworms are highly adapted to and modified for their parasitic lifestyle
Trematoda
All are endoparasites
two subclasses of class trematoda
- Aspidogastrea (have only one host)
2. Digenea (have at least two hosts)
Mollusks are apart of phyllum
Mollusca
mollusks include
clams, oysters, snails ,slugs, octopods, and squids
six basic characteristics of Mollusca
- soft body
- broad, flat, muscular foot
- body organs concentrated as a visceral mass
- a pair of folds that overhangs the visceral mass forming a mantle cavity that contains gills or a lung
- a rasplike radula in the mouth region
- a reduced coelom around the heart and metanephridia; and a hemocoel
Foot of phylum Mollusca
Ventral body wall specialized for locomotion and burrowing
Mantle of phylum Mollusca
Dorsal body wall that secretes spicules, shell plates, or shells
Siphon of phylum Mollusca
rolled extension of mantle to bring water into and out of aquatic molluscs and as inhalant tube in terrestrial gastropods
Visceral Mass of phylum Mollusca
grouping of internal organs (viscera)
Mantle Cavity of phylum Mollusca
houses visceral mass; opens to outside for gas exchange, excretion, elimination of digestive wastes, and release of reproductive cells
Radula of phylum Mollusca
File-like set of hooked teeth
Mollusks have an open ___ ___
circulatory system
___ and ___ have a closed circulatory system in which blood flows through a complete circuit of blood vessels
squids and octopods
Most marine mollusks pass through a ___ larva stage
trochopore larva stage
In many ___ and ___, the trochopore larva develops into a ___ larva, unique to the mollusks
In many gastropods and bivalves, the trochopore larva develops into a veliger larva, unique to the mollusks
Annelids are in phylum
Annelida
Annelids include
polychaetes, earthworms, leeches
characteristics of Annelids
- Segmented worms with bilateral symmetry
- Tubular body
- Segments are seperated by internal septa
Annelid NS
NS consists of a ventral nerve cord and a pair of ganglia (simple brain)
Annelids have a ___ circulatory system
Closed
Annelids have a ___ digestive tract
complete
annelid respiration
is cutaneous
each segment of an annelid has
a pair of metanephridia
Rotifers are a part of phylum
Rotifera
Characteristics of Rotifers
Crown cilia on their anterior end that beat rapidly during swimming and feeding
Rotifers have a ___ digestive tract
complete
Rotifers NS
“brain” and sens organs, eyespots
Rotifers have ___ with ___ cells remove excess water
Rotifers have Protonephridia with flame cells
Rotifers have no true ___
coelom but may have evolved from animals with a true coelom
Ecdysozoa includes
nematodes and arthropods
Ecdysozoa are characterized by
a noncellular body covering secreted by the epidermis (cuticle), which undergoes ecdysis
ecdysis
molting
process by which an animal sheds its outer covering which is then replaced by growth of a new one
Nematodes are a part of phylum
nematoda
Nematodes characteristics
roundworms have a cylindrical, threadlike body, pointed at both ends, covered with a protective cuticle that is shed periodically
Nematodes have a ___ filled pseudocoelom which acts as a ___ ___
nematodes have a fluid-filled pseudocoelom which acts as a hydrostatic skeleton
Nematodes symmetry
Bilateral symmetry
nematodes have a ___ digestive tract
complete digestive tract
Nematodes have no specific ___ sttructures
nematodes have no specific circulatory structures
Nematodes include
decomposers, predators of smaller organisms, and parasites
parasitic nematodes
- Hookworms
- Pinworms
- trichina
Hookworms
attach to the lining of the intestine and suck blood, causing tissue damage and blood loss
Pinworms
commonly found in children
tiny pinworm eggs are ingested by eating with contaminated hands
Trichina
worm lives inside a variety of animals
humans become infected by eating undercooked, infected meat
Arthropods are a part of phylum
Arthropoda
___ are the most biologically successful group of animals
arthropods
Arthropods have a ___ circulatory system
open circulatory system
hemolymph flows into large spaces that make up the hemocoel; return to the heart through ostia in its walls
Digestive system of Arthropods
similar to that of earthworms
Arthropods have a small coelom which
contains organs of the reproductive system
Important arthropod adaptations
- Segmentation
- Hard exoskeleton
- Paired, jointed appendages
- A variety of effective sense organs, including antennae and compound eyes composed of many light-sensitive ommatidia
Arthropods exoskeleton
makes specialized respiratory systems for gas exchange
Most aquatic arthropods have
gills
some terrestrial forms have ___ or ___ tubes; other, ___ book lungs
some terrestrial forms have tracheae or tracheal tubes; other, platelike book lungs
shedding the exoskeleton =
a net metabolic loss
molting make arthropod temporarily vulnerable to predators
Crayfish Respiratory
layers of featherlike gills
Spiders Respiratory
book lungs (folds incirease surface area)
Insects respiratory
spiracles (holes in abdomen) and tracheal tubes for breathing
Ecdysis
process of molting old exoskeleton
four steps of Ecdysis
- Preecdysis
- molting gel
- New exoskeleton
- expansion
Preecdysis
animal hides and is inactive
apolysis: hormones breakdown old procuticle
Molting gel
space between old exoskeleton and hypodermis fills with fluid
new exoskeleton
hypodermis begins to secrete
expansion (Ecdysis)
animal takes in air and water splitting old exoskeleton and arthropod wriggles out
Arthropods evolved rapidly during which period?
cambrian radiation
Insecta are a part of Subphylum
Hexapoda
Insects are
articulated, tracheated hexapods
insect body consists of three parts
head, thorax and abdomen
insects have uniramous appendages
Three pairs of legs that extend from the thorax- many have one or two pairs of wings
Bodily characteristics of insects
- One pair of antennae
- simple and compound eyes
- complex mouthparts adapted for piercing, chewing, sucking or lapping
tracheal system of insecta
air enters tracheal tubes through spiracles in the body wall
excretion: class insecta
malpighian tubules receive metabolic wastes from the blood and discharge them into the intestine
The most successful group of animals in terms of number of individuals, number of species, diversity and geographic distribution
insects
Certain insecta species exist as
societies
