Chordates, echinoderms, arthropods, annelids, mollusks, and platyhelminths
Which phyla are radial?
Which phyla are asymmetrical?
Which phyla have coelomate?
Chordates, echinoderms, arthropods, annelids, and mollusks
Which phyla are deuterostomes?
Chordates and echinoderms
Which phyla are protosomes?
Arthropods, annelids, and mollusks
What is spongocoel?
The central cavity of sponges
Facilitates water circulation (not a digestive chamber because no digestive enzymes are released into cavity)
What is the osculum?
The excurrent opening of sponges.
Where water leaves the songe
What are spicules?
a primitive form of the structural support of sponges
What are cnidoblasts?
Stinging cells that all cnidarians have
Used for protection and for catching food
What are nematocysts?
Stinging devices on the surface of the tentacles that cnidarians discharge when they brush against a potential prey item or predator
What is the sexual stage of the cnidarian life cycle?
They contain gonads which are clusters of gametes (eggs and sperm)
What does it mean that hydra are unusual?
They can reproduce both asexually (like polyps by "budding") and sexually (with eggs and sperm, like the medusa form)
Platyhelminths are the first phylum to have what?
Bilateral symmetry, three distinct body layers and true organ systems: sensory, nervous, excretory, and reproductive systems
What is cephalization and which animal displays it?
The differentiation and specialization of the anterior end of the body (in the head)
What advantage are being both bilateral and having cephalization to an animal moving through its environment?
Bilateral symmetry allows the animal to have directed movement which can help when searching for food or escaping predators. It also allows for quicker and precise response to stimulation since the nervous system is cephalized and much more complex.
How do planarians take in food and pass wastes?
Through a pharynx, an extendible, muscular tube on the ventral side of the animal
How does the gastrovascular cavity differ from a spongocoel in structure and function?
The gastrovascular cavity is for digestion and internal transport, the spongocoel facilitates water circulation.
The spongocoel is bigger than the gastrovascular cavity.
Which phylum are hermaphrodites?
What three structures do all mollusks have in common?
A muscular head-foot which is a visceral mass
A fleshy mantle that secretes
A protective (internal or external) shell
What are the three major classes of mollusks?
Surface-feeding gastropods (snails)
Filter-feeding bivalves (clams)
Free-swimming, predatory cephalopods (squids)
What is the mantle?
A dorsal fold of tissue that secretes the shell
In clams and snails, the shell is external; in squid and octopus, the shell is reduced and internalized
Contains the gills
Water drawn into the mantle cavity is used for gas exchange
In squid, water forced out of the mantle cavity can be used for jet propulsion
Two large muscles attached to the shell and used to pull the valves tightly closed in clams
How hass the head-foot evolved in cephalopods
It has evolved into a separate head and several, sucker-covered tentacles
What are siphons?
Clams extensions of the edge of the mantle
Water passes into the mantle cavity through the ventral, incurrent siphon and out through the dorsal, excurrent siphon
What does it mean to be serially segmented?
The body is composed of repeated similar segments or "metameres"
This condition is known as metamerism and is also found in arthropods and chordates
What is coelom?
A "second" body cavity that surrounds and is completely separate from the digestive cavity
Inside this fluid-filled space the internal organs:
a. increase their surface are by bending and coiling (human intestine)
b. can fill, empty, and slide past one another, lubricated with coelomic fluid (human lungs)
What are setae?
Setae are bristles on earthworms that attach to surfaces and prevent backsliding during persisteltic motion
What is parapodia?
Pairs of fleshy projections along the side of the clamworms body
How might parapodia aid in gas exchange?
Parapodia have a large surface area and keep fresh water with a high oxygen concentration constantly moving over the respiratory surface.
How might the parapodia aid in locomotion?
The contraction of the parapodia allow it to move
What is the largest phylum?
What does arthropod mean?
What two unique features do all arthropods have in common?
An exoskeleton and jointed appendages
What three parts are insects divided into?
head, thorax, and abdomen
In crustaceans and arachnids, the head and thorax are fused into a cephalothorax
Which body divisions of arthropods still show the remnants of ancestral segmentation?
How many pairs of walking legs to arthropods have and to what body division are they attached?
Insects have 3
Crustaceans and arachnids have 4
The thorax or cephalothorax
Which arthropods have antennae?
Insects and crustaceans
How many pairs of antennae do insects have? crustaceans?
Insects have one and crustaceans have two
What are chelicerae?
In arachnids, the first pair of appendages that has been modified into fang-like mouth parts
What are pedipalps?
In spiders, the second pair of ancestral appendages
For manipulating food and, in males, for transferring sperm to the female
Which arthropod has wings?
What do wings enable insects to do?
Exploit widely dispersed food sources
Escape from predators
Disperse into new habitats
Larger, with multiple facets/lenses
Compound eyes form images and are especially well adapted for detecting motion
Water vascular system
Unique to Echinoderms
The tube feet of the starfish are part of this
hydraulic, water fills the tube feet making them rigid enougth to all the starfish to walk
Protrusions of the coelom that serve as sites of gas exchange on starfish
All chordates have:
A dorsal, hollow nerve cord
A notochord (a stiff rod running under the nerve cord)
Pharyngeal ("throat") gill slits
The seven classes of the subphylum, vertebrates (animals with backbones) fall into two major groups:
The fishes (lamprey eels, cartilaginous fishes (sharks) and bony fishes
The tetrapods (four foot) amphibians, reptiles, birds, and mammals