Chapter 7: Survey of Animals II Protostomes

What kind of symmetry do triploblastic animals display?

Bilateral

What is bilateral symmetry associated with?

Cephalization

Cephalization

Process in which the nervous system becomes concentrated at the anterior end of the organism; eventually produces a head region concentrated with sensory organs

Morula

Solid mass of cells

What does gastrulation do?

Creates a pocket/opening (blastopore) which develops into a mouth or anus

What is an anus first organism called?

Deuterostome

What is a mouth first organism called?

Protostome

What are the 3 layers of the gastrula?

Endo, ecto, and mesoderm

What kind of body cavity is Ascaris?

Pseudocoelomate

Pseudocoelomate

Body cavity is not completely lined with mesodermal cells

What is the most common worm infection in humans?

Ascariasis

What causes Acariasis?

Ingesting ascaris eggs

Where are ascaris eggs present?

Contaminated dirt, vegetable or fruit that has not been thoroughly washed or cooked

Where do ascaris larvae and adult worms live?

Small intestine and cause intestinal disease

What kind of coelem does planaria have?

Acoelomate

Acoelomate

No coelem

What kind of nervous system does planaria have?

Simple brain in head region

How do planaria move?

Contractions of muscles and beating of cilia (on ventral surface)

How do planaria reproduce?

Hermaphroditic, no self fertilization, sexual reproduction- simultaneously fertilizing each other or asexually by tearing itself into 2 halves w/each half regenerating the other to produce 2 organisms

Auricles

Ear like projections w/concentrated chemoreceptors that function like a nose

Digestive and nervous systems in parasitic planaria

Minimally developed

If parasitic planaria do not have a respiratory or circulatory system, how are these needs met?

Diffusion because of flattened body

What kind of reproductive system do parasitic planaria have?

Well/highly developed reproductive

What is the oral sucker in a planaria?

Mouth

What does the ventral sucker in the parasitic planaria do?

Helps the animal hang onto its host

What kind of worm is Taenia?

Tapeworm

What kind of coelem does Taenia have?

Acoelomate

Where do Taenia live?

Intestine of animals (ex. cow, pigs, humans)

Taeniasis

Tapeworm infection caused by eating raw or undercooked infected beef or pork

What is the digestive system in Earthworm?

Long tube

Crop

Temporary storage of food

Gizzard

Grinding of food

Intestine

Digestion and absorption

What is the infold in the intestine of an Earthworm?

Typhlosole

What does the typhlosole do?

Increases surface area to maximize nutrient absorption

Where is the booty located in an Earthworm?

Last segment

Pygidium

anus/last segment in an Earthworm

What kind of coelom is an Earthworm?

Coelomate

Coelem

Body layer surrounded by mesodermal layers

How do Earthworms move?

Burrowing by alternating contractions of longitudinal and circular muscles in body wall

What does Earthworm nervous system consist of?

Brain and ventral nerve cord with ganglia and nerve endings in each segment

Setae

On ventro lateral sides of most segments along its body help anchor the earthworm to surrounding surface

Why is it important that earthworm feeds on decaying vegetation?

It helps speed up process of decomposition and provide soil w/its own waste products as fertilizers

What are the types of mollusks?

Gastropods, chitons, bivalves, cephalopods

What are the 3 major structural components of mollusks?

Foot, mantle, visceral mass

What is different about mollusk coelem?

Restricted to an area surrounding the heart

Foot

Highly muscular, used for locomotion

Mantle

Body wall covering visceral mass, secretes external shell protecting organism

What does Mantle do?

Secretes external shell protecting organism

Mantle cavity

Mantle extending beyond main body

What does the mantle cavity house?

Gills

What are the gills important for?

Gas exchange

Visceral mass

Internal organ systems excretory, circulatory, digestive

How do gastropods move?

Large flat foot for locomotion

Example of a gastropod with no shell

Slugs

Example of a gastropod with one part spiral shaped shell

Snail

Chiton shell

Consists of 8 calcareous plates

What kind of movement do chitons have?

Sessile lifestyle adopted by attachment to rocks via broad foot

How do chitons feed?

Using radula to scrape algae from rocks

How do chitons breathe?

Through gills on both sides of foot

What kind of foot do bivalves have?

Wedge shaped

Bivalve shell

2 part hinged

What do edges of bivalve mantle form?

Dorsal excurrent siphon and ventral incurrent siphon

Where does water enter in bivalve?

Through incurrent siphon

Where does water leave through in bivalves?

Excurrent siphon

Why is important for bivalve to keep water flowing through its path?

Beating of cilia

What are types of bivalves?

Mussels,scallops, oyesters

Cephalopods feeding

Carnivores

What does the strong beak in cephalopods do?

Crushes its prey

What kind of nervous system does cephalopods do?

Well developed

How does the cephalopod move rapidly?

By jet propulsion

What is the importance of a closed circulatory system?

Supports high metabolic activity

What does the epidermis in cephalopods contain?

Chromatophores

Chromatophores

Change body color for camouflage and courtship

Inc sac

Filled with melanin pigments released to temporarily disable their predator’s sense of sight and smell while they escape

What are the types of arthropods?

Crustaceans, hexapods, chelicerates, myriapods

What are the 3 regions of crustaceans?

Head, thorax, abdomen

What does the head contain in crustaceans?

2 pairs of sensory antennae, number of paired mouthparts for feeding, and pair of compound eyes

Chelipeds (pincers)

Prey capture, defense, holding female during mating

What is the importance of thorax legs?

Leg movement helps circulate water over gills

What does the thorax contain?

Chelipeds, 4 pairs of walking legs

What is the significance of swimmenets

Movement helps bring water to gills

Female swimmets

Soft and alike, used to carry fertilized eggs and newly hatched larvae

Male swimmets

First pair larger and harder; specialized to help transfer sperms into female’s oviducts during mating

What does the last abdominal segment have in arthropod abdomen?

Telson and uropod

Telson

Terminal extension of the body

Uropods

Broad and fan shaped on each side of telson

What do the telson and uropods do?

Form a tail fan which is important for the animal’s backward swimming

Example of hexapods

Insects

What are the 3 body regions of insects?

Head, thorax, and abdomen

Head (hexapod)

Mouthparts, compound eyes, one pair of antenna

Grasshopper legs

First 2 pairs of legs are for walking, last pair for jumping

How does air enter the body in insects?

Through spiracles

Spiracles

Small openings of exoskeleton

What do tracheoles do in insects?

Form a network that delivers oxygen to various metabolically active tissues throughout the animal’s body

What do longitudinal trunks do?

Along the length of the animal to facilitate air diffusion to different body regions

Example of chelicerate

Spider

What are the body regions in chelicerates?

Cephalothorax and abdomen

Cephalothorax

Bears jointed appendages