Exam 3 Flashcards
What are the potential functions of a coelom?
space for organ development
increased surface area
storage
elimination of waste
What is contained in the coelom?
heart, nephridia and gonads
How are molluscs important to humans?
Food
Pearls
Shells
What are some general characteristics of molluscs?
triploblastic coelomate bilaterally symmetric redula open circulatory system 3 body regions
What are the three major regions of the molluscan body plan?
What does each generally contain?
Head-Foot : radula and mouth
Visceral Mass : organ systems
Mantle : Provides protection, secretes the shell
How are pearls formed?
When a piece of debris enters the shell, tissue type layers are secreted around it, resulting in a pearl
What are general characteristics of Gastropods
Molluscs
Some shelled
Marine, freshwater, terrestrial
What is torsion? Advantages? Disadvantages?
The visceral mass, mantle, and mantle cavity all twist 180 degrees
head retraction, sensory organs around head
contamination with wastes
How do Gastropods feed?
What is a radula?
Proboscis
radula, used for scraping
What are the pneumostome and spermatophore of the gastropods?
pneumostome: opens to the outside and moves waste
spermatophore: bundles of sperm
What are some general characteristics of Bivalves?
Molluscs
Two valves
sedentary
no defined head region
What are some characteristics of the Bivalve shell?
Umbo : where the shell begins growing
teeth
attached dorsally to a hinge ligament (one piece)
abductor muscles (keeps the shell closed)
How do Bivalves feed?
How is this different from Gastropods?
Filter feeders : remove algae and bacteria from the water
no head
no radula
What type of circulatory system do bivalves have?
open circulatory system
How do bivalves reproduce?
What is a glochidium?
Most dioecious, external, fertilization both internal and external
Glochidium : small larvae stage that attaches to fish and develops
What are some general characteristics of Cephalopods?
Molluscs
Foot modified into tenticles or funnel
Most lack an external shell
What type of shell do cephalopods have?
Most have an internal shell or no shell
Nautilus are the only ones to have an external shell
How do cephalopods feed?
How is this different from the other classes of molluscs?
Predatory, posses arms, tentacles, and/or suction cups
Jaws and radula
How do gastropods move?
free swimmers
crawl
walk
What is different about the cephalopod circulatory system compared to the other classes of molluscs?
Cephalopods are the only molluscs with a closed circulatory system
What is unique about cephalopods eyesight?
Complex eye
highly developed eyesight
What are chromatophores and ink glands?
Chromatophores: pigment cell that allows for color changes
Ink glands: defense mechanism
How do cephalopods reproduce?
Dioecious, spermatophores, eggs form a gelantinous mass, direct development
What are some general characteristics of Annelids?
Triploblastic, coelomate, bilaterally symmetric, closed circulatory system, segemented worms
How are annelids important to humans?
Food
Medicine
Fish Bait
Soil mixture
What is metamerism?
Why is it beneficial?
Metamerism: Segmented arrangement of body parts
Benfits: Hydrostatic compartments, lessens impact of injury, increased complexity, increased movement efficiency.
What is a cuticle?
Outer layer
Provided protection
What are some general characteristics of Polychaetes?
Annelids
Chaetae
Most marine
What are parapodia?
What are they used for?
Parapodia : unjointed appendages used for movement, increased surface area, and sensory
How do Polychaetes move?
Longitudinal muscles
Parapodia
Burrowing species
How do Polychaetes feed?
Scavengers, herbivores, predators, filter feeders
direct deposit vs selective deposit
How do most Polychaetes exchange gas?
Diffusion
What type of circulatory system do Polychaetes possess?
Closed circulatory system
What is epitoky?
the development of posterior sexual parts to be released into the environment
What are some general characteristics of Oligochaetes?
Annelids
No parapodia
Few chaetae
Clitellum for reproduction
How do Oligochaetes move?
Alternately contract muscles
Chaetae used to anchor
effective burrowers
How do Oligochaetes feed?
Scavengers
Have a crop and gizzard
What type of circulatory system do Oligochaetes have?
closed circulatory system
How do Oligochaetes reproduce?
regeneration, moneocious
What ecological role do Oligochaetes play?
Soil mixing
aeration and water percolation
accelerate decomposition
What are some general characteristics of Hirudinea?
No parapodia
No chaetae
Posses a clitellum
Posterior and Anterior suckers
How do Hirudinea move?
Suckers used as anchors, muscles alternately contract
How do Hirudinea feed?
Feed off of body fluids or small invertebrates
3 blade like jaws
muscular pharynx
crop
What is Hirudo medicinalis?
“bleeding”
reduces hermatomas and blood clots
Anesthesia
Anti-cogulant
Do they produce a clitellum?
Only in the spring
What are some general characteristics of Nematodes?
Triploblastic, bilaterally symmetric, complete digestive tract
PSEUDOcoelomate
What is ecdysis?
Molting of the cuticle
How do nematodes feed?
Mouth with teeth
Jaws or stylets
Muscular pharynx
Complete digestive tract
Ascaris lumbricoides
Giant Intestinal Roundworm
one host
develop in the lungs and then progress to the small intestine
Necator americanus
New World Hookworm
One host
Lives in the small intestine
Trichinella spirali
Porkworm
Lives in the intestines of humans and carnivores
lays cysts of eggs
Can cause Trichinosis
Enterobius vermicularis
Human Pinworm
High infection rate in children
Wuchereria spp
Filarial worms
2 hosts, mosquitoes and humans
Can cause Elephantitus in humans and heartworm in dogs
What are some general characteristics of Arthropods?
Monophyletic, triploblastic, coelomate, bilateral symmetry, complete digestive tract
What are characteristics that make Arthropods so successful?
Metamerism: Segmentation Tagmatization: body regions Versatile Exoskeleton Sclerotization: hardening of the exoskeleton Molting/Ecdysis Respitory systems Highly developed sensory organs Complex Behaviors Metamorphosis
What are some general characteristics of the SUBPHYLUM Trilobita?
Extinct, Exclusively marine
What are some characteristics of the SUBPHYLUM Chelicerata?
No discrete head region 2 tagmata No antennae Chelicerae Pedipalps 4 pairs of walking legs
What is a tagmata?
What two tagmata do Chelicerata have?
Prosoma: in the cephalothorax, feeding locomotion and sensory
Opishothoma: in the abdomen, contains internal organs
What are the paired appendages used for in Chelicerata?
Chelicerae: 1st pair of appendages, for feeding
Pedipalps: 2nd pair of appendages, used for feeding, locomotion, and reproduction
4 pairs of walking legs
What are some general characteristics of Merostomata?
Arthropod
Scavengers
Book gills
What are some general characteristics of the Order Araneae?
"True spiders" Pedicel : "cinched" waist sedentary, active hunters, book lungs, malpighian tubules, simple eye sensory setae Spinnerets, complex behaviors Peromones Oviparous - lays eggs
