Invertebrates - Ch. 28 Flashcards
invertebrates
- animals without a backbone
- come in many different shapes and sizes
- can be compared by looking at body plan, cephalization, and the way food is digested
porifera
- asymetrical
- ability to regenerate
- do not produce true tissues
- no cephalization - has signaling proteins
- have collar cells similar to choanocytes and is how the sponge filter water
how do sponges eat?
- water enters the sponge through its pores which then pump water into the sponge
- collar cells inside the sponge filter food and microorganisms from the water
- water flows into the central cavity and out the top of the sponge through the osculum
what are some examples of porifera?
sponges
cnidaria
- radial
- can be medusa or polyp form
- no cephalization
- have cnidocytes that release barbs of poison (sea slugs do not)
- no segmentation
- have complex tissues, a gut, nervous system
- nervous system is of net fibers
- only has one opening for food and waste
- diploblastic
what are some examples of cnidaria?
hydras, jellyfish, anemones
ctenophora
-hermaphroditic
-radial
have comb rows of cilia for movement
-lack stinging cells
-diploblastic
what are some examples of ctenophora?
comb jellies
what are some characteristics of acoelomates?
- bilateral
- diploblastic
- cephalization
- has a brain and nervous system
- incomplete digestive system - 1 opening
flatworms
- acoelomates
- gas exchange through diffusion across skin
- no circulatory system
- flame cells remove excess water
Platyhelminthes
- triploblastic
- protostome
- acoelomates
- can be free living or parasitic
- bilaterial
- cephalization
- 2 sensory lobes
what are some characteristics of pseudocoelomates?
- triploblastic
- bilateral
- cephalization with a brain and nervous system
- complete digestive system
- no circulation
annelida
- segmented
- triploblastic
- protostomes
- coelomates
- full digestive system
- bilateral
what are some examples of annelida?
- earthworms
- leeches
earthworms
- class oligochaeta
- some segments are specialized for eating and reproduction
- break down waste and excrete waste called castings
- burrow in soil allowing water and air to reach deep into the soil
- stiff bristles on the outside of their body helping them to move
leeches
- some are parasites and suck others animals’ blood and others eat dead animals
- leeches secrete a chemical that keeps blood from clotting
mollusca
- has a large foot for movement
- bilateral
- triploblastic
- protostome
- have a viceral mass
- have a mantle
- have a shell
- mostly open circulatory system with the exception of cephalopods
- complex ganglia for nervous system
what are some examples of mollusks?
- gastropoda (slugs and snails)
- pelecypoda (oysters and clams)
- cephalopoda (octopus and squid)
how do mollusks eat?
- gastropods: scavengers
- clams and bivalves: filter feeders
- cephalopods: predators
what do complex ganglia in mollusks do?
- control breathing
- move the foot
- control digestion
arthropoda
- jointed limbs
- segmented body
- have a head, thorax, and abdomen
- exoskeleton made of chitin or proteins
- triploblastic
- bilateral
- protostomes
- coelomates
what are some examples of anthropoda?
- crustacea
- arachnida
- chilipoda
- diplopoda
- insecta
anthropoda nervous system
- cephalization - well developed brain
- most can detect light but not form an image
- some can see images because of compound eyes
insecta
- triploblastic
- protostome
- segmented
- pair of antennae
- 3 pairs of legs for walking, some use for jumping also
- coelomates
- 2 pairs of wings
- bilateral
how do insects develop?
through metamorphosis - from an egg to an adult
echinodermata
- spiny skinned
- live on the sea floor
- endoskeleton
- radial
- coelomates
- triploblastic
- deuterostomes
what are some examples of echinodermata?
- star fish
- sea urchins
- sea cucumbers
- brittle stars
- sand dollars
ganglia
a structure containing a number of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber
open circulatory system
pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells. blood is pumped by the heart into the body cavities, where tissues are surrounded by the blood
closed circulatory system
have the blood closed at all times within vessels of different size and wall thickness. In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities
