48 terms

Porifera, Cnidaria & Worms

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sessile
This describes an organism that remains attached to a surface for its entire life - it does not move
collar cells / choanocytes
Specialized cells with flagellum that create a current to bring water and food into the body of a sponge for filter feeding
osculum
A large opening on a sponge through which filtered water is expelled
hermaphroditic
An organism that has both the male and the female reproductive organs
invertebrate
An animal that lacks a backbone
nematocysts
Small harpoon-like structures that when triggered can inject a toxin / venom into prey or predators. Found in Cnidarians for feeding or defense. These are the stinging cells
planula
The free-swimming, ciliated larva of a Cnidarian - allows for movement to new areas.
spicule
Glass-like structures found in the sponge that give support and structure. They act like a primitive skeleton
amoebocyte
A cell that can move around the body of the sponge to make the spicules and transport nutrients and wastes. Also, secretes chemicals to make the sponge taste bad.
heterotrophic
An organism that must consume food - eat
acoelom
Animals that do not have a body cavity. The three tissue layers (ectoderm, mesoderm and endoderm) are all packed together with no space.
coelom
Animals that do have a true body cavity. There is a space between the mesoderm and ectoderm
peritoneum
A multi-layered membrane that protects and holds the organs in place
pseudocoelom
Animals that have a false body cavity. There is a fluid filled area between the mesoderm and ectoderm
endoderm
An inner tissue layer
mesoderm
A middle tissue layer
ectoderm
An outer tissue layer
mesoglea
A jelly-like layer found in Cnidarians but it is NOT a true tissue layer
cephalization
A concentration of nerve tissue at the anterior end of the animal - start of the brain
symmetry
Refers to how the body plan of an animal is organized and arranged
bilateral symmetry
A body plan in which a single, imaginary line can divide the body into two equal halves - the left side and the right side; characteristic of Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, and Chordata
radial symmetry
A body plan in which the body parts repeat around a central point or axis of the body; characteristic of Cnidarians and Echinoderms
asymmetry
A body plan in which the animal lacks symmetry and has an irregular shape; characteristic of Porifera (sponges)
gastrovascular cavity
An area in animals that acts as a separate area for digestion. Like a primitive stomach. Food is digested here.
parasitic
An organism that feeds off of another living organism
tegument / cuticle
The outer tissue layer of a tapeworm that prevents it from being digested by its host
segmented
Having a body that is separated into parts such as we see in Annelida
scolex
The head of a tapeworm, which has hooks and suckers to adhere to the host tissues
proglottid
The detachable sections of a tapeworm that has male and female reproductive organs; breaks off when its eggs are fertilized and passes out of the host's intestine. The tapeworm can fold over on itself and self fertilize by mating between two proglottids
setae
Bristles on the ventral / underside of the tapeworm that are used for traction
peristalsis
The rhythmic muscle contraction
ganglion
A collection of nerve cells
clitellum
Area of earthworm where mating occurs and it secretes a cocoon around the fertilized eggs
gizzard
A grinding organ found in the earthworm
crop
A storage area for food waiting to enter the gizzard of an earthworm
nephridia
Excretory organs that act like kidneys removing the waste from blood
esophagus
The passage between the pharynx and the crop in the earthworm - moves food along
pharynx
Muscular part that pushes food to the esophagus of the earthworm and allows it to get some oxygen
cyst
A dormant stage of a worm which has the baby worm encased in a thick protective coat awaiting to reach its proper host. Can be found in the muscle tissue of an intermediate host
dorsal
The back of the animal
ventral
The belly or underside of the animal
posterior
The tail end of the animal
anterior
The head end of the animal
vertebrate
An animal with a backbone
carnivore
A consumer that obtains energy by eating only animals.
herbivore
A consumer that obtains energy by eating only plants.
omnivore
A consumer that obtains energy by eating both plants and animals.
notochord
A tough, flexible, cartilaginous rod that runs along the back of chordates providing support. It protects the nerve cord.