Chapter 35 Flashcards
Name some characteristics of mollusks.
They exhibit bilateral symmetry. They undergo a trochophore state. They use radula to acquire food.
Mollusk bodies are divide into what two main regions?
visceral mass and head-foot
Which region contains the mouth and sensory structures in a mollusk?`
head
Which region contains the heart, digestive, reproductive, and excretory organs of a mollusk?
mantle
Which mollusk structure produces the hard valves or shells?
mantle
paired clusters of nerve cells controlling the locomotion, feeding, and sensory processing are located where?
in the head-foot and visceral mass
A radula can be used to
feed
The process that occurs in gastropods to produce a head that can be retracted is called
torsion
the largest and most diverse class of mollusks
gastropods
Give some examples of gastropods.
snails, conchs, and abalones
The structure of a land snail that acts as a modified lung is the ___.
mantle activity
The marine gastropod that has no shell is the ___.
nudibranch
Most bivalves are ___.
sessile
The mantel cavity of a clam is sealed except for two fleshy tubes called ___.
siphons
Clams reproduce ___.
sexually only
Most cephalopods are ___.
free swimming
Name three facts about cephalopods and their nervous system.
They have the largest brain of any invertebrate. They are capable of learning. Their tentacles have numerous sensory neurons.
Specialized pigment cells that allow a cephalopod to blend with its environment are called ___.
chromatophores
A squid usually has ___ tentacle(s) used for preying on and capturing food.
2
Architeuthis is the largest invertebrate. What is it?
giant squid
What are some characterists of the chambered nautilus?
It is the only cephalopod with an external shell. It has fluid-filled chambers that help with buoyancy as it discharges water. It uses only the outermost chamber of its shell for occupancy.
The segmented coelom of the earthworm allows for ___.
muscle contraction producing locomotion independent from organ function
the common characteristic that suggests mollusks and annelids are related is ___.
trochophore stage of development
The most commonly known oligochaete is the ___.
earthworm
contraction of which muscle in the earthworm causes the initial increase in pressure of the coelomic fluid initiating locomotion?
circular
Name two circulatory structures in the earthworm that are responsible for pumping blood.
dorsal blood vessel; aortic arches
An annelid is equipped with excretory tubules to eliminate excess water. These tubules are called what?
nephridia
The clitellum is responsible for ___.
secreting mucous that aids in the reproductive process of the annelid
The largest class of annelids is ___.
polychaeta
The class of Hirudinea includes ___.
leeches
Name some characteristcs of leeches.
They secrete an anesthetic so the host does not feel the leech. They can ingest ten times their own body wieght in blood. They secrete an anticoagulent to keep the blood from clotting.
The majority of polychaetes ___.
are covered with numerous setae and parapodia
