-
Animals are _______ and are _____________.
Heterotrophs, multicellular
-
How many animals are invertebrates?
99 percent
-
In the animal kingdom, most are __________.
Marine
-
What are the simplest animals?
Sponges
-
What do sponges attach to?
hard substrates
-
What do the bodies of most sponges lack? What are the cells not organized into?
- Symmetry
- Tissues or organs
-
How is water drawn through the porocytes?
By the whipping action of the flagella
-
Where are the flagella found?
On special cells called chaonocytes lining the atrium
-
How does a sponge digest food?
Food particles sucked into the atrium are trapped in the collars and later ingested by the chaonocytes
-
What does the phylum Cnidaria include?
jellyfish, hydra, sea anenomes and corals
-
What symmetry do cnidarians and ctenophores have?
radial symmetry
-
What are the stinging cells called on the tentacles?
cnidocytes
-
Each cnidocyte has a small barbed harpoon called?
A nematocyst to spear prey
-
What are the two basic body forms of Cnidarians?
- Medusae: free-floating, gelatinous, often umbrella shaped, lots of mesoglea and tentacles and mouth face downward
- Polyps: cylindrical, pipe-shaped, attached, little mesoglea, and mouth and tentacles facing upward
-
What have most bilaterally symmetric animals evolved?
A definite head end (cephalization)
-
What are the simplest animals that have organs?
Flatworms
-
Flatworms don't have a ____________ so __________ and ___________ must pass through the solid body by __________.
circulatory system, oxygen, carbon dioxide, diffusion
-
What is the gut of a flat worm like? Benefit?
Highly branched, giving each cell access to food molecules
-
In flatworms, what is the only opening to the gut? What enters and exits it?
Mouth; food and waste
-
Other then flatworms, what do all other animals have?
An internal body cavity called a pseudocoelom
-
What were the improvements of the pseudocoelom?
- circulation: fludis within the body cavity can function as circulatroy system
- movement: fluid in body cavity makes animal's body rigid enabling muscle driven body movement
- organ function: body organs surrounded by body cavity can function without being distorted by surrounding muscles
-
What were nematodes/roundworms the first organsims to develop?
An internal body cavity
-
Where do most nematodes live?
in the soil
-
What three distinct regions is the body of a mollusk made up of?
- visceral mass: central sections containing body organs
- mantle: wrapped around visceral mass
- gills: filamentous projections, rich in blood vessels, capture oxygen from water and release carbon dioxide
-
What are the three classes of mollusks?
- Gastropods (snails and slugs): use muscular foot to crawl, mantle often secretes a hard protective shell
- Bivalves (clams, oysters, and scallops): secrete two-part shell (valve) with hinge; filter feeders
- Cephalopods (octopuses and squids): modified cavity that creates jet propulsion system to propel rapidly through water
-
What is a radula?
a rasping tongue-like organ
-
What mollusks don't have radula?
Bivalves
-
What is the advantage of segmentation?
Flexibility offered with segments having different functions
-
What three characteristics do all annelids share?
- repeated segments
- specialized segments
- connections between segments
-
What does each segment of an annelid have?
Digestive, excretory and locomotor organs
-
Fluids within coelom creates what?
A hydrostatic skeleton for rigidity
-
What were the first animals with jointed appendages?
Arthropods
-
What are the segments of adult arthropods?
-
What kind of skeleton do arthropods have?
Exoskeleton made of chitin
-
What is the arthropod skeleton limitation?
Can't support great amount of weight
-
What were the first animals to develop an endoskeleton?
Echinoderms
-
What do echinoderms include?
- sea stars (starfish)
- sea urchins
- sand dollars
- brittle stars
- sea cucumbers
-
What kind of symmetry are echinoderms characterized by?
pentamorous radial symmetry
-
What special structures do echinoderms have?
Tube feet with suction pads situated at extremeties used for locomotion
-
What are tube feet controlled by?
hydraulically by water vascular system
-
What three things do all chordates have at some point in their lives?
- nerve cord: single, hollow dorsal nerve cord
- notochord: long, stiff rod that forms beneath nerve cord; between nerve chord and developing gut in early embryo
- pharyngeal slits: series of slits in wall of pharynx (located behind mouth, muscular tube connecting mouth to digestive tract and windpipe
|
|