EXAM
Cephalization - ANSWERS-Having a well recognized anterior head
with a brain and sensory receptors
Deuterostome - ANSWERS--radial cleavage occurs
-anus appears first
-body cavity (coelom) Arises as a pro or mesodermal pouches which
enlarge until they meet and fuse
(humans are deuterostomes)
Protostome - ANSWERS--spiral cleavage occurs
-mouth appears first
-splitting produces the body cavity (Coelom)
-earthworms
Anatomy and life cycle of sponges - ANSWERS--cellular level of
organization
-sac-like body with many pores
-multicellular but no tissue
-filter feeders
-choanocytes, flagellated cells
-asymmetrical
,Anatomy and life cycle of cnidarians - ANSWERS--radial symmetry
-have true tissues
-aquatic
Way of life of sponge vs. cnidarian - ANSWERS--sponges are filter
feeders, can reproduce sexually or asexually
-cnidarians can move using cilia, capture prey by stinging, hydras
reproduce asexually but other types of cnidarians can reproduce
sexually
Describe the way of life of flatworms, planarians and tapeworms -
ANSWERS--flatworms: incomplete digestive tract, only one opening
(the mouth). When 2 openings are present the digestive tract is
complete.
-planarians: free living, have muscles and excretory, reproductive and
and digestive systems. Wrap around the prey
-tapeworms: parasites, come into the body through uncooked meat
and attaches to the intestinal wall
3 basic characteristics of molluscs - ANSWERS--visceral mass,
contains the internal organs
-foot, for locomotion
-mantle, envelops the visceral mass
, Compare and contrast Gastropoda, cephalopods, and bivalves -
ANSWERS-Gastropoda- "stomach footed", animal moves by muscle
contractions that pass along the foot. Many are herbivores (snails)
Cephalopods- foot has evolved into a funnel or siphon around the
head. Also have a powerful beak (octopus)
Bivalves- shells have 2 parts, filter feeders (clams)
Basic characteristics of Annelids (earthworms) - ANSWERS--
segmented (rings on the outside of body)
-hydrostatic skeleton, fluid filled interior
-locomotion occurs by contraction and expansion of each body
segment
Three basic characteristics of arthopods - ANSWERS--segmentation
-jointed appendages
-an exoskeleton
Compare and contrast crustaceans, insects, and arachnids -
ANSWERS--Crustaceans: hard shell, head usually bears a pair of
compound eyes and 5 pairs of appendages (2 are antennae, 3 are used
in feeding)
-Insects: body is divided into a head, thorax and abdomen. Have the
most species
-Arachnids: cephalothorax has 6 appendages, internal organs