lecture 6: Animals II

Question 1

basal animals have …

Answer 1

general derived traits

lack more specific derived traits present in most animals

Question 2

porifera

Answer 2

basal metazoa

Question 3

cnidaria

Answer 3

basal emuetozoa

Question 4

Phylum Porifera

Answer 4

• basal metazons

- mutlticelluar, least complex animals that have spores

Question 5

sponge morphology

Answer 5

• simple sponges - some are more complex

- osculum: open end

Question 6

spongooceol: central cavity

Answer 6

• water moves through, food is filtered out

- not a digestive cavity - digestion in intracellular

Question 7

choanocytes

Answer 7

• flagellated collar cells of the microvilli, lines spongocoel
• feeding cells of sponges, ingests bacteria, food particles
• very similar to choanoflagellates

Question 8

phylum cnidaria

Answer 8

• basal eumetazoans
• true tissues
• raidal symmetry
• diploblastic
• thin ( 2 layers) gastrovascular cavity ( circulation etc)
• cnidocytes: specialized stinging cells, unique to cnidaria
• mostly saltwater environments

Question 9

porifera - basal metazoans

Answer 9

• no tissue, no symmetry

Question 10

cnidaria - basal metazoans

Answer 10

• raidal symmetry, diploplasts

Question 11

bilateria ( shared derived traits)

Answer 11

• bilateral symmetry
• triplobasty
• coelom or derivative ( most)

Question 12

protosome

Answer 12

1. diverse, paraphyletic group, ancetral devlopment traits

Question 13

deuterostomes

Answer 13

monophyletic group, derived devlopment traits

Question 14

lophotrochozoa clade

Answer 14

• group based on DNA
• named for derived traits of SOME members
• ancestral traits from bilateria ancestor:
  
  • bilateral symmetry
  • triploblasty
  • protostome devlopment ( some have have deutrostome pattern)

Question 15

phylum platyhelminthes

Answer 15

• dorsoventrally flattened
• acoelomate ( dervided trait)
• free-living or parasitic

Question 16

phylum rotifera

Answer 16

• freshwater/marine, ddamp soil
• very small - 50 um to 2mm - smaller than protists
• corona: crown of cilia at anterior end
• pseudocoelomates

Question 17

phylum Mollusca

Answer 17

• coelomates, 3 main body parts
• mantle: thin sheet of tissue covering visceral mass
• often secretes calcium carbonate shell

Question 18

visceral mass

Answer 18

main body mass, contains viscera (internal organs)

Question 19

foot

Answer 19

structure for locomotion

Question 20

radula

Answer 20

• belt of teeth in mouth area
• scrapes up food
• absent from bivalves

Question 21

major mollusk clades

Answer 21

• gastropods - “stomach-foot”
• bivalves - “two shells”
• cephalopods - “head- foot”

Question 22

phylum annelida

Answer 22

• little rings
• repeated segmentation
• body wall, coelom, many organs divided into segments
• marine, freshwater, soil

Question 23

ecdysozoa clade ( not a phllum, shared dervied traits)

Answer 23

• ecdysis: morlting- shed external coating during growth
• from bilateria ancestor
  
  • bilateral symmetry
  • triploblasty
  • protostome developments ( some deuterstome pattern)

Question 24

phylum nematoda

Answer 24

1. round worms
2. body covered in cuticle
3. pseudocoelomates (derived)
4. aquatic, soil, parasatic
5. heartworm, trichinosis

Question 25

phylum anthropoid

Answer 25

1. joint-foot
2. largest phylum by # species (contains insects)
3. coelomates
4. often have deuterostome development traits

Question 26

anthropod structure

Answer 26

• segmented bodies
• often 3 parts - head, thorax ( legs & wings), abdomen
• derived: joint appendages - often modified - motillity, feeding, sensory

Question 27

derived: exoskeleton

Answer 27

• chitin and protien
• jointed
• covers entire body
• functions: protection, present desiccation, muscle attachment
• costs: limits growth ( must molt to grow