Unit 4 PAL

Question 1

characteristics of animals

Answer 1

• multicellular eukaryotes
• no cell walls
• heterotrophic
• internal digestion
• movement

Question 2

list 5 sources of information for the evolutionary relationships among animal groups

Answer 2

• fossils
• patterns of embryonic development
• morphology and physiology
• protein structure
• gene sequences

Question 3

diploblastic

Answer 3

two tissue layers (ecto and endo)

Question 4

triploblastic

Answer 4

three tissue layers (endo, ecto, meso)

Question 5

protostome

Answer 5

mouth first

Question 6

deuterostome

Answer 6

mouth second

Question 7

coelomate

Answer 7

body cavity within mesoderm

Question 8

acoelomate

Answer 8

no fluid filled body cavity

Question 9

pseudocoelomate

Answer 9

have a body cavity, but not wrapped on both sides with mesoderm

Question 10

why was segmentation beneficial?

Answer 10

• allowed for specialization of regions

- helped control movement

Question 11

what role did locomotion play in the Cambrian explosion (“explosion of diversity”)

Answer 11

• beneficial for
• –finding food and mates
• –avoiding predators
• movement led to a huge increase in the need for energy which in turn led to predator-prey coevolution

Question 12

what was the common ancestor of animals

Answer 12

-colonial flagellate protist

Question 13

describe platyhelminthes

Answer 13

flatworms, dorsoventrally flattened, blind gut

Question 14

describe rotifers

Answer 14

very small, complete gut, pseudocoel, cilia

Question 15

describe bryozoan

Answer 15

moss animals, filter feeders, 1-2 mm, form colonies, sessile

Question 16

describe brachiopods

Answer 16

• two part shells

- peaked in paleozoic and mesozoic (450 species left)

Question 17

brachiopod shell

Answer 17

• two shell halves are dorsal and ventral

- resemble bivalve mollusks but shell is product of convergent evolution

Question 18

what are the classes within phylum mollusca?

Answer 18

polyplacophora, gastropoda, bivalves, cephalopoda

Question 19

polyplacophora

Answer 19

chitins

Question 20

gastropoda

Answer 20

snails, slugs

Question 21

bivalves

Answer 21

clams, oysters, scallops

Question 22

cephalopoda

Answer 22

squids, octopuses, chambered nautilus

Question 23

what is the visceral mass

Answer 23

mass containing heart, digestive, excretory, and reproductive

Question 24

describe polyplacophora

Answer 24

chitins

• 8 calcareous plates (protection)
• marine
• use radula for feeding (scapes rocks)
• clings to rocks with muscular foot

Question 25

describe gastropoda

Answer 25

snails and slugs - some are toxic - only mollusks that live in terrestrial habitat

Question 26

describe bivalves

Answer 26

clams, oysters, scallops, and mussels - 30,000 species - hinged, two part shell, use foot to burrow into sand - feed with siphon

Question 27

describe siphon feeding

Answer 27

- water and food in through incurrent siphon | - water out through excurrent siphon

Question 28

describe cephalopods

Answer 28

squids, octopus, chambered nautilus - modified excurrent siphon - eyes similar to vertebrates - use arms and tentacles to capture food - most retain small internal shell for support - -pen

Question 29

modified excurrent sipon allows for

Answer 29

jet propulsion

Question 30

what are the classes within phylum annelida?

Answer 30

oligochaetes, polychaetes, hirudinea

Question 31

oligochaetes

Answer 31

earthworms

Question 32

polychaetes

Answer 32

mostly marine worms

Question 33

hirudinea

Answer 33

leeches

Question 34

describe oligochaetes

Answer 34

earthworms - don't have parapodia, eyes, or tentacles - few setae - burrow in and digest soil - hermaphroditic

Question 35

describe polychaetes

Answer 35

- marine - burrowing - parapodia on each segment

Question 36

describe hirudinea

Answer 36

leeches - lack parapodia - no obvious segments - suckers

Question 37

list the unifying characteristics of ecdysozoans

Answer 37

- cuticle - shed their cuticle to grow - "molting" evolved only once - all have single common ancestor

Question 38

nematoda includes

Answer 38

roundworms and horsehair worms

Question 39

how do ecdysozoans grow

Answer 39

molting

Question 40

describe roundworms

Answer 40

- gas exchange through cuiticle - moist environ - abundant - microscopic - elphatiasis

Question 41

describe horsehair worms

Answer 41

- thin - can grow up to a meter long - larvae are intestinal parasites of insects

Question 42

describe tardigrades

Answer 42

water bears - 8 fleshy legs - live in sands and water films on plants and lichens

Question 43

describe onchyophorans

Answer 43

velvet worms - live in decomposing leaves in humid tropics - resemble arthropod ancestors

Question 44

describe arthropod exoskeleton

Answer 44

- cuticle - made of chiton - protects from dessication and predators

Question 45

describe arthropods

Answer 45

- exoskeleton - muscles attached to exoskeleton - segmented - jointed appendages

Question 46

describe chelicerates (subphylum)

Answer 46

- merostomata (horseshoe crabs) - arachnida (spiders, scorpions, ticks) - mouthpart appendages (chelicerae) - four pairs of walking legs

Question 47

describe chelicerae

Answer 47

for grasping, inject venom

Question 48

myriopods classes

Answer 48

- chilopoda | - diplopoda

Question 49

myriopods have what instead of chelicerates

Answer 49

mandible

Question 50

chilopoda

Answer 50

centipedes (2 leg/segment)

Question 51

diplopoda

Answer 51

millipedes (4 leg/segment)

Question 52

describe crustacea

Answer 52

marine, freshwater, and terrestrial | shrimp, lobster, crabs, and barnacles

Question 53

describe hexapoda

Answer 53

class insecta, segmented, head has one pair of antennae, thorax has three pairs of legs and two sets of wings, abdomen doesn't have appendages, nerve cord