week 8c

Question 1

3 main groups within Bilateria

Answer 1

protostomia (lophotrochozoa and ecdysozoa) and deuterostomia

Question 2

what is a key trait of Bilaterians

Answer 2

bilateral symmetry and typically triploblastic (3 germ layers)

Question 3

what does “Lophotrochozoa” mean

Answer 3

lophos = crest (refers to lophophore)
troch = wheel (refers to trochophore larva)

Question 4

what are 2 key features are often found in Lophotrochozoa

Answer 4

Lophophore: Ring of ciliated feeding tentacles (seen in bryozoans, brachiopods, phoronids)

Trochophore larva: Free-swimming larval stage with bands of cilia (seen in mollusks and annelids)

Question 5

are both features (lophophore and trochophore) always present in all lophotrochozoans?

Answer 5

no, some phyla may have one, the other or neither and classification is based on molecular data

Question 6

what does “ecdysozoa” refer to

Answer 6

ekdero = “to strip off skin” - refers to ecdysis or molting of a cuticle

Question 7

what is the key feature of ecdysozoans

Answer 7

they have an external skeleton or cuticle that they molt to grow

Question 8

what distinguishes deuterostomes from protostomes in development

Answer 8

deuterostomes = mouth develops after anus
protostomes = mouth develops first

Question 9

are flatworms coelomates, pseudocoelomates or acoelomates

Answer 9

acoelomates = they lack a body cavity

Question 10

what are the 3 germ layers in platyhelminthes and what do they form

Answer 10

endoderm = digestive cavity with specialized cells
mesoderm = muscles and reproductive organs
ectoderm = ciliated epidermis, nervous system, excretory (flame cell) system

Question 11

do flatworms include parasitic species

Answer 11

yes - they both include free-living and parasitic species

Question 12

what unique structure do rotifers use for feeding and locomotion

Answer 12

a ciliated crown (corona)

Question 13

which phyla are united by the presence of a lophophore

Answer 13

bryozoa, brachiopoda and phoronida

Question 14

what is a lophophore

Answer 14

a ciliary feeding structure that also aids in gas exchange

Question 15

do lophophorates have a true coelom

Answer 15

yes

Question 16

what is the shape of their alimentary canal and location of the anus

Answer 16

u-shaped canal with the anus outside but near the mouth

Question 17

are bryozoans solitary or colonial

Answer 17

colonial, often encrusting rocks or boat hulls

Question 18

what is a zoecium

Answer 18

a chitin or calcium carbonate structure each bryozoan

Question 19

how big are most bryozoans

Answer 19

less than 0.5 mm long

Question 20

how do brachiopods resemble clams

Answer 20

they have 2 shells, but they are dorsal and ventral (top and bottom) unlike clams’ left/right orientation

Question 21

how do brachipods attach to surface

Answer 21

using a muscular pedicle

Question 22

were brachiopods more common in the past

Answer 22

yes - especially during the paleozoic and mesozoic eras

Question 23

what are main body components of mollusks

Answer 23

head-foot, visceral mass, mantle and often a redula

Question 24

do mollusks have seprate sexes

Answer 24

mostly though some are hermaphroditic

Question 25

what type of fertilization occurs in mollusks

Answer 25

can be internal or external

Question 26

what is unique about bivalvia

Answer 26

2-part hinged shell, filter feeders with sophons

Question 27

what characterizes Polyplacophora (chitons)

Answer 27

marine mollusks with 8-plated shells

Question 28

what is notable about gastropoda

Answer 28

coiled shells; radula present; found in marine, freshwater or terrestrial habitats

Question 29

what defines Cephalopoda

Answer 29

marine predators with tentacles, closed circulatory system and jet propulsion

Question 30

what features support annelids on land

Answer 30

a cuticle for support and water retention

Question 31

what does cuticle allow annelids to do

Answer 31

colonize dry environments and function as a light external skeleton

Question 32

what is their method of reproduction

Answer 32

typically internal fertilization

Question 33

what does "nematoda" mean

Answer 33

"thread" - referring to their thread-like shape

Question 34

what environments do nematodes thrive in

Answer 34

many are microscopic, live on soil, or parasitize plants/animals

Question 35

name 3 parasitic nermatodes and their effects

Answer 35

1. hookworm 2. pinworm 3. wuchereia bancrofti (causes elephantiasis)

Question 36

what does arthopoda mean

Answer 36

jointed foot = refers to their jointed appendages

Question 37

what are key features of arthopods

Answer 37

segmented bodies, specialized appendages, and a chitinous exoskeleton

Question 38

what functions does the exoskeleton serve

Answer 38

protection, support and prevents dehydration

Question 39

what is the process of shedding the exoskeleton called

Answer 39

ecdysis (molting)

Question 40

what organisms are in subphylum chelicerata

Answer 40

spiders, scorpions, mites, ticks, horeshoe crabs, sea spider

Question 41

what are the body regions of chelicerates

Answer 41

cephalothorax (fused head/thorax) and abdomen

Question 42

what are chelicerae

Answer 42

1st pair of appendages, often used as fangs ro claws

Question 43

how many pairs sof appendages do they have

Answer 43

6 pairs = 4 pairs of legs = 1 pair chelicerae = 1 pair of pedipalps

Question 44

are chelicerates mostly terrestrial or aquatic

Answer 44

mostly terrestrial and they are typically predatory or parasitic

Question 45

what animals are in myriapoda

Answer 45

millipedes and centipedes

Question 46

what is the body strcuture of myriapods

Answer 46

head plus a highly segmented trunk

Question 47

how do millipedes and centipedes differ

Answer 47

m = 2 pairs legs per segment = herbivorous c = 1 pair legs per segment = predatory with posion jaws

Question 48

are myriapods terrestrial or aquatic

Answer 48

terrestrial

Question 49

what organisms belong to crustacea

Answer 49

crabs, lobsters, shrimp

Question 50

what are key features of crustaceans

Answer 50

- hardened exoskeleton - 2 pairs antennae - split into 2 branches - specialized body segments for different functions

Question 51

where do most crustaceans live

Answer 51

marine environments

Question 52

what animals are in hexapoda

Answer 52

insects

Question 53

what is the body plan of hexapods

Answer 53

3 regions = head, thorax, abdomen

Question 54

how many legs/wings do hexapods have

Answer 54

3 pairs legs, usually 2 pairs wings

Question 55

what are hexapods mouthparts specialized for

Answer 55

biting, chewing, sucking or lapping

Question 56

what is their primary habitat

Answer 56

mostly terrestrial some in freshwater

Question 57

what types of diets do they have

Answer 57

herbivorous, parasitic or predatory