Week 4

Question 1

radial symmetry

Answer 1

animals that have an axis that runs from mouth to base, with many planes of symmetry around the central axis
allows them to move up and down in water column and sweep food from many directions at once
cnidarians

Question 2

bilateral symmetry

Answer 2

bodies have distinct head and tail and single plane of symmetry running between them at midline
horizontal movement and developed specialised sensory organs
organ systems
insects

Question 3

simplest animals

Answer 3

cnidarians
sponges
ctenophores
placozoans

Question 4

sponges

Answer 4

multicellular
interior surface lined by cells called choanocytes
intracellular digestion
spicules for skeleton
mesophyl between interior and exterior cell layers: nutrients and amoeba like cells for skeleton formation

Question 5

cnidarians

Answer 5

life cycle alternates between sea anemone and jellyfish
predators- catch prey with tentacles and digest it in the gastric cavity
reproduce asexually
diploblastic
gastric cavity digests and excretes

Question 6

ctenophores

Answer 6

resemble cnidarians in body plan 
radial symmetry 
predators- ingestion 
propel by cilia 
rudimentary gonads

Question 7

bilateral animals

Answer 7

lophotrochozoans
ecdysozoans
deuterostomes
chordates

Question 8

lophotrochozoans

Answer 8

spiral cleavage early in development 
annelids worms and mollusks 
predators or ingest sediments 
mollusks
gastropods, cephalopods, bivalves

Question 9

ecdysozoans 8 phyla

Answer 9

nematodes 
arthropoda 
chelicerates 
myriapods 
crustacenas 
insects

Question 10

deuterostomes 3 phyla

Answer 10

hemichordata
echinodermata
chordata

Question 11

hemichordata

Answer 11

wormlike

move through sea floor and collect food particles

Question 12

echinoderms

Answer 12

skeletons made of porous calcite

tube feet

Question 13

chordates

Answer 13

vertebates
pharynx with pharyngeal slits
body musculated arranges in segments called myotomes
cephalochordates and tunicates
notochord: stiff rod of collagen that runs along back

Question 14

3 subphyla of chordates

Answer 14

cephalochordates
tunicates
vertebrates AKA craniates

Question 15

fish

Answer 15

earliest branching vertebrates

earliest branching craniates are hagfish and lampreys

Question 16

lampreys

Answer 16

vertebrae of cartilage

lack jaw

Question 17

hagfish

Answer 17

lacks vertebrae
lack jaw
soft foods

Question 18

chondrichthyes

Answer 18

sharks

deposit calcium phosphate only in teeth and denticles in skin

Question 19

osteichthyes

Answer 19

bony fish
cranium 
jaws 
bones mineralised by calcium phosphate 
swim bladder

Question 20

amniotes

Answer 20

lack heavy jaw
amniotic egg has dessication resistant shell and four membranes for gas exchange and waste
mammals, marsupials, placental mammals

Question 21

mammals

Answer 21

covered with hair and feed milk from mammary glands

Question 22

marsupials

Answer 22

young born at early developmental stage

pouch with mammary glands

Question 23

placental mammals

Answer 23

placenta develops in uterus to provide nutrition

Question 24

cambrian period

Answer 24

541-485 MYA

body plans most like bilateral

Question 25

ordovician period

Answer 25

485-443 MYA

evolution of heavily skeletonised animals in ocean

Question 26

animals began to colonise the land

Answer 26

420 MYA

Question 27

organisms most closely related to animals

Answer 27

choanoflagellates

Question 28

bilateria

Answer 28

triploblastic

protosomes and deuterostomes

Question 29

protosomes

Answer 29

blastopore becomes mouth

Question 30

deuterostome

Answer 30

blastopore becomes anus

Question 31

placozoans

Answer 31

no specialised tissue
cells arranged into upper and lower epithelia that enclose interior fluid
cilia for movement
similar genome to cnidarians and bilateral animals

Question 32

order of divergence

Answer 32

choanoflagellate 
sponges 
sponges 
ctenophores 
placozoans 
cnidarians 
bilaterians

Question 33

dendrogramma

Answer 33

some characteristics like cnidarians and ctenophores

Question 34

annelid

Answer 34

cerebral ganglion NS

digestive system and anus

Question 35

aquatic annelid

Answer 35

gill like organs
water filtering organs called nephridia gonads
coelom

Question 36

mollusks

Answer 36

mantle for breathing and excretion
larvae called trochophore
gastropods, cephalopods, bivalves

Question 37

gastropods

Answer 37

type of mollusk
mouth has radula for feeding
coelomates
predators

Question 38

cephalopods

Answer 38

class of mollusk
tentacles to capture prey and sense environment
propulsion in water

Question 39

bivalves

Answer 39

group of mollusk
no heads
two hard shells
filter food from water

Question 40

ecdysozoans

Answer 40

process of ecdysis or melting

secrete a protein rich coating that covers their bodies

Question 41

our closest invertebrate relatives

Answer 41

tunicates

Question 42

permian period

Answer 42

252 MYA

Environmental catastrophe eliminates most genera in oceans