Bio final chapter 22

Question 1

Clade Bilateria

Answer 1

contains two main groups protosomes and deutrosomes, bilateral symmetry plan and triploblastic

Question 2

Bilateral symmetry helps with what

Answer 2

directional mobility, cephalisation formation of head,

Question 3

Bilateria most basal phylum

Answer 3

phylum acoela,
characteristics
-small flattened body, minimal cephalization and simple nerve net (lack brain)
-absence of body cavity or complex organs
-simple digestive system-only mouth no gut, or anus, digestion happens within cells

Question 4

Lophotrochozoa clade

Answer 4

half of animal phyla
no unifying synapomorphy
presence of lophophore in some taxa
presence of trochopore at larval stage
diverse body plans

Question 5

Platyhelminthes lophotrochozoa

Answer 5

flatworms, triploblastic lack body cavity
mouth and gut but no anus
absence of circulatory or gas exchange

Question 6

Platyhelminthes lophptrochozoa rhabditophorans

Answer 6

parasitic
suckers or hooks
tough outer layer
life cycle with two hosts
intermediate host- sexual repro
definitive host-asexual
termatodes (flukes) and tapeworms

Question 7

Lophotrochozoa- lophophorata

Answer 7

Have lophophore for feeding ciliated tenticles around mouth
includes ectoprocta and brachiopoda

Question 8

Lophorata- ectoprocta

Answer 8

sessile
hard exoskeleton secreting CaCo3
retractable lophophore
U shaped digestive tract
both sexual and asexual (budding)

Question 9

Lophorata- brachiopoda

Answer 9

sessile suspension feeders
attached to seafloor by stalk (pedicle)
use retractable lophophore for feeding
digestive tract with or without anus

Question 10

Lophorata- Trochozoa

Answer 10

phylum annelida and molluscs
share
-patterns of early embryonic development
-microscopic, motile, trochophore larvae-planktonic larvae with cilia for suspension feeding
-sensory plate with simple eyespot above band

Question 11

Trochozoa molluscs unsegmented body plan

Answer 11

snails, slugs oysters, clams, octopuses and squids
soft bodied but protected by hard calcerous shells unsegmented body plan
-muscular ventral foot for locomotion
-visceral mass dorsal to foot with internal organs
-coelom is reduced and mass is within haemocoel
-thin layers of tissue called mantle
-calcerous shell secreted from mantle

Question 12

molluscs gas exchange

Answer 12

through gills in mantle cavity

Question 13

molluscs feeding

Answer 13

rasplike radula (cutting food)

Question 14

Molluscs circulatory system

Answer 14

open circulatory system
haemolymph is circulated into and out of the heart

Question 15

Molluscs have

Answer 15

dioecious and hermaphrodite taxa

Question 16

larval stage molluscs

Answer 16

trochopore

Question 17

Phylogeny of molluscs

Answer 17

Polyplacophora (chitons)
cephalopoda (squids octopuses)
bivalvia (clams oysters)
gastropoda (snails and slugs)

Question 18

Polyplacophora and what is it

Answer 18

molluscs
chitons
muscular foot functions like suction cup adhered to rocks
body protected by 8 dorsal plates

Question 19

Cephalopoda

Answer 19

squids octopuses …
absence of external shell
presence of siphon fused from tubes of mantle
long tenticles around mouth
radula is modified into beak
closed circulatory system
complex brain and sensory organs
absence of trochophore larvae

Question 20

Bivalvia

Answer 20

some taxa sessile (marine muscles)
some sedentary (scallops)
some bivalves can dig with muscular foot or swim by clapping shells
two halves connecyed by abductor muscle
some eyes or sensory tenticles
absence of cephalisation
absence of radula
suspension feeders in gills in mantle cavity

Question 21

gastropoda

Answer 21

snails and slugs
aquatic have trochophore larvae
terrestrial have direct development
single coiled tubular shell
strong cephalisation

Question 22

trochozoa annelida

Answer 22

marine and freshwater species
two clades errantia and sedentaria
segmented bodies seperated internally by septa
coelom as hydroskeleton
complete digestive system
closed circulatory system

Question 23

Trochozoa annelida errantia

Answer 23

mobile predatory
pair of parapodia per body segment
parapodia have numerous chateau and bristles composed of chitin also associated with gills
cephalisation with head antennae and eyes
sexual reproduction and external fertilization which leads to trochophore larvae

Question 24

Annelida sedentaria

Answer 24

leeches and earthworms
less mobile
some taxa burrow into substrates other live in protective tubes
tube dwelling often have elaborate gills or tentacles used for suspension feeding
NO parapodia
cephalisation with head eyes antennae
some taxa lack larvae stage