Clade Bilateria

Question 0

Phylum acoelomorpha?

Answer 0

Distinct anteroposterior axis but no brain
Radial nerve arrangement
Mostly in marine sediment

Question 1

Clade bilateria?

Answer 1

All members exhibit primary bilateral symmetry
Also have cephalization
More active lifestyle requires a different form->form is related to function
All are triploblastic

Question 2

Phylum Platyhelminthes?

Answer 2

Typically flattened bodies
4 classes
1 free living, the rest are parasitic

Question 3

Platyhelminthes tegument and muscles?

Answer 3

Free living class have ciliated epidermis
Contain rhabdites-form protective mucous sheath
Also dual gland adhesive organs for locomotion via attachment and disattachment
Parasitic class have tegument with no cilia
Layers of muscle fibres grow diagonally, longitudinally and circularly
Parenchyma fills in between spaces

Question 4

Platyhelminthes nerve system and sense organs?

Answer 4

Cephalization but vary in complexity
Most simple is sub epidermal nerve net plexus
Others have longitudinal nerve cords
“Brain” mass of ganglion cells->differentiation of neurons into types
Abundant tactile and chemoreceptive cells
Form organs (auricles) in Platyhelminthes
Statocysts for equilibrium
Eye spots (ocelli) in some

Question 5

Nutrition and digestion in Platyhelminthes?

Answer 5

Mouth, intestine and pharynx
Extra cellular digestion via intestinal secretions
Infra cellular digestion after intestinal cells undergo phagocytosis
Undigested food expelled via pharynx (blind gut).

Question 6

Excretion for Platyhelminthes

Answer 6

Canals with tubules ending in flame cells
Flagella beat to create negative pressure that will draw fluid in
Collecting ducts open to outside via pores
Metabolic waste excreted by diffusion through body wall

Question 7

Reproduction for Platyhelminthes?

Answer 7

Many via asexual and sexual means
Asexual reproduction via regeneration
Parent constricts in middle
Each half generates missing end
Parasitic flukes reproduce asexually in mollusc intermediate host
Also sexual reproduction via cross fertilization (even though monoecious)

Question 8

Clade Turbellaria

Answer 8

Mostly free living flat worms
Fresh water predator of smaller animals
Contain planarians
Form a paraphyletic group

Question 9

Clade Trematoda?

Answer 9

All parasites
Various structural adaptations depending on environment
3 subclasses: Digenea, Monogenea, Cestoda

Question 10

Subclass Digenea?

Answer 10

Many with complex life cycles
Alternating sexual and asexual stages
Intermediate and final hosts
(Parasitic castration)

Question 11

Schistosoma?

Answer 11

Very good defences to evade immune system
Mimic host surface proteins
Release molecules to manipulate immune system
Live in veins of bladder, liver..etc

Question 12

Bird schistosomes?

Answer 12

Swimmers itch

Question 13

Class Monogenea?

Answer 13

Mostly external parasites of fish
Clamp on using hooked attachment organ (opisthaptor)
Simple life cycle
Widespread and common

Question 14

Class Cestoda?

Answer 14

All internal parasites
Long flat bodies of repeating segments (proglottids) with a scolex for attaching to host
Over 4000 species!
No gut and absorb nutrients across body surface

Question 15

Phylum Mesozoa?

Answer 15

Tiny, ciliated
2 cell layers not homologous to germ layers
No gastrulation during development
Highly specialized parasites or symbionts

Question 16

Phylum Nemertea?

Answer 16

Thread ribbon worms
Long muscular proboscis 
Ciliated epidermis with gland cells
Flame cells for excretion
Almost all marine

Question 17

Nemertea locomotion?

Answer 17

Circular and longitudinal muscles

Usually glide over slime track

Question 18

Nemertea digestion?

Answer 18

Seize prey with proboscis contained within rhyncocoel
Cavity entirely within mesoderm- true coelomate
Eversion exposes sharp barbs (stylets) that stab and inject neurotoxins
Esophagus thrust through mouth to engulf prey
Digestion system complete
Cilia help move food through intestine

Question 19

Nemertea circulation?

Answer 19

Have true circulatory system with blood
Vessels contract to keep up flow
Flame bulb protonephrenia are associated
True excretion vs osmoregulation

Question 20

Nemertea sensory?

Answer 20

Pair of nerve ganglia

Nerve cords connected by transverse nerves

Question 21

Nemertea reproduction?

Answer 21

Some asexually by fragmentation or regeneration

Others sexually~dioecious

Question 22

Clade Turbellaria

Answer 22

Mostly free living flat worms
Fresh water predator of smaller animals
Contain planarians
Form a paraphyletic group

Question 23

Clade Trematoda?

Answer 23

All parasites
Various structural adaptations depending on environment
3 subclasses: Digenea, Monogenea, Cestoda

Question 24

Subclass Digenea?

Answer 24

Many with complex life cycles
Alternating sexual and asexual stages
Intermediate and final hosts
(Parasitic castration)

Question 25

Schistosoma?

Answer 25

Very good defences to evade immune system
Mimic host surface proteins
Release molecules to manipulate immune system
Live in veins of bladder, liver..etc

Question 26

Bird schistosomes?

Answer 26

Swimmers itch

Question 27

Class Monogenea?

Answer 27

Mostly external parasites of fish
Clamp on using hooked attachment organ (opisthaptor)
Simple life cycle
Widespread and common

Question 28

Class Cestoda?

Answer 28

All internal parasites
Long flat bodies of repeating segments (proglottids) with a scolex for attaching to host
Over 4000 species!
No gut and absorb nutrients across body surface

Question 29

Phylum Mesozoa?

Answer 29

Tiny, ciliated
2 cell layers not homologous to germ layers
No gastrulation during development
Highly specialized parasites or symbionts

Question 30

Phylum Nemertea?

Answer 30

Thread ribbon worms
Long muscular proboscis 
Ciliated epidermis with gland cells
Flame cells for excretion
Almost all marine

Question 31

Nemertea locomotion?

Answer 31

Circular and longitudinal muscles

Usually glide over slime track

Question 32

Nemertea digestion?

Answer 32

Seize prey with proboscis contained within rhyncocoel
Cavity entirely within mesoderm- true coelomate
Eversion exposes sharp barbs (stylets) that stab and inject neurotoxins
Esophagus thrust through mouth to engulf prey
Digestion system complete
Cilia help move food through intestine

Question 33

Nemertea circulation?

Answer 33

Have true circulatory system with blood
Vessels contract to keep up flow
Flame bulb protonephrenia are associated
True excretion vs osmoregulation

Question 34

Nemertea sensory?

Answer 34

Pair of nerve ganglia

Nerve cords connected by transverse nerves

Question 35

Nemertea reproduction?

Answer 35

Some asexually by fragmentation or regeneration

Others sexually~dioecious