Deuterostomes

Front 1

Characteristics

Back 1

o Radial cleavage
o Formation of mouth opposite end of embryo from blastopore
o Development coelom from mesodermal pockets. Bud from gastrula instead splitting of mesoderm like in protostomes
o Common ancestor – bilaterally symmetrical, pharyngeal slits
o Tripoblastic, coelomate animals, internal skeleton

Hint 1

5 major

Front 2

Major Groups

Back 2

o Echinoderm- sea star, sea urchin
o Hemichordate- acorn worm, pterobranchs
o Chordates- sea squirt, lancelet, vertebrates

(echinoderm +hemichordate similar)

Front 3

Echinoderm Symmetry

Back 3

-pentaradial symmetry
-larvae bilaterally symmetry (anterior and posterior orientation from tool kit genes), turn to pentaradial symm.
-have oral/aboral side. No head, move equally well in all directions

Hint 3

normal + larvae

Front 4

Seastars (Echinoderm)

Back 4

-each arm seastar expresses tool kit genes as if individual.
-develops as 5 bilaterally symmetry organism attatched to stomach.
-gonad+organs in arms, tube feet have ampulla used for locomotion, move w/ circular+ longitudinal muscular contraction. Feeds by push stomach out through mouth, secreting enzymes digest prey.

Hint 4

yunnanozoa has same characteristic as 1 arm sea star

Front 5

Skeleton Echinoderm

Back 5

-internal calcified skeleton surrounded by thin layers skin and muscles. allows for continuous growth.

Front 6

Sea Urchin

Back 6

-calcated spines poking through dermis and tube feet.

Front 7

Water Vascular system
(echinoderms)

Back 7

apparent in all echinodermata

-water sucked in through madroporite esophagus -> ring canal -> and pressure created yields tube feet
-tube feet used for feeding, locomotion, respiration.

Front 8

Sea Cucumbers

Back 8

-echinoderm
-pentaradially symmetry tube feet
-lost endoskeleton

Front 9

Hemichordata

Back 9

o Hemichordates have 3 part body plan - Proboscis, collar (mouth), trunk (other body parts)
-Acorn worm- Mouth behind pharynx and intestine, pharyngeal slits Pump water through mouth, out through slits allow breathing
-difficult place in taxa-could be echinoderm but no notochord.
-Pterobranchs
• Sedentary marine animals, live in tube of proboscis.

Hint 9

major group deuterosomes
closely related to echinoderm

Front 10

Chordates (cephalochordata, urochordata, vertebrae)

Back 10

-notochord, pharyngeal gill slits, dorsal hollow nerve cord.

-notochord from mesoderm
-nerve cord comes from ectoderm (neural tissue)
-pharynx from endoderm

Front 11

Urochordata (chordata)

Back 11

-no notochord, dorsal hollow nerve but gill slits.
-"tail chordate"
-sea squirts-90%-take in water through incurrent siphon, and out through excurrent siphon. (passes by gill slits) pharyngeal basket filters prey from water.
-larva has dorsal, hollow nerve cord + notochord in tail. Swim in plankton, then settle on seafloor transform into sessile adult.

Front 12

Cephalochordata (chordata)

Back 12

• Small animals. Notochord used in burrowing (extneds into head), lie covered in sand with mouth at surface. Eat with pharyngeal baskets
-lancelets
-related to vertebrates
lack embryonic tissue layer

Front 13

Vertebrate characteristic

Back 13

-chordate characters
-neutral crest from cells adjacent to neural tubes (ectoderm) form skull (synapomorphy)
-carilage, bone, dentine
-vertebral column (mesoderm) replace notochord. Mesoderm is majority of volume
-somites-formed from mesoderm forming skin, muscle, cartilage, muscle, ribs.

Front 14

brain

Back 14

multiplication of ectodermal cells

Front 15

Lamprey (type vertebrae)

Back 15

no jaw, suction mouth, visceral skeleton evolved form vertebrate jaw. each segment is visceral arch. lamprey have 7 visceral arches. neural crest -> teeth(dentine which is enamal from ectoderm). true vertebrae w/ complete metamorphosis