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Flashcards in deuterostomes Deck (27):
1

deuterostomes phylum

echinoderm
hemicordates
chordates

2

deuterostome properties

mouth derives from second opening

3

distinctionb etween deuterosomtes and protostomes

is becoming fuzzy;
prosostomes, ecdysozoa and lophotrochozoa all clearly a monophyletic group;

not all prostomes are spiral cleavers

not all prosostomes prosostomes

4

examples of non-protostomes protostomes

chaetognaths(lophotrophozoa) and priapulids (ecdysozoa)

(develop secondary mouth)

5

trimery

having 3 segments; usually a deuterostome feature
-could be a primtiive characteristics of triplomblasts lost in prostostomes

6

first triploblast

probably a deuterostosome as Braciopods develop similarliy but are prostomes due to de-volution

7

scientific confusion aboout lophophores

are the protostomes? (ribosomal dna evience) but have tri-partheid body of a deuterostome

8

annelids rigdea worm

is made up of three segments

9

previousally classifed deuterostomes


chateongraphs (now lophotrophozoa)

bracio pods

annelids

telophores

10

brachiopods

similar prostomes charteristics

11

chaetographs


are lophotrophozoa; ; had similar characteristics (trimery and radial cleavage) but were reclassified due to genome sequence

12

abulacrania

clade consisting of echinoderms and hemicordhates

13

echinoderm examples

star fish and sea urchin

14

hemichordate example

worms

15

chordate examples

vertebrates such as apes

16

popular belief about deuterostomes

that they started as sessil filter feeders (similar to echinoderms) and then developed into hemichordates as free swimming larvae and eventually complexified into vertebrates (not true tho)

17

truth about deuterstome-conception development

-echinoderms are the first despite being simple
-hemichordates arent a sistergroup of chordates, instead echinoderms and hemichorates more embryologically similar
- larvae comparisons shows echinodersm and hemichordates are closely related

18

echinoderms and hemichordates

- closeley related; molecular data shows similar larvae and embryological stages
-similar nervous systems

19

calcihodrate

stylophoria; disputed for long time but are an early echinoderm fossil

fould out by characteristics of echindoerm of mineralized skeleton that forms a spong like mesh; stereom catalatic endoskeleton similar to sea urchin skeleton

20

chordates and hemichordates

have mouths where water enteres and slips into gills

these pharangeal slits found in fossilied echindoerms

21

urochordates

used to be classified as molluscs but actually chordates due to embryologically similarities

are sessile filterfeers

eggs are tadpole larvae; fish like and have notochords

have dorsal nerve cord, pharyngeal slits, anus and post anal tai and are muscular segmented

22

cephalochordates

also have notocord and stiffening rod for rigid muscles and dorsal nerve cord

fishliked and usualyl filter feed

23

truth about urochordates, cephalochordates and vertebrates

urochodates more closely related to vertebrates than fish like cephalochordates

-ancestor of urochordates more complex but have lost charateristics from active predator to passive filter feeder

hence vertebrates + urochordates form a clade and cephalochordates are a sister group

24

inversion of dorsoventral axis

vertebrates have a dorsal nerve cord; invertabrates have a ventral nerve cord BECAUSE at one point in history vertebrates flipped over

25

flipping of verterbrates

during cambrian era; changed nerve cord position

thats why flies and toads have similar gene express (chord BMP4 gene) but expressed on flys back and toadas belly

26

possible fourth deuterostome group?

xenoturbella and aceolomorphs not related to platyhelminth but are outside tribloblasts; hence maybe branched early or developed?

27

what was urbilateria

could have been a deuterstome