Introduction to deuterostomes

Question 0

Deuterostomes

Answer 0

an animal whose anus is formed from the blastopore. mouth develops later

Question 1

three major taxa (phyla)

Answer 1

Hemichordata
Echinodermata
Chordata

Question 2

Name of common ancestor and charactetistics

Answer 2

Yunnanozoon

• bilaterally symmetrical
• segmentation
• pharynx with slits

Question 3

Hemichordates

Answer 3

worm-like marine animals

• 3 part body plan (proboscis, collar, and trunk)
• burrow in mud or sand in marine habitats have pharyngeal slits

Question 4

Pharyngeal slits

Answer 4

water enters mouth and exits via slits pharynx used for gas- exchange and respiration

Question 5

Echinoderms

Answer 5

sea stars, sea cucumbers, sea urchins

- all marine

Question 6

Characteristics of echinoderms

Answer 6

1. pentaradial symmetry (adult)
2. water vascular system
3. tube feet, spines
4. endoskeleton of calcareou ossicles
5. bilaterally symmetrical when they are larvae

Question 7

Binmpimaria

Answer 7

early stage of echinoderms

Question 8

Brachiolaria

Answer 8

later larvae stage

branchy

Question 9

The sister taxa of protostomes

Answer 9

deuterostomes

Question 10

pentaradial symmetry

Answer 10

• unique to echinoderms

- body parts arranges radially in 5 or multiples of 5

Question 11

water vascular system

Answer 11

• unique to echinoderms
• fluid filled canals and tube feet that function hydraulically for locomotion, feeding, and respiration
• water enters through madreporite

Question 12

tube feet and spine

Answer 12

tube feet usually in grooves
-function in locomotion and feeding

spines: projections on surface that function in protection, give echinoderms their name

Question 13

endoskeleton of calcareous ossicles

Answer 13

may be fused (sea urchins and sand dollars)

-may be dispersed ( sea cucumbers and sea stars)

Question 14

Ophiuriods

Answer 14

• brittle stars
• move by bending 5 flexible, articulated arms (tube feet not used for locomotion)
• mostly suspension feeders, hold arms up to trap particles on sticky tube feet

Question 15

Asteroids

Answer 15

• sea stars
• movie with tube feet
• all predators
• ecologically important

Question 16

reproduction in sea stars

Answer 16

sexual
-separates sexes, mostly broadcast spawn
asexual
- regenerative ability
-can divide at central disc and regenerate missing have or regenerate a new individual from an arm
-larvae can reproduce through budding

Question 17

Echinoids

Answer 17

sea urchins

• move with tube feet that extend between spines
• large, movable spines for protection
• herbivores, feed on large algae

Question 18

Holothuroids

Answer 18

sea cucumber/ sea pig

• move via rows of tube feet on ventral side
• suspension or deposit feeders; capture/collect particles with branching tube feet around the mouth
• eviscerate to escape predators

Question 19

Crinoids

Answer 19

feather stars

• oldest group of living echinoderms
• sessile suspension feeders; catch particles on sticky tube feet extending from grooves on the “feathery” arms

Question 20

Chordata

Answer 20

• all bilaterally symmetrical, coelomate and segmented

- monophyletic clade that includes vertebrates and 2 clades of invertebrates

Question 21

4 key traits of chordates

Answer 21

1. notochord
2. pharyngeal slits
3. dorsal, hollow nerve cord
4. muscular, post-anal tail

Question 22

notochord

Answer 22

flexible rod-like structure composed of large, fluid filled cells

Question 23

dorsal, hollow nerve cord

Answer 23

spinal chord in humans

Question 24

Muscular, post-anal tail

Answer 24

tail extends posterior to the anus

Question 25

Cephalochordata

Answer 25

- invertebrate - all marine, look like tiny transparent fish - burrow in sediment with mouth sticking out - suspension feedes- draw water into mouth and through pharyngeal slits

Question 26

Urochordata

Answer 26

- invertebrate - all marine, some sessile, others free-swimming - solitary and colonial species with tadpole-like larval stage - notochord, dorsal hollow nerve cord, and post anal tail ONLY in larval stage

Question 27

3 clades of urochordata

Answer 27

ascidians thaliaceans larvaceans

Question 28

Ascidians

Answer 28

sea squirts - have secreted exoskeleton (tunic) of cellulose-like material - have a brachial basket (perforated pharynx), water enters through oral siphon, food filtered to digestive system, waste ejected from atrial siphon - tadpole larvae can swim, but adults are all sessile suspension feeders

Question 29

Thaliaceans

Answer 29

salps - like free-floating adult ascidians - some are solitary, others form enormous colonies - all are effective suspension feeders

Question 30

Larvaceans

Answer 30

- like tadpole larvae (retain tail and notochord as adults) - live in mucus house they contruct - suspension feed by beating tail to pump water through house, food gets trapped in mucus, both food and mucus ingested

Question 31

Vertebrata

Answer 31

synapomorphy is vertebrae

Question 32

Characteristics of vertebrates

Answer 32

1. jointed dorsal column 2. anterior cranium (skull) with a large brain 3. well developed circulatory system with a ventral heart

Question 33

Agnathans

Answer 33

- hagfish and lamprey | - split off before evolution of jaws and mineralized skeleton

Question 34

Gnathostomes

Answer 34

have jaws and bones

Question 35

Hagfishes

Answer 35

- skeleton and cranium of cartilage - no jaws, but tooth-like structures, made of protein, used to rasp tissue from dead organisms - marine scavengers - secrete tons of slime

Question 36

Lampreys

Answer 36

- skeleton and cranium of cartiladge | - mostly parasites of fishes; attach and rasp at host tissue using tooth-like structures made of karatin

Question 37

true or false: | hemichordate is a chordate

Answer 37

false