Lab 2 - intro to phylo trees and deuterostome taxa

Question 1

notochord

Answer 1

ORIGIN: mesoderm

LOCATION: dorsal to dig tract ventral to central nervous system / dorsal hollow nerve chord

FUNCTION: provides support for locomotion (lateral undulation) by engaging in lateral flexion, NOT axial compression

Question 2

post-anal tail

Answer 2

ORIGIN:

LOCATION: posterior to the anus

FUNCTION: lateral undulation to aid in locomotion

Question 3

pharyngeal slits

Answer 3

ORIGIN:

LOCATION: in pharynx, posterior to mouth

FUNCTION: openings in walls of pharynx that ???????

Question 4

dorsal hollow nerve chord

Answer 4

ORIGIN: invagination of ectoderm during neuralation

LOCATION: dorsal to the digestive tract

FUNCTION: forms the central nervous system

Question 5

cranium

Answer 5

ORIGIN: cartilage and bone from ????????

LOCATION: the head, brain area

FUNCTION: supports and protects the brain and other sensory structures

Question 6

tunic

Answer 6

ORIGIN: secreted by the epidermis, composed of tunicin protein and cellulose

LOCATION: surrounding the body

FUNCTION: protection

Question 7

myomeres

Answer 7

ORIGIN: myotome epimere mesoderm of somites

STRUCTURE: segmented blocks of skeletal muscle, separated by layers of connective tissue (myosepta)

LOCATION: part of body wall, arranged in series from anterior to posterior

FUNCTION:

Question 8

parsimonious

Answer 8

the simplest possible explanation/fewest number of evolutionary changes in this case

Question 9

echinoderm

Answer 9

marine organisms like sea stars, sea urchins, sea cucumbers, brittle stars, feather stars

larvae have bilateral symmetry, adults mostly have pentaradial

pharyngeal slits were secondarily lost

Question 10

hemichordate

Answer 10

three bod regions: proboscis, collar, trunk

Question 11

chordate

Answer 11

includes urochordata, cephalochordata, vertebrata

Question 12

cephalochordate

Answer 12

lancelets or amphioxus - small marine filter feed through pharyngeal slits

atrium

yes, endostyle

larvae and adults look similar, swim w post anal lat. undulations

Question 13

urochordate

Answer 13

tunicates

undergo significant metamorphosis, larvae swim w lateral und of post anal, as adults most are sessile filter feeders

pharynx and phar slits form filtering basket

cilia pump water into pharynx through buccal siphon

endostyle - yes!

Question 14

vertebrate

Answer 14

cartilagenous or bone vertebrae protecting dorsal hollow nerve chord

brain prot. by cranium

heart sep by valves

specialized sense organs

notochord as embryos, but in many lost during development

Question 15

ingroup

Answer 15

taxa that you are specifically analyzing ex deuterostome

Question 16

outgroup

Answer 16

a taxon closely related to but not part of the ingroup, maybe branch off one common ancestor earlier

Question 17

plesiomorphy

Answer 17

ancestral character state

Question 18

apomorphy

Answer 18

derived character state

Question 19

synapomorphy

Answer 19

a shared derived character state

Question 20

endostyle

Question 21

myxinoidea

Answer 21

no jaws

rudimentary eyes, one nostril

one posterior fin

sucking mouth, two rows of rasping projections on tongue

slimy, prod by specialized glands

Question 22

petromyzontida

Answer 22

no jaws, single nostril, cartilaginous skeleton, cranium

vertebra are tiny cartilagenous arches on dorsal surface of notochord

breath water through gills

larvae have an endostyle, but in metamorphosis this transforms into the thyroid gland

Question 23

gnathostomata

Answer 23

vertebrates with jaws

Question 24

chondrichthyes

Answer 24

inc. elasmobranchii (sharks and rays) and holocephali (chimeras or ratfish)

cartilagenous skeleton

5-6 external gill slits

spiracle to intake water while breathing

NO gas-filled swim bladder

Question 25

actinopterygii

Answer 25

bony fish

highly kinetic jaws

one pari of external gill openings, hills in opercular chamber protected by operculum

ray fins

Question 26

sarcopterygii

Answer 26

fleshy fins!

bony fish

Question 27

tetrapoda

Answer 27

muscular limbs w definied joints and digits

specialized cervical vertebra - atlas

Question 28

amphibia

Answer 28

eggs with no shalls or membranes, laid in water

adults normally have paired lungs

cutaneous gas exchange

one cervical vertebra - the atlas

Question 29

amniota

Answer 29

fish an amphibians

Question 30

sauropsida

Answer 30

birds and reptiles

Question 31

testudinata

Answer 31

turtles and their relatives

Question 32

lepidosauria

Answer 32

snake, legless lizards, lizards, tuatara

Question 33

archosauria

Answer 33

crocodilia and aves

Question 34

aves

Answer 34

birds

Question 35

crocodilia

Answer 35

crocs

Question 36

mammalia

Answer 36

synapsid skulls

one temporal fenestrae

hair, mammary glands, sebaceous oil glands, sweat glands

3 bones in middle ear

large brains

Question 37

teleostomi

Answer 37

have bony skeletons

most have internal inflatable gas bladder, in tetrapoda and sarcopterygii this acts as lungs, in actinopterygii this is a swim bladder

Question 38

pharynx

Question 39

homologous characters

Answer 39

shared characters inherited from a common ancestor

Question 40

deuterostome development

Answer 40

formation of the blastopore in the posterior reg. of the embryo (rather than anterior in protostomes