Bio final chapter 26,27,28,29

Question 1

Chordata

Answer 1

bilaterian animals in deuterostomia
bilteral symmetry
triploblastic- coelom
segmented bodies

Question 2

Chordata phylum

Answer 2

includes invertebrate
-cephalochordata
-urochordata
and Vertebrata 95%

Question 3

5 synopomorphies of chordata

Answer 3

notochord
dorsal hollow nere chord
pharyngeal slits
post anal tail
endostyle

Question 4

Notochord

Answer 4

stiff flexible rod
transfromed in vertebral column
between nerve chord and digestive tract
developed when organs in endoderm and from the mesoderm
provides structure

Question 5

dorsal hollow nerve chord

Answer 5

develops from plate of ectoderms that sinks and folds into neural tube
dorsal to notochord
general process of formation
-notochord and mesodermal cells secrete signal molecules
-ectodermal neural plate is formed
-neural tube develops into central nervous system
unique to chordates non chordates have ventral solid chord

Question 6

pharyngeal slits

Answer 6

pharynx is an anatomical region posterior to mouth
general process
-embryonic arch develops into pharynx
-pharyngeal cleft between arch develop into slits
tetropods slits only present in embryonic development
function:filter feeding gills for gas exchange in aquatic vertebrate

Question 7

Endostyle

Answer 7

organ on the floor of pharynx secretes mucous and iodine binding proteins
general process
-during development of slits longitudinal groove is formed on ventral aspect of pharynx
-endostyle groove cells differentiate into specialised glandular cells
vertebrate transformed into thyroid gland

Question 8

post anal tail

Answer 8

muscular tail posterior to the anus
length of digestive tract is shorter than full body length
non chordates it is the same length
post anal tail contains skeletal muscles
function-source of propulsion, balance and grip

Question 9

cephalochordata

Answer 9

lancelets sedentary filter feeding invertebrate
marine
feeding
wrinkle back into substrate
draw water and food particles through pharynx by ciliary
endostyle secretes mucous to capture food particles in pharynx
water exits through atripore
food and mucous pass through intestine
digested waste through anus

Question 10

Shared derived features of vertebrates

Answer 10

1. presence of vertebral column composed of mineralized (bones and cartilage) and unmineralized tissues (collagen fibres)
2. presence of a tripartite brain enclosed in skeletal brain case
   3.two or more sets of hox genes whole genome duplication happened at least twice in vertebrata basal chordates to earliest vertebrata and then jawless fish (agnathans) to jaw fish (gnathans)
   4.presence of true neural crest cells and ectodermal placodes
   5.fins or limbs paired fins-pectoral and pelvic unpaired-dorsal anal and tail (evolved first)
   6.complex respiratory and circulatory systems

Question 11

Tripartite brain vertebrate

Answer 11

head- pronounced cephalisation associated with development of endoskeleton composed of brain sensory organs and skeletal cranium
lower jaw excluded
brain- anterior expansion of the nerve cord specialized into part of the nervous system
three distinct parts
brain in early invertebrate is not completely enclosed by cranium, 10-12 cranial nerves

Question 12

Presence of true neural crest cells and ectodermal placodes

Answer 12

Neural crest cells-form vicinity of nerve cord in embryo and contribute to the formation of anatomical structures (jaw)
ectodermal placodes- tissue buds on the surface of embryonic head that sink inward contribute to forming sensory organs and nerves

Question 13

Complex respiratory and circulatory system vertebrate

Answer 13

supports higher metabolic rates
pharynx houses muscular rays=gas exchange and rackers=feeding
closed circulatory system with a heart-two chambers
cephalochordates no heart
urochordates heart with one chamber
Co2 and O2 transported by haemoglobin increase amount of gas transported
kidneys remove metabolic waste

Question 14

Cyclostomata

Answer 14

jawless fish paraphyletic group called agnatha
lampreys and hagfish
round mouths
lack paired fins

Question 15

lampreys-cyclostomata

Answer 15

poorly developed vertebrate
adults arched cartilaginous segments around notochord
well developed eye
absence of paired fin-dorsal and tail fins
filter feeders
adult lamprey
non feeding or parasitic feeding on blood of other fish

Question 16

hagfish- cyclostomata

Answer 16

deep in ocean floor
absence of paired fin
absence of image forming eye
three barbels as chemosensory organs
tongue with keratinised protrusion
90-100 slime glands -threads that uncoil to form network of intertangled strings
scavenger rip flesh off of carcasses

Question 17

what fossil makes up teeth

Answer 17

hydroxyapatite

Question 18

Shared dervived feature of gnathostomes

Answer 18

-jaw
-mineralized ossified skeleton
-paired appendages as limbs or fins
-enlarged forebrain of tripartite brain- enhanced smell and vision
-lateral line system
-4 sets of hox genes

Question 19

origin of jaws hypothesis

Answer 19

1.branchial arch hypotheses- in agnathan- mandibular arch are metameric segments of brachial arches
in gnathostomes- mandibular arch becomes both the upper and lower jaws connected by a joint premandibular jaw is incorporated. but brachial arch is not found in any vertebrate
2.ventilation breathing hypothesis- mandibular arch as brachial arch is incorporated with the mouth for pumping water into mouth for respiration not supported by fossil or developmental evidence
3. mandibular confinement- mandibular arch is constrained by surrounding tissues during embryonic development supporting evidence from comparative anatomy and embryonic development in zebra fish

Question 20

mineralized ossified skeleton

Answer 20

skeleton made up of bones and cartilage
2 types of bones
endochondral bones- develop from cartilage through ossification
dermal bones- develop from connected tissues through ossification

Question 21

teeth

Answer 21

mineralized structures anchored to jaw
composed of enamel and dentine
enamel is harder but more brittle than bones

Question 22

Origin of teeth hypothesis

Answer 22

1.Outside in hypothesis- odontode (tooth and toothlike tissues) originated as scales that migrated to mouth region evidence: teeth and placoid scales in sharks and their relatives have similar makeup, sharks and their relatives take on basal phylogenetic position
2. Inside out- odontode- orignated as teeth and migrated to skin, teeth developed from endoderm and scale from mesoderm

Question 23

lateral line system

Answer 23

sensory system in aquatic vertebrate
neuromast organs with hair cells to pick up chemical signals appear as pores originated from ectodermal placodes

Question 24

Diversity of fish phylogeny

Answer 24

chondrichthyes
osteichthyes- actinopterygii, sarcopterygii

Question 25

chondrichthyes

Answer 25

unossified cartilage mineralised teeth and placoid scales
physical protection and swimming

Question 26

actinopterygii and sarcopterygii

Answer 26

a-fins are supported by elongated bones connected to shoulders and pelvis triblastic fins
s- lobe fin, muscle positioned on skeletal elements of fin , single bone connected to pelvic girdle and pelvis

Question 27

elpistostegalia tiktaalik

Answer 27

transitional fossile with fish and tetrapod traits
fish traits- scales lobe fins rays instead of digits
tetrapod features- neck rib and limb anatomy

Question 28

fin to limb transition

Answer 28

sortapods
lateral line system
process on the ulna bone suggests well developed tricep muscles
reduction in number of digits

Question 29

challenges to living on terra firma

Answer 29

1. tetrapods enhance endoskeleton for stability and weight support
   2.modified closed circulatory system to work against gravity higher blood pressure valves in veins to prevent back flow
   3.aquatic environment and suction feeding-air cant faciliatate suction develop muscular tongue
2. land light is abundant- thinner eyes soft tissues to deform lens eyes and lubricate glands to protect eyes and lubricate

Question 30

shared derived features of tetrapods

Answer 30

neck
4 limbs
pelvis articulated with vertebral column and hindlimbs