Chapter 2 exam 1 (lecture)

Question 1

What are the two major animal groups based on embryonic development?

Answer 1

Protostomes and Deuterostomes

Question 2

Protostomes:
-name meaning
-type of cleavage
-coelom type and where it develops from
-blastospore develops into __________

Answer 2

-“mouth first”
-spiral cleavage
-schizocoelom- coelom develops from splitting mesoderm
-blastospore develops into mouth

Question 3

examples of Protostomes

Answer 3

flat worms, snails, segmented worms etc

Question 4

Deuterostomes
-name meaning
-type of cleavage
-coelom type and where it develops from
-blastospore develops into __________

Answer 4

-second mouth
-radial aligned cleavage
-enterocoelom- originates from outpouching of gut
-anus

Question 5

examples of deuterostomes

Answer 5

us, subphylum hemichordata and Echinodermata (star fish and sea cucumbers)

Question 6

What are the three subphyla of phylum Chordata

Answer 6

-Cephalochordata
-Vertebrata
-Urochordata

Question 7

What kind of symmetry to chordates have? are they protostomes or deuterostomes?

Answer 7

-bilaterian, bilaterally symmetrical
-deuterostomes

Question 8

What are the 6 Synapomorphies of Chrodates?

Answer 8

1. notochord
   2.dorsal hollow nerve cord
2. Pharyngeal slits
3. post anal tail
4. endostyle
   6.myomeres

Question 9

T/F an organism must have all 6 of the chordate synapomorphies as a permanent adult characteristic to be considered a Chordate

Answer 9

False. may be a permanent adult structure or occur temporarily during development

Question 10

Where is the notochord in most vertebrates? what about mammals?

Answer 10

-replaced by vertebral column in most vertebrates
-persists as nucleus pulposus in mammals

Question 11

Why is the notochord essential for locomotion and stability?

Answer 11

the notochord has elastic properties allowing lateral flexion but prevents collapse of an organism when its muscles are contracted
-muscles work against notochord to bend
-longitudinal supporting rod

Question 12

what is the notochords core made up of?

Answer 12

-glycoproteins encased in a sheath of collagen fibers

Question 13

How does the notochord contribute to the development of the Dorsal Hollow nerve cord

Answer 13

-notochord induces neurulation which causes the ectoderm to become a neural plate
-the neural plate folds and the two lateral ends come together dorsally forming the dorsal hollow nerve cord

Question 14

What does the Dorsal Hollow nerve cord develop into in vertebrates?

Answer 14

Central nervous system:
-spinal cord and brain

Question 16

Where is the Dorsal hollow nerve cord situated in relation to the notochord

Answer 16

Dorsal is above the notochord

Question 17

Dorsal hollow nerve cord forms the Central nervous system via __________ induced by __________

Answer 17

-neurulation
-notochord

Question 18

in non-chordates, nerve cord is __________ placed and ________

Answer 18

-ventrally placed
-solid

Question 19

Pharyngeal slits definition

Answer 19

-series of small opening that pierce the pharynx

Question 20

describe how pharyngeal pouches in vertebrates are an example of an exaptation

Answer 20

initially used for functions like filter feeding, then became adapted for respiration/gas exchange in vertebrates by becoming vascularized