Lec 6/7 part A

Question 1

Protostomia taxonomic composition

Answer 1

Most invertebrates

Question 2

Deuterostomia taxonomic composition

Answer 2

Echinoderms, hemichordates and chordates

Question 3

Fate of blastopore of protostomia

Answer 3

Becomes mouth, second opening becomes anus

Question 4

Deuterostomia fate of blastopore

Answer 4

Becomes anus; second opening becomes mouth

Question 5

Diagnostic features

Answer 5

Characteristics that can identify members of a clade

Question 6

Synapomorphy

Answer 6

A derived feature shared by members of a taxonomic group. It is homologous and inherited from a common ancestor

Question 7

Homology

Answer 7

Homologous structures are ones that evolved from a common ancestral structure, though they may look different

Question 8

Similarity of topology example

Answer 8

Where the humerus is relative to other arm bones

Question 9

Similarity of detailed morphology example

Answer 9

Humeral head is convex

Question 10

Similarity of neural innervation example

Answer 10

Diaphragm innervated by the phrenic nerve

Question 11

Similarity of embryonic development example

Answer 11

The process of cell growth and differentiations to form the eyes

Question 12

Analogy definition

Answer 12

Analogous structures are ones that evolved from adaptations to similar environments

Question 13

Similar expressions to analogy

Answer 13

Convergent evolution and homoplastic

Question 14

Chordate characteristics

Answer 14

Notochord

Spinal chord

Pharyngeal slits

Post-anal tail

Endostyle

Question 15

Notochord

Answer 15

Still rod of soft tissue supporting the body axis

Transformed into vertebral centra in most vertebrates

Question 16

Spinal cord

Answer 16

Dorsal hollow nerve cord

Question 17

Pharyngeal slits

Answer 17

Ancestrally used for feeding, transformed into gill slits in fish, never fully develop in tetrapods

Question 18

Post anal tail

Answer 18

Tail that extends behind the anus

Question 19

Endostyle

Answer 19

Organ on the floor of the pharynx that secretes mucus and the hormone thyroxine; transformed into thyroid gland in vertebrates

Question 20

Ancestral feeding mode of chordates

Answer 20

Filter-feeding

Question 21

Filter feeding

Answer 21

Water is drawn in through the mouth and expelled through the pharyngeal slits, any food particles being filtered out and trapped in the mucus produced by the endostyle

Question 22

Cilia (tentacle like structures)

Answer 22

Drive movement of food and water in chordates

Question 23

Close relatives of vertebrates

Answer 23

Cephalochordata

Urochordata

Question 24

Cephalochordata

Answer 24

Small marine filter-feeding animals, somewhat fish like

Possess all give diagnostic features of chordates

Muscle blocks and fin propel swimming while notochord provides stiffness

Benthic on sea floor

Having distinct larvae and adult stages