Lab 13 Chordata

Question 1

Subphylum: Cephalochordata

Answer 1

Common Name: Lancelets

• pharyngeal basket and full bars
• benthic and filter feeders
• lie in the sand with their head above sand and filter feed

Question 2

Subphylum Urochordata

Answer 2

Tunicates

• common name: sea squirts
• pharyngeal basket and siphons
• they draw water through their incurrent siphon and food is filtered through the pharynx and digestive track and is then ejected through excurrent siphon

Question 3

Subphylum: Vertebrata

Answer 3

Vertebrates

Question 4

Superclass: Agnatha

Answer 4

Hagfish

• no jaws, teeth, paired fins
• have a cartilaginous skeleton
• detritivores

Lampreys
Same but parasitic

Question 5

Class: Chondrichthyes

Answer 5

Sharks, skates, rays, chimeras

• placoid scales (hard, rough, teeth like)
• cartilaginous skeleton
• exposed gills
• no swim bladder

Evolutionary trait: jaws with teeth and paired fins

Question 6

Class: Actinopterygii

Answer 6

Ray finned fishes

• skeleton made of bone
• Boney rays supporting fins
• operculum covering gills
• swim bladder
• dermal scales

Question 7

Class: Sarcopterygii

Answer 7

Lobe finned fishes

Evolutionary traits: lobe fins (precursors to limbs used on land)

Question 8

Class: Amphibia

Answer 8

Amphibians-frogs, toads, salamanders

Evolutionary: lungs and limbs

Question 9

Class: Reptilia

Answer 9

Reptiles-snakes, lizards, turtles, tortoises

Evolutionary traits: amniotic egg, hardened scales/ scutes

Question 10

Class: Aves

Answer 10

Birds

Evolutionary traits: feathers (modified scales), endothermy, wings, flight-Skelton became light weight and jbkf 1 kidney/gonad

Question 11

Class: Mammalia

Answer 11

Mammals- placentals, marsupials, monotremes

Evolutionary traits: mammary glands, fur or hair, sweat glands

Question 12

What traits/synapomorphies found in Chordata?

Answer 12

• Notochord
• Pharyngeal Gill slits
• dorsal hollow nerve cord
• post anal tail

Question 13

What traits do only vertebrates share?

Answer 13

• anterior skull enclosing brain
• rigid interior skeleton supported by vertebral column
• internal organs suspended in a coelom
• well developed circulatory system/ central heart

Question 14

What are the 3 groups of mammals and their traits?

Answer 14

1. monotremes: lay eggs, lack nipples
2. Marsupials(Metatherians): offspring born early in development and completes development in pouch
3. Placentals: complete development inside uterus with placental attachment to mom-gas exchange, nutrients, waste removal, mostly developed at birth