Bio 108 Lecture 22

Question 1

Craniata

cranium=

Answer 1

• Chordates with a head
• Largest animals that ever lived
  = skull

Question 2

5 Character states of Crainiates

Answer 2

1) Two or more clusters of Hox genes
2) Neural crest
3) Endoskeleton and pronounced cephalization
4) Modifications to circulatory system
5) Pharyngeal clefts function as gill slits

Question 3

Craniata Circulatory System

Answer 3

• Closed
• Heart with two chambers
• Haemoglobin in blood cells

Question 4

Jawless Craniates

Answer 4

• Two extant classes
• Called Agnathans
• Lack teeth, look like eels

Question 5

Myxini

Myxo =

Answer 5

• Hagfish
• Only craniates that lack vertebrae
• Cartilaginous cranium
• Pull off flesh in weird ways
• Tie body into knot and pull with mouth
• Protect themselves with slime
  = Myxo

Question 6

Vertebrata

Answer 6

• Have vertebral column

Question 7

Petromyzontida
petro =
myzo =

Answer 7

Lampreys
- Notochord surrounded by cartilaginous tube
- No jaws
- Parasites of fish
= rock
= suck

Question 8

Gnathostome Vertebrates

Gnath =

Answer 8

2 Pairs of fins evolved
- Four clusters of hox genes
Jaw
= jaw

Question 9

Chondrichthyes
chondro =
Ichthys =

Answer 9

• sharks
• endoskeleton made of cartilage
• cartilaginous fishes
• Cartilage not defining feature
• First cartilaginous and then ossified
  = cartilage
  = fish

Question 10

Features of Sharks

Answer 10

• Pectoral fin add lift
• Bouyancy by storing oil in liver
• Jagged scales
• Teeth continously replaced
• Can detect electrical fields and vibrations

Question 11

Shark Life Cycle

Answer 11

• Transfer sperm through copulation
• Internal fertilization
• Viviparous
• Protected in leathery egg case

Question 12

Chimeras

Answer 12

• Flat tooth plates for crushing shell prey

- Look like constructed by putting together bits of fishes