Bio 108 Lecture 22 Flashcards Preview

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Flashcards in Bio 108 Lecture 22 Deck (12):
1

Craniata
cranium=

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

2

5 Character states of Crainiates

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

3

Craniata Circulatory System

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

4

Jawless Craniates

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

5

Myxini
Myxo =

- 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

6

Vertebrata

- Have vertebral column

7

Petromyzontida
petro =
myzo =

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

8

Gnathostome Vertebrates
Gnath =

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

9

Chondrichthyes
chondro =
Ichthys =

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

10

Features of Sharks

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

11

Shark Life Cycle

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

12

Chimeras

- Flat tooth plates for crushing shell prey
- Look like constructed by putting together bits of fishes