Diversity And Adaptations

Question 1

What are the 3 subphyla of chordates?

Answer 1

1. Urochordata
2. Cephalochordata
3. Vertebrata

Question 2

What is the name of the class for jawless fish? And what does it include?

Answer 2

Agnatha

Lampreys and hagfish

Question 3

What is the class for cartilaginous fish?

Answer 3

Chondrichthyes

Question 4

What are bony fish called?

Answer 4

Osteichthyes

Question 5

What are ray finned fish called?

Answer 5

Actinopterygii

Question 6

What are lobe finned fish called?

Answer 6

Sarcopterygii

Question 7

Name some common features of vertebrates

Answer 7

Vertebral column 
Brain at anterior end of nerve cord 
They’re craniates 
Vertebrae protects the spinal cord 
Closed loop circulatory system

Question 8

When did jawless fish originate and what are the 2 extant groups?

Answer 8

500mya

Lamprey and hagfish

Question 9

How many species of jawless fish are there?

Answer 9

90-100

Question 10

What things are jawless fish missing?

Answer 10

Jaw
Paired fins
Stomach or appendages

Question 11

When did bony fish first appear? And how many species are alive today?

Answer 11

410mya

25,000 species

Question 12

What percentage of bony fish/Osteichthyes are marine?

Answer 12

60%

Question 13

What is the largest class of vertebrates in existence today?

Answer 13

Osteichthyes- bony fish

Question 14

What is Osteichthyes divided into?

Answer 14

Actinopterygii and sarcopterygii

Question 15

What do all bony fish have?

Answer 15

Scales, gills and are cold blooded

Question 16

When did Chondrichthyes first appear? How many species are there?

Answer 16

420 mya

1,200 species
500 sharks, 600 skates and rays

Question 17

What are the skeletons of Chondrichthyes made out of?

Answer 17

Cartilage

Question 18

What don’t Chondrichthyes have for swimming? And what would happen if they stopped swimming?

Answer 18

A swim bladder

They would sink

Question 19

Is fertilisation internal or external in Chondrichthyes? And what is the usual development?

Answer 19

Internal

Ovoviparous- live birth

Question 20

What are the two subclasses of Chondrichthyes?

Answer 20

1. Elasmobranchii

2. Holocephali

Question 21

What are some of the characteristics of Chondrichthyes?

Answer 21

Jaws 
Paired fins
Denticles
Gills 
No gas bladder

Question 22

How many species of elasmobranchs can tolerate brackish or freshwater?

Answer 22

43 species

Question 23

How many kilometres have bull sharks been recorded from the mouth of the Amazon?

Answer 23

4,200km

Question 24

What is the name of flat bodied elasmobranchs?

Answer 24

Batoids

Skates and rays

Question 25

What are the differences in reproduction between skates and rays?

Answer 25

Rays are viviparous: live bearing Skates are oviparous: egg laying

Question 26

What are the 5 pelagic zones?

Answer 26

1. Epipelagic: surface to 200m 2. Mesopelagic: 200-1000m 3. Bathypelagic: 1000-4000m 4. Abyssopelagic: 4000m to sea floor 5. Hadopelagic: ocean trenches

Question 27

What fins are used for swimming?

Answer 27

Dorsal and caudal

Question 28

What is the ideal body shape?

Answer 28

4.5 fusiform

Question 29

What is the body shape number for sharks?

Answer 29

3-8

Question 30

What are the fins used for?

Answer 30

Stabilising, steering, lift and propulsion

Question 31

What is the role of the dorsal fins?

Answer 31

Anti-roll stabilising fins

Question 32

What are the uses of the pectoral fins?

Answer 32

Used for steering and help provide the shark with lift

Question 33

What does the causal fin provide when swimming?

Answer 33

Thrust

Question 34

What type of tail do most fish have?

Answer 34

Homocercal tail

Question 35

What type of tail do sharks usually have?

Answer 35

A heterocercal or epicercal tail

Question 36

What are shark scales called?

Answer 36

Dermal denticles

Question 37

What are dermal denticles similar to in humans?

Answer 37

Teeth

Question 38

How is the age of elasmobranchs estimated?

Answer 38

Counting growth rings on vertebra Counting growth rings on the spine in some species e.g spiny dogfish

Question 39

How do sharks generate dynamic lift?

Answer 39

By moving through the water using their outspread pectorals or by inclining their bodies at an angle of attack

Question 40

How do Chondrichthyes and bony fish generate static lift?

Answer 40

Bony fish: swimbladder Chondrichthyes: cartilage, lipids (squalene)= less dense than water

Question 41

Where do sharks store oil?

Answer 41

Liver and muscles

Question 42

How many pairs of gills do sharks have?

Answer 42

5-7

Question 43

What is the spiracle? And what’s its function?

Answer 43

Basically a first gill slit Provides oxygenated blood directly to the eye and brain through a separate blood vessel