EXAM 1

Question 1

An era when the first shark-like fishes and ancestors of modern day species first appeared was __, which spanned from 450-245 million years ago

Answer 1

Paleozoic era

Question 2

Most recent era when most modern day species of sharks and their relatives appeared was the __, which began about 65 million years ago

Answer 2

Cenozoic era

Question 3

Symmoiiformes, Cladoselachiformes, and Eugeneodontiformes are examples of sharks that were common in the __ era

Answer 3

Paleozoic

Question 4

Superorders of sharks

Answer 4

Squalomorphii and Galeomorphii

Question 5

What is Taxonomy?

Answer 5

the science of classifying organisms

Question 6

What is phylogeny?

Answer 6

classification system that takes into consideration the evolutionary history of species

Question 7

Heliocoprion

Answer 7

this shark is known for its spiral tooth whorl

Question 8

What are fossil records of elasmobranchs based almost entirely on?

Answer 8

teeth

Question 9

The characteristics that are useful in shark classification as they vary among orders, families and sometimes species of sharks:

Answer 9

structure & number of vertebrae, design of eyelids, chondrocranium morphology

Question 10

A source of information used in phylogenetics - used to group sharks and their relatives into orders, families and genera is:
a. morphological features
b. physioloy
c. dna
d. all of the above

Answer 10

ALL OF THE ABOVE

Question 11

What structure found in sharks and their relatives are dervied from placoid scales?

Answer 11

teeth, fin spines, stinging spines, clasper spurs

Question 12

Ways in which sharks and their relatives are distinct physiologically from most bony fishes?

Answer 12

Reproductive structures, giving live birth, lacking swim bladder, gill slits, cartilaginous skeleton

Question 13

How do sharks reproduce?

Answer 13

Internal fertilization

Question 14

What is spawning

Answer 14

male and female gametes released near each other in the water

Question 15

Cladistics

Answer 15

a phylogenetic classification system that uses shared dervied characters and ancestry as the sole criterion for grouping taxa

Question 16

Cladogram

Answer 16

Diagram that shows the evolutionary relationships among a group of organisms

Question 17

What sources can potentially be used as a basis for determining phylogenetic relationships?

Answer 17

morphology, gene sequencing, specialized structures

Question 18

What are the mechanisms for evolution other than natural selection?

Answer 18

mutations, gene flow, genetic drift

Question 19

Give an example of an isolating mechanism that might result in speciation among Bonnethead sharks

Answer 19

sea level changing which created a geographical isolation between the sharks

Question 20

How many orders of modern day sharks are there?

Answer 20

nine

Question 21

What are the nine orders of modern day sharks?

Answer 21

Squatiniformes, Pristiophoriformes, Squaliformes, Hexanchiformes, Lamniformes, Orectolobiformes, Heterodontiformes, Carcharhiniformes, Echniorhinoformes

Question 22

What is convergent evolution?

Answer 22

occurs when similar structures from different species appear as adaptations to the same environment

Question 23

Example of convergent evolution in sharks

Answer 23

streamlined body style

Question 24

What two dominant groups of modern day fishes arrived on earth a little more than 400 million years ago?

Answer 24

Osteichthyes, Chondrichthyes

Question 25

What is the difference between Osteichthyes and Chondrichthyes

Answer 25

Osteichthyes are fish with skeletons of bone and, while chondrichthyes have a cartilaginous skeleton and include sharks and rays

Question 26

What class are sharks in

Answer 26

Chondrichthyes

Question 27

What subclass are sharks in

Answer 27

Elasmobranchii

Question 28

How is the evolutionary history of elasmobranchs related to mass extinctions?

Answer 28

Mass extinctions in the past two eras have led to the rise of present day elasmobranchs due to lack of competition in other niches

Question 29

What are the three eras in history of the Earth

Answer 29

Paleozoic, Mesozoic, Cenozoic

Question 30

Because of inverse relationship between force produced and rate of shortening, muscles of large animals shorten ___ and generate ___ force per contraction

Answer 30

SLOWLY, MORE

Question 31

An example of a tissue found in animals that is MORE dense than sea water

Answer 31

Skin

Question 32

What is the advantage in using neutral buoyancy?

Answer 32

Energy saving

Question 33

Which is NOT a species of shark included in the order Heterodontiformes? Horn shark Port Jackson shark Japanese bullhead shark Zebra shark

Answer 33

ZEBRA SHARK

Question 34

Body shape that has lowest drag coefficient is:

Answer 34

Streamlined, teardrop shape

Question 35

For most species of deep-sea sharks, their livers represent around __% of their body weight.

Answer 35

20%

Question 36

Sharks in the order Heterodontiformes are commonly known as:

Answer 36

Bullhead sharks

Question 37

The major buoyancy mechanism for deep-sea sharks is:

Answer 37

their liver

Question 38

A low density (0.86) hydrocarbon found in large quantities in the liver oil of many deep-sea sharks is:

Answer 38

Squalene

Question 39

The pectoral fins of sharks function to provide hydrodynamic lift in a similar manner as airplane wings provide aerodynamic lift. Both lifting surfaces generate lift due to ________ differences between the upper and lower fin/wing.

Answer 39

Pressure

Question 40

How many species of elasmobranchs are there?

Answer 40

~1100

Question 41

What is the common name of Heterodontid sharks

Answer 41

Bullhead shark

Question 42

Characteristics of Heterodontid sharks?

Answer 42

Big prominent brow ridge, spines on dorsal fin, pig-like snout

Question 43

How is the ability to move advantageous for animals such as elasmobranchs

Answer 43

Finding food, avoiding predators, finding a mate and producing young, remaining in a physiologically optimal environment.

Question 44

Describe the relationship between force produced and rate of shortening of muscles.

Answer 44

The faster that muscles are shortened, the lower the overall force produced; A slower rate of muscle contraction (shortening) yields greater overall force

Question 45

Explain why large animals such as many species of elasmobranchs expend relatively less energy to move a certain mass a certain distance.

Answer 45

Energy consumption per unit mass per unit distance for large animals is much lower than for small animals

Question 46

What factors influence the amount of drag experienced by an animal moving through water

Answer 46

Viscosity, body shape, surface area of body, speed of movement through water

Question 47

Explain how dermal denticles of elasmobranchs reduce drag.

Answer 47

Water flows across the dermal denticles to reduce turbulence and drag, turbulence resists movement and drag limits the speed of movement

Question 48

What structures on and around the tails of fast-moving fish reduce drag?

Answer 48

Finlets, scutes, keels and tubercles

Question 49

What lifting surfaces are found in sharks, how does their shape create lift

Answer 49

Head and body, Pectoral fins, Tail

Question 50

What is sustained swimming?

Answer 50

routine activity over long periods of time without muscular fatigue

Question 51

What is prolonged swimming?

Answer 51

Over shorter periods of time, muscle fatigue, these swimmers do NOT rest

Question 52

What is burst swimming?

Answer 52

VERY short periods of time, high velocity movement, usually used for prey capture or to escape from predators

Question 53

How do skates and rays generate forward propulsion?

Answer 53

Using pectoral fins, will undulate [little waves] or oscillate [flap like wings]

Question 54

What is anguilliform movement?

Answer 54

more head movement to propel forward, movement "like an eel"

Question 55

What is caraganiform movement?

Answer 55

majority of movement is concentrated in rear of body and the tail

Question 56

What is thunniform movement?

Answer 56

Head has the least rotation of all swimming forms, most movement coming from tail movement, very little overall body movement

Question 57

How do shallow water sharks maintain their position in the water column

Answer 57

Generate hyrodynamic lift with fins and head, constantly moving

Question 58

What major buoyancy mechanisms are common in deep water sharks?

Answer 58

Liver size, liver oil/lipids, muscle water

Question 59

What low density lipids are common in liver oil of deep-sea sharks?

Answer 59

Squalene and DAGE

Question 60

How does the density of Squalene and DAGE compare to that of triglycerides

Answer 60

Squalene and DAGE are significantly less dense than TG, especially squalene.

Question 61

How large are the livers of deep water sharks?

Answer 61

20-30% of their bodyweight

Question 62

What tissues and materials found in the bodies of elasmobranchs are more dense than surrounding seawater? less dense?

Answer 62

body tissues such as the skeleton, muscles, skin, and organs, are all more dense than seawater Lipids are less dense than seawater, and make up a significant portion of the liver