Ben

Question 1

What is a chordate?

Answer 1

An organism that has pharyngeal slits, dorsal hollow nerve chord, post anal tail, and a notochord- at some point in the embryonic stage of the lifecycle.

Question 2

What is a vertebrate?

Answer 2

A chordate with a backbone- or precursors to vertebrae

Question 3

What are the characteristics of a vertebrate?

Answer 3

Possession of a backbone- or precursors to vertebrae, dermal bone- head appendages)- cephalisation - closed circulation and red blood cells.

Question 4

What is dermal bone?

Answer 4

Bone secreted onto the dermis of the organisms

Question 5

What is a craniate?

Answer 5

A chordate with a head.

Question 6

What is cephalisation?

Answer 6

Sensory organs focussed around the head- (comes into contact with the environment first)

Question 7

What is a fish?

Answer 7

A poikilothermic aquatic chordate

Question 8

What does poikilothermic mean?

Answer 8

Organisms where internal temperatures vary based on external environments- cannot regulate

Question 9

What does homeothermic mean?

Answer 9

An organism that can maintain homeostasis

Question 10

What are the characteristics of a fish?

Answer 10

Appendages developed as fins, tend to be bony, covered in scales and ectothermic- have swim bladder.

Question 11

What does ectothermic mean?

Answer 11

Any animal whose regulation of body temperature depends on external sources

Question 12

What are the 3 major subclasses of Chordata?

Answer 12

Urochordata (sea squirt)
Craniata (vertebrates and fish)
Cephalochordata (lancelets)

Question 13

How many superclasses are in Craniata?

Answer 13

8

Question 14

How many known living species of vertebrate are there?

Answer 14

55K

Question 15

Out of the 55k of living vertebrates, how many are tetrapods?

Answer 15

27K

Question 16

Out of the 27K of tetrapods, how many are marine?

Answer 16

0.5K

Question 17

Out of the 55k known species of vertebrates, how many are fish?

Answer 17

28K

Question 18

Out of the 28K fish, how many are marine?

Answer 18

16K

Question 19

Approximately how many species have been described?

Answer 19

1.5 million

Question 20

What is the estimated number of species that will be described on the planet?

Answer 20

5-9million

Question 21

Mineralised skeleton can be…?

Answer 21

Internal ( derived from cartilage precursors)

External (dermal bone)

Question 22

What did the development of bone allow?

Answer 22

Solid support for the attachment of muscles

Question 23

What was an advantage of developing bone?

Answer 23

Allowed fast and efficient locomotion (muscle attachment)

Question 24

What 2 things can bone be used for?

Answer 24

Storing chemicals (phosphates) for metabolism
Protection

Question 25

In the dawn of the Cambrian, why is the fossil record patchy?

Answer 25

Not much bone- cartilage was primary material so decomposed leaving no evidence

Question 26

What does paraphyletic mean?

Answer 26

A taxon that includes the most recent common ancestor, but not all of its descendants.

Question 27

What does mono/holophyletic mean?

Answer 27

A taxon that includes a group of organisms descended from a single ancestor

Question 28

What fish were dominant in the Silurian?

Answer 28

Ostracoderms