Origin of Chordates and jaw

Question 1

The primary function of the notochord is
	A)	sensory.
	B)	digestive.
	C)	support.
	D)	respiration.

Answer 1

C) Support

Question 2

Cladistics shows that the chordates contain paraphyletic groupings such as

Answer 2

reptiles and birds.

Question 3

In terrestrial vertebrates, which structure did not arise from the pharyngeal pouches?

Answer 3

intervertebral discs

Question 4

Pharyngeal gill slits first evolved for
	A)	respiration.
	B)	filter feeding.
	C)	support of the buccal cavity.
	D)	production of glandular tissue.

Answer 4

B) Filter feeding

Question 5

One chordate characteristic found in adult ascidians is the
	A)	vertebral column.
	B)	pharyngeal slits.
	C)	dorsal hollow nerve cord.
	D)	postanal tail.

Answer 5

B) Pharyngeal slits

Question 6

An unusual chordate morphological feature of ascidians is that ……

Answer 6

Their blood travels in both directions

Question 7

Cephalochordates are similar to higher fish in that they possess a
	A)	mesonephric kidney.
	B)	two-chambered heart.
	C)	tripartite brain.
	D)	closed circulatory system.

Answer 7

D) Closed Circulatory system

Question 8

The primary support system in vertebrates is the
	A)	living exoskeleton.
	B)	living endoskeleton.
	C)	nonliving exoskeleton.
	D)	nonliving endoskeleton.

Answer 8

B) Living Endoskeleton

Question 9

The earliest ostracoderms could be characterized in this way:
	A)	heterostracans with paired fins.
	B)	acanthodians with jaws.
	C)	placoderms without jaws.
	D)	heterostracans without jaws.

Answer 9

C) Placoderms without jaws

Question 10

Of the early fish, which led to the extant fish of today?
	A)	heterostracans
	B)	placoderms
	C)	cephalochordates
	D)	acanthodians

Answer 10

D) Acanthodians

Question 11

Garstang introduced the theory of ________, which stated that the juvenile characteristics of the ascidian led to the vertebrates.

Answer 11

Paedomorphosis

Question 12

What is the evolutionary process in which larval or juvenile features of an ancestral organism are displaced to the adult forms of its descendants

Answer 12

Paedomorphosis

Question 13

The origin of the jaw in the gnathostomes is the
	A)	gill arch.
	B)	bones supporting the cranium.
	C)	notochord.
	D)	hyoid.

Answer 13

A) Gill arch

Question 14

It is relatively safe to say that your closest evolutionary relative is a(n)
	A)	echinoderm
	B)	insect.
	C)	earthworm.
	D)	nematode

Answer 14

A) Echinoderm

Question 15

How many germ layers do chordates have?

Answer 15

Three

Question 16

The system of the body that most clearly marks the advancement of the vertebrates is the ____________

Answer 16

Nervous system

Question 17

Although it may not be the ancestor that led to the chordates, the first chordate known from the fossil record is Pikaia. True or False

Answer 17

True

Question 18

The earliest chordate fossils come from the Cambrian, although vertebrate fossils are not seen until fossils from the Mesozoic are examined. True or False

Answer 18

False

Question 19

Predatory lifestyles in the gnathostomes were possible because of the development of _____

Answer 19

Jaws

Question 20

What was the primary life style of larvacean and thaliacean urochordates?

Answer 20

planktonic

Question 21

The most current hypotheses concerning the evolution of the chordates involve a link to a group of fossil echinoderms, the _______

Answer 21

Calcichordates.

Question 22

The larvaceans are the most common of the urochordates and are known as sea squirts. True or False

Answer 22

False

Question 23

The urochordates exhibit the four chordate characteristics in the most obvious form in the adult. True or False

Answer 23

False

Question 24

The larvae of the cephalochordate transform from a free-swimming form to a sessile adult. True or False

Answer 24

False

Question 25

What are some of the benefits of vertebrates having an endoskeleton

Answer 25

Allows for continuous growth without moulting. Efficient framework for muscle attachment.

Question 26

The chordate deuterostomes exhibit radial cleavage, an anus derived from the blastopore, and enterocoelous coelom formation. True or False

Answer 26

True

Question 27

The taxonomic terms reptile and agnatha are actually ______

Answer 27

Polyphyletic taxa.

Question 28

Taxonomic terms to describe you, a human being, would be _____, _____, _____, _____, _____, and _____

Answer 28

Chordata, Vertebrata, Craniata, Gnathostomata, Tetrapoda, and Amniota.

Question 29

Taxonomic terms to describe a trout would be ____, ____, ____, ____, ____, and ____

Answer 29

Chordata, Vertebrata, Craniata, Gnathostomata, Pisces, and Anamniota.

Question 30

The dorsal tubular nerve cord is formed by endodermal tissues during embryological development. True or False

Answer 30

False (Part of the ectoderm)

Question 31

The term postanal tail means that the tail extends beyond the anus. For example, in fish, the tail fin, and some musculature extend beyond the anal opening. True or False

Answer 31

True

Question 32

``` Zoologists consider ____ the closest living relative of vertebrates. A) hemichordates B) urochordates C) cephalochordates D) ostracoderms ```

Answer 32

C) Cephalochordates

Question 33

What is are the 5 characteristic of all chordates

Answer 33

Notochord - Dorsal nerve cord - Pharyngeal gill slits - Post anal tail - Endostyle (Thyroid)

Question 34

What are the features to a Notochord

Answer 34

Body support - length of body - Area for muscle attachment - Longitudinally stiff but flexible from side to side - Dorsal of the gut

Question 35

What are the features of a Dorsal nerve cord

Answer 35

Tubular - Dorsal side of notocord - anterior Cephalization

Question 36

What are the features of Pharyngeal gill slits

Answer 36

Perforations leading from the pharynx to outside - Paired on either side - Originally for filter feeding then developed into respiration/other structures

Question 37

What are the features of a Post anal tail

Answer 37

Part of skeletal support, muscles, and nervous system - Aids in locomotion/agility/balance.

Question 38

What are the features of a Endostyle (Thyroid)

Answer 38

Groove in the pharynx floor - Ciliated - Secretes mucus (Hormones in humans) - Moves food to the stomach - Lampreys have both

Question 39

Other 5 features of Chordates

Answer 39

Bilaterally symmetrical - Segmented muscles - Closed circulatory system with ventral heart - Pronounced cephilzation - Complete digestive system