week 9a

Question 1

What are Deuterostomes?

Answer 1

Animals in which the anus develops from the blastopore and the mouth from a second opening.

Question 2

Which groups are included in Deuterostomia?

Answer 2

Echinoderms and Chordates.

Question 3

What is a key characteristic of Phylum Echinodermata?

Answer 3

Modified radial symmetry (five parts) in adults.

Question 4

How do Echinoderms respire and excrete waste?

Answer 4

By diffusion; no excretory organs.

Question 5

What does autotomy refer to in Echinoderms?

Answer 5

The ability to intentionally detach body parts and regenerate them later.

Question 6

What are the main classes of Echinoderms?

Answer 6

• Asteroidea: sea stars
• Ophiuroidea: brittle stars
• Echinoidea: sea urchins, sand dollars
• Crinoidea: sea lilies and feather stars
• Holothuroidea: sea cucumbers.

Question 7

What is the body plan of the class Asteroidea?

Answer 7

Five arms; tube feet; predatory on bivalves and other echinoderms.

Question 8

What distinguishes the class Ophiuroidea?

Answer 8

Five long, slender arms; tube feet not used for locomotion.

Question 9

What are the characteristics of the class Echinoidea?

Answer 9

Spherical (sea urchins) or disc-shaped (sand dollars); no arms; tube feet and moveable spines.

Question 10

What defines the class Crinoidea?

Answer 10

Cup-shaped; often attached to substrate via stalk; arms feathery and used in filter feeding.

Question 11

What is the primary body shape of Holothuroidea?

Answer 11

Cucumber-shaped; no arms; spines absent.

Question 12

What are the key distinguishing innovations of Phylum Chordata?

Answer 12

• Notochord
• Dorsal hollow nerve cord
• Pharyngeal slits
• Postanal tail.

Question 13

What are the two subphyla of Chordata that include invertebrates?

Answer 13

Urochordates and Cephalochordates.

Question 14

What is the characteristic of Lancelets?

Answer 14

All marine filter feeders; gas exchange across body surface.

Question 15

What is the main feature of vertebrates?

Answer 15

Animals with a bony endoskeleton.

Question 16

What are the main characteristics of the clade Cyclostomata?

Answer 16

Jawless fishes, no appendages.

Question 17

What defines the clade Chondrichthyes?

Answer 17

Fishes with a cartilaginous skeleton; internal fertilization.

Question 18

What is the approximate number of species in the clade Actinopterygii?

Answer 18

31,830.

Question 19

What is a characteristic of Sarcopterygii?

Answer 19

Fishes with bony extensions projecting into pectoral and pelvic fins.

Question 20

What type of skeleton do vertebrates possess?

Answer 20

Endoskeleton of cartilage or bone.

Question 21

True or False: Echinoderms have a complex nervous system.

Answer 21

False.

Question 22

Fill in the blank: The water vascular system in Echinoderms is used for _______.

Answer 22

locomotion and feeding.

Question 23

What is the reproductive method of most Echinoderms?

Answer 23

Sexual reproduction with separate sexes and external fertilization.

Question 24

What is the significance of Hox genes in vertebrates?

Answer 24

They code for transcription factors that regulate development.

Question 25

What is a common feature of vertebrates concerning gene clusters?

Answer 25

Multiple clusters of Hox genes.

Question 26

What is the defining characteristic of fishes with ossified skeletons?

Answer 26

Single gill opening covered by operculum, fins supported by rays, swim bladder often present ## Footnote This group also has mucous glands in skin.

Question 27

What are the main characteristics of the clade Amphibia?

Answer 27

Adults able to live on land, freshwater needed for reproduction, development usually involving metamorphosis, adults with lungs and double blood circulation, moist skin, shell-less eggs ## Footnote Examples include frogs, toads, and salamanders.

Question 28

What is the approximate number of species in the clade Testudines?

Answer 28

346 ## Footnote Examples include turtles.

Question 29

What are the main characteristics of the clade Squamata?

Answer 29

Lower jaw not attached to skull, skin covered in scales ## Footnote Examples include lizards and snakes.

Question 30

What is the approximate number of species in the clade Crocodilia?

Answer 30

25 ## Footnote Examples include crocodiles and alligators.

Question 31

What are the main characteristics of the clade Aves?

Answer 31

Feathers, hollow bones, air sacs, reduced internal organs, endothermic, four-chambered heart ## Footnote Approximate number of species is 10,425.

Question 32

What are the defining features of mammals in the clade Mammalia?

Answer 32

Mammary glands, hair, specialized teeth, enlarged skull, external ears, endothermic, four-chambered heart, highly developed brains ## Footnote Approximate number of species is 5,500.

Question 33

What are the main characteristics of Cyclostomata?

Answer 33

Jawless, eel-like animals, lack eyes, jaws, fins, and vertebrae; skeleton comprised of notochord and cartilaginous skull ## Footnote Examples include hagfish and lampreys.

Question 34

What defines the class Chondrichthyes?

Answer 34

Skeleton composed of cartilage, includes sharks and rays ## Footnote Elasmobranchii includes skates, rays, and sharks.

Question 35

What is the difference between Actinopterygii and Sarcopterygii?

Answer 35

Actinopterygii are ray-finned fishes with fins supported by bony rays; Sarcopterygii are lobe-finned fishes ## Footnote Includes lungfishes and coelacanths.

Question 36

Fill in the blank: The swim bladder is often present in _______ fishes.

Answer 36

ossified

Question 37

True or False: All Cyclostomata have vertebrae.

Answer 37

False

Question 38

What is the primary characteristic of lobe-finned fishes?

Answer 38

Fins supported by fleshy lobes ## Footnote Examples include coelacanths and lungfishes.

Question 39

What is the significance of the notochord in Cyclostomata?

Answer 39

It serves as the primary skeletal support instead of vertebrae ## Footnote Essential for their structural integrity.