ch 11 phylum chordata

Question 1

4 major anatomical characteristics of chordates

Answer 1

spinal cord, notochord, pharyngeal slits, post anal tail

Question 2

three classes studied in subphylum vertebrata

Answer 2

angatha, chondrichthyes, osteichthyes

Question 3

class agnatha

Answer 3

jawless fish

Question 4

class chondrichthyes

Answer 4

sharks and rays

Question 5

class osteichthyes

Answer 5

bony fishes

Question 6

what characteristics do all vertebrates have

Answer 6

nerve cord, central nervous system, complete digestive system, closed circulatory system, endoskeleton

Question 7

physical characteristics of jawless fishes

Answer 7

no jaws, body is cylindrical, no paired fins or scales, lack true vertebral column, cartilaginous skeleton

Question 8

characteristics of hagfish

Answer 8

feed on dead or dying fish, exclusively marine, no vertebrae, produce large amounts of mucus

Question 9

characteristics of lampreys

Answer 9

parasitic, primarily freshwater, have vertebrae

Question 10

what are the advancements seen in classes chondrichthyes and osteichthyes

Answer 10

-highly efficient gills
-scales cover body
-paired fins
-wide variety of jaw and feeding types
-lateral line and sensory organs
-streamlined body

Question 11

examples of cartilaginous fishes

Answer 11

sharks, skates, rays, chimeras

Question 12

osmoconformer

Answer 12

can regulate internal salinity to match salinity of surroundings

Question 13

physical characteristics of cartilaginous fishes

Answer 13

skeletons made of cartilage, placoid scales, claspers, reproduction

Question 14

characteristics of sharks

Answer 14

fusiform, spindle shaped bodies

Question 15

caudal fin

Answer 15

tail fin

Question 16

pectoral fin

Answer 16

steering fins

Question 17

dorsal fins

Answer 17

fin on the back

Question 18

shark adaptations to the marine world

Answer 18

countershading (ventral side is lighter than the dorsal side), osmoconformers (high concentration of salts and urea in blood), gills absorb oxygen from water

Question 19

shark life history traits

Answer 19

-slow growing
-long live
-mature late in life have long gestation periods
-small number of young
-wait a long time to reproduce again

Question 20

threats to shark populations

Answer 20

shark finning; potential increases in diseased, unfit, and unhealthy prey individuals

Question 21

physical characteristics of skates and rays

Answer 21

-have dorso-ventrally flattened bodies
-5 pairs of gill slits on ventral side of body
-demersal (live on bottom)
-pectoral fins are greatly extended and resemble wings

Question 22

differences between skates and rays

Answer 22

-skates have 2 dorsal fins; rays have no dorsal fins
-skates have a muscular tail; rays have a whip-like tail usually with a prominent stinger

Question 23

characteristics of chimeras (ratfishes)

Answer 23

• approximately 30 species
  -one pair of gill slits, covered by flap of skin
  -demersal (bottom dwelling)
  -have long, rat-like tail