Bio Ch 29

Question 1

Chordates

Answer 1

euterostomes; don’t have an exoskeleton; have an internal skeleton made of bone and cartilage to which muscles are attached (allows freedom of movement and attainment of a larger body size than invertebrates)

Question 2

Notochord

Answer 2

dorsal supporting rod; located just below the nerve cord; majority of vertebrates have an embryonic one of these that is replaced by the vertebral column during embryonic development

Question 3

Dorsal tubular nerve cord

Answer 3

spinal cord, protected by vertebrae

Question 4

Gills

Answer 4

respiratory organs of aquatic vertebrates

Question 5

Cephalochordates

Answer 5

ex. Lancelets; marine chordates

Question 6

Urochordates

Answer 6

sea squirts; AKA tunicates because adults have a tunic (outer covering) that makes them look like thick-walled, squat sacs

Question 7

Gnathostomes

Answer 7

animals with jaws

Question 8

Tetrapods

Answer 8

terrestrial vertebrates with 4 limbs

Question 9

Amniotes

Answer 9

animals that exhibit an amniotic membrane

Question 10

Fishes

Answer 10

largest group of vertebrates (28K species)

Question 11

Ostracoderms

Answer 11

earliest fossils of Cambrian origin were these small, filter-feeding, jawless, finless fish

Question 12

Agnathans

Answer 12

jawless fishes; have a cartilaginous skeleton and persistent notochord; cylindrical, up to a meter long, have smooth, nonscaly skin

Question 13

Ectotherms

Answer 13

depend on the environment to regulate their temperature

Question 14

Fins

Answer 14

projections that are controlled by muscles

Question 15

Placoderms

Answer 15

extinct jawed fishes of the Devonian period; probably the ancestors of early sharks and bony fishes

Question 16

Cartilaginous fishes

Answer 16

Chondrichthyes; skeleton composed of cartilage instead of bone; 5-7 gill slits on both sides of the pharynx; lack the gill cover of bony fishes; many have openings to the gill chambers located behind the eyes (spiracles)

Question 17

Bony fishes

Answer 17

Osteichthyes; majority of living vertebrates (25K species)

Question 18

Ray-finned bony fishes

Answer 18

majority of fish species; fan-shaped fins supported by a thin, bony ray; most successful and diverse of all the vertebrates

Question 19

Swim bladder

Answer 19

gas-filled sac many bony fishes have into which they can secrete gases or from which they can absorb gases, altering its pressure

Question 20

Lobe-finned fishes

Answer 20

possess fleshy fins supported by bones

Question 21

Lungfishes

Answer 21

fish with lungs and gills for gas exchange

Question 22

Amphibians

Answer 22

vertebrates that live on both land in in water; typically tetrapods, smooth & nonscaly skin, lungs, double-loop circulatory pathway, sense organs, ectothermy, & aquatic reproduction

Question 23

Reptiles

Answer 23

very successful group of terrestrial animals consisting of more than 17K species, including birds; have paired limbs, skin, efficient breathing, efficient circulation, efficient excretion, ectothermy, well-adapted reproduction

Question 24

Amniotic egg

Answer 24

contains extraembryonic membranes, which protect the embryo, remove nitrogenous wastes, and provide the embryo with oxygen, food, and water

Question 25

Anapsid

Answer 25

skull with no openings behind the orbit (eye socket); ex. turtles

Question 26

Diapsid

Answer 26

having two openings in the skull behind the orbit (ex. reptiles other than turtles; birds)

Question 27

Synapsid

Answer 27

having one opening in the skull behind the orbit (ex. mammals)

Question 28

Dinosaurs

Answer 28

varied greatly in size and behavior; average size = chicken; some were the largest land animals ever to live

Question 29

Birds

Answer 29

share a common ancestor with crocodilians and have traits such as the presence of scales (feathers = modified scales), a tail with vertebrae, and clawed feet that show they are indeed reptiles

Question 30

Endotherms

Answer 30

use metabolic heat to maintain a constant internal temperature; property associated with efficient nervous, respiratory, and circulatory systems

Question 31

Mammals

Answer 31

include the largest animal ever to live (blue whale), the smallest animal (Kitti’s bat), and the fastest land animal (cheetah); distinguished by hair, mammary glands, skeleton, internal organs, and internal development

Question 32

Monotremes

Answer 32

egg-laying mammals that include only the duck-billed platypus and two species of echidna (spiny anteaters); term refers to the presence of a single urogenital opening (cloaca), which is a shared excretory & reproductive canal

Question 33

Marsupials

Answer 33

pouched mammals; ex. kangaroos, koalas, Tasmanian devils, wombats, sugar gliders, and opossums; have a true uterus

Question 34

Placental mammals

Answer 34

AKA eutherians; dominant group of mammals on Earth

Question 35

Placenta

Answer 35

very specialized organ for the exchange of substances between maternal blood and fetal blood