Ch. 32 Animals

Question 1

Define cleavage

Answer 1

zygote undergoes rapid cell division

Question 2

define asymmetry

Answer 2

refers to the lack of symmetry or balance in the arrangement of parts

Question 3

define radial symmetry

Answer 3

arranged around a single main axis that passes through the center of the animal

Question 4

define bilateral symmetry

Answer 4

arranged around two axes of orientation, the head-tail axis and the dorsal-ventral axis

Question 5

define diploblastic

Answer 5

2 germ layers

Question 6

define tripoblastic

Answer 6

3 germ layers: endoderm, ectoderm, and mesoderm. all bilateral animals

Question 7

define coelom

Answer 7

body cavity completely lined by tissue from mesoderm

Question 8

define hemocoel

Answer 8

body cavity incompletely lined with mesoderm and endoderm

Question 9

define compact body cavity

Answer 9

no body cavity animals are thing and flat bodies

Question 10

define determinate cleavage

Answer 10

is a type of embryonic development where the fate of each cell is determined early in the cleavage process

Question 11

define indeterminate cleavage

Answer 11

a type of embryonic development in deuterostomes in which each cell produced by early cleavage division retains the capacity to develop into a complete embryo

Question 12

define protosome

Answer 12

1st mouth, spiral, development of the mouth from the blastopore fate

Question 13

define deuterostome

Answer 13

2nd mouth, radial, development of anus from the blastopore fate

Question 14

define cephalization

Answer 14

concentration of sensory organs of anterior end

Question 15

define gastrovascular cavity

Answer 15

single opening: digestion and gas exchange like flatworm

Question 16

define alimentary canal

Answer 16

2 openings: mouth and anus all other bilateral

Question 17

What are the characteristics that distinguish the kingdom Animalia from others?

Answer 17

multicellularity, heterotrophy, lack of cell walls, diploid, sexually reproducing

Question 18

Which protists are considered to be the ancestors of fungi and animals?

Answer 18

opisthokonts

Question 19

What are some of the possible causes for the rapid diversification of animal body plans that
arose during the Cambrian explosion?

Answer 19

-new predator-prey relationships
- rise in atmospheric O2 favored animals with higher metabolic rates to survive
- Hox genes and microRNAs led to new body forms

Question 20

What is the distinction between the parazoa and the eumetazoa?

Answer 20

parazoa have no tissues and eumetazoa have tissues

Question 21

What is the relationship between an animal’s symmetry and its lifestyle?

Answer 21

Radial Symmetry: Suited for non-motile or drifting lifestyles.
Bilateral Symmetry: Suited for active movement and complex interactions with the environment.

Question 22

What do bilaterally symmetric animals have that radially symmetric animals generally lack?

Answer 22

radially symmetric lacks a left or right side

Question 23

What are the germ layers found in a diploblastic animal?

Answer 23

Ectoderm and endoderm

Question 24

What are the germ layers found in a tripbloblastic animal?

Answer 24

extoderm, endoderm, mesoderm

Question 25

What are triploblastic animals without a cavity between the gut and outer body wall called?

Answer 25

Compact body cavity

Question 26

What distinguishes a true coelom from a hemocoelom?

Answer 26

true Coelom: Fully mesoderm-lined, supports complex organ movement. Hemocoel: Mesoderm and endoderm-lined, supports nutrient transport in an open system.

Question 27

List several functions of a body cavity.

Answer 27

cushions organs, structural support, organ movement, internal transport

Question 28

Know the stages and characteristics of protostomal development.

Answer 28

Cleavage: spiral and determinate Coelom formation: solid masses of mesoderm split and form coelom Blastropore fate: mouth develops

Question 29

Know the stages and characteristics of deuterostomal development.

Answer 29

cleavage: radial and indeterminate Coelom formation: folds of archenteron form coelom Blastropore fate: anus develops

Question 30

order of eras

Answer 30

Neoproterozoic, Paleozoic, Mezozoic, and Cenzoic