Chapter 32

Question 1

Animal bodies are held together by structural proteins such as _______

Answer 1

collagen

Question 2

________ tissue and ________ tissue are unique, defining characteristics of animals

Answer 2

Nervous; muscle

Question 3

Tissues

Answer 3

groups of similar cells that act as a functional unit

Question 4

T/F: The diploid stage usually dominates the life cycle in animals

Answer 4

True

Question 5

Cleavage

Answer 5

rapid cell division that occurs in the zygote after a sperm fertilizes an egg

Question 6

blastula

Answer 6

a multicellular, hollow body created by cleavage

Question 7

the blastula undergoes __________, forming a ______ with different layers of embryonic tissues

Answer 7

gastrulation; gastrula

Question 8

Larva

Answer 8

a sexually immature organism in the early stages of a life cycle; morphologically distinct from the adult

Question 9

metamorphosis

Answer 9

the change that a larva undergoes to become a juvenile

Question 10

Juvenile

Answer 10

resembles an adult but is not yet sexually mature

Question 11

Most animals, and only animals, have ________

Answer 11

Hox genes

Question 12

Cadherins

Answer 12

a class of type-1 transmembrane proteins; they play important roles in cell adhesion

Question 13

Ediacaran Biota

Answer 13

early members of the animal fossil record which dates back to about 560 million years ago

Question 14

The Cambrian explosion

Answer 14

the event that marks the earliest fossil appearance of many major groups of living animals

Question 15

The Cambrian Explosion occurred _____ to ___________ years ago

Answer 15

535; 525 million

Question 16

Bilaterians

Answer 16

Most of the fossils from the Cambrian explosion

Question 17

Bilaterians have the traits:

Answer 17

• Bilaterally symmetric form
• Complete digestive tract
• One-way digestive system

Question 18

Coral reefs emerged during the ________ Era and became important marine ecological niches

Answer 18

Mesozoic

Question 19

mammals first emerged in the __________

Answer 19

Mesozoic Era

Question 20

the Mesozoic Era occurred _______________ years ago

Answer 20

251-65.5 Million

Question 21

the Cenozoic Era occurred __________ years ago

Answer 21

65.5 Million

Question 22

the Cenozoic Era followed the ____________ of both terrestrial and marine animals

Answer 22

mass extinctions

Question 23

body plan

Answer 23

a set of morphological and developmental traits by which zoologists sometimes categorize animals by

Question 24

Some animals have __________, with no…

Answer 24

radial symmetry; front and back, or left and right

Question 25

Bilateral symmetry

Answer 25

Two-sided symmetry

Question 26

Bilaterally symmetrical animals have...

Answer 26

a dorsal side, a ventral side, an anterior, and a posterior

Question 27

Dorsal

Answer 27

A top side

Question 28

Ventral

Answer 28

A bottom side

Question 29

Anterior

Answer 29

A front end

Question 30

Posterior

Answer 30

A back end

Question 31

Ectoderm

Answer 31

the germ layer covering the embryo's surface

Question 32

Endoderm

Answer 32

the innermost germ layer that lines the developing digestive tube, called the archenteron

Question 33

Diploblastic

Answer 33

animals that have ectoderm and endoderm

Question 34

Triploblastic

Answer 34

animals that also have an intervening mesoderm layer between the ectoderm and endoderm

Question 35

Most triploblastic animals possess a __________

Answer 35

body cavity

Question 36

Coelom

Answer 36

a true body cavity and is derived from the mesoderm

Question 37

Coelomates

Answer 37

animals that possess a true coelom

Question 38

Psuedocoelom

Answer 38

a body cavity that only has mesoderm on one side of the cavity

Question 39

pseudocoelomates

Answer 39

Triploblastic animals that possess a pseudocoelom

Question 40

acoelomates

Answer 40

Triploblastic animals that lack a body cavity

Question 41

In protostome development, cleavage is _______ and __________

Answer 41

spiral; determinate

Question 42

In deuterostome development, cleavage is _______ and __________

Answer 42

radial; indeterminate

Question 43

blastopore

Answer 43

forms during gastrulation and connects the archenteron to the exterior of the gastrula

Question 44

In protostome development, the blastopore becomes the _______

Answer 44

mouth

Question 45

In deuterostome development, the blastopore becomes the _______

Answer 45

anus