BIO 152 EXAM 2 WITH CORRECT
ANSWERS 2025
What are the major characteristics of the Kingdom Animalia?
( What is an animal?) correct answers >> Common ancestor
(675 mya - 1 bya) similar to choanoflagellates
Multicellular ( chemoheterotrophic - eats other organic structures
for chemical energy)
Characteristic patterns of embryonic development
Most reproduce sexually
Tissues - groups of specialized cells that perform specific
functions (except for sponges):
digestion
movement
gas exchange
reproduction
impulse conduction
NO cell wall
Compare and contrast asymmetry, radial symmetry, and bilateral
symmetry? How do radial and bilateral symmetry relate to the
,classification of animals? correct answers >> Asymmetry: No
symmetry (sponges)
Radial Symmetry: arranged around a central axis. (sea urchin)
oral [mouth] and aboral [non-mouth side]
Bilateral Symmetry: has two symmetrical halves
Cephalization - concentration of well-developed sense organs at
one end (head) = directional movement
greater mobility
Animal development: what stages do most sexually reproducing
animals have in common? correct answers >> Zygote divides
3 times to form a multicellular, hollow blastula.
Blastula then undergoes gastrulation to form a gastrula with a
blastopore (opening to the outside).
From the gastrula either one of two groups forms: protostomes
(mouth first) or deuterostomes (anus first).
Explain what each of the three embryonic germ layers produces
in the adult animal: ectoderm, endoderm, and mesoderm.
correct answers >> Endoderm: Inner (digestive organs,
intestines, lungs, liver, pancreas...)
Mesoderm: Middle (skeleton, muscle, blood, heart, joints)
,Ectoderm: Outer (skin, nervous system, hair)
How many embryotic tissue (germ) layers do animals with radial
symmetry have? How many do bilateral symmetrical animals
have? correct answers >> Radial Symmetry = Diploblast (2
germ layers): Endoderm and Ectoderm
Bilateral Symmetry = Triploblast (3 germ layers): Endoderm,
Mesoderm, and Ectoderm
What are the major differences between the embryonic
development of protostomes and deuterostomes. Which animal
groups do these terms apply to? Which groups can give rise to
monozygotic twins? correct answers >> Protostomes:
Cleavage pattern of cells - spiral
Developmental fate of cells - determinate (unable to be
differentiated)
Fate of blastopore - mouth
Coelom origin - mesoderm
Deuterostomes:
Cleavage pattern of cells - radial
Developmental fate of cells - indeterminate (can form any cell
type)
Fate of blastopore - anus
Coelom origin - indirectly from archenteron (primitive body cavity)
, Only deuterostomes can give rise to monozygotic twins because
they have indeterminate cells that can form any cell type.
These terms only apply to bilateral symmetric animals because
they have the mesoderm. (Triploblast) Every animal phylum we
studied except for the Porifera and Cnidaria
Describe the 3 types of body cavities of animals. What are the
evolutionary advantages of a coelom? correct answers >> 1.
Acoelomate - no body cavity
2. Pseudocelomate - body cavity between mesoderm and
endoderm
3. Eucoelomate - body cavity entirely within the mesoderm
Advantages of coelom:
Development of complex organ systems (circulatory system to
flow nutrients and remove wastes)
Support/protection for organs
Development of longer digestive tract
How do HOX genes influence animal body plans? correct
answers >> They are developmental regulatory genes
Master Controls:
When and where to put things
switch other genes on and off
ANSWERS 2025
What are the major characteristics of the Kingdom Animalia?
( What is an animal?) correct answers >> Common ancestor
(675 mya - 1 bya) similar to choanoflagellates
Multicellular ( chemoheterotrophic - eats other organic structures
for chemical energy)
Characteristic patterns of embryonic development
Most reproduce sexually
Tissues - groups of specialized cells that perform specific
functions (except for sponges):
digestion
movement
gas exchange
reproduction
impulse conduction
NO cell wall
Compare and contrast asymmetry, radial symmetry, and bilateral
symmetry? How do radial and bilateral symmetry relate to the
,classification of animals? correct answers >> Asymmetry: No
symmetry (sponges)
Radial Symmetry: arranged around a central axis. (sea urchin)
oral [mouth] and aboral [non-mouth side]
Bilateral Symmetry: has two symmetrical halves
Cephalization - concentration of well-developed sense organs at
one end (head) = directional movement
greater mobility
Animal development: what stages do most sexually reproducing
animals have in common? correct answers >> Zygote divides
3 times to form a multicellular, hollow blastula.
Blastula then undergoes gastrulation to form a gastrula with a
blastopore (opening to the outside).
From the gastrula either one of two groups forms: protostomes
(mouth first) or deuterostomes (anus first).
Explain what each of the three embryonic germ layers produces
in the adult animal: ectoderm, endoderm, and mesoderm.
correct answers >> Endoderm: Inner (digestive organs,
intestines, lungs, liver, pancreas...)
Mesoderm: Middle (skeleton, muscle, blood, heart, joints)
,Ectoderm: Outer (skin, nervous system, hair)
How many embryotic tissue (germ) layers do animals with radial
symmetry have? How many do bilateral symmetrical animals
have? correct answers >> Radial Symmetry = Diploblast (2
germ layers): Endoderm and Ectoderm
Bilateral Symmetry = Triploblast (3 germ layers): Endoderm,
Mesoderm, and Ectoderm
What are the major differences between the embryonic
development of protostomes and deuterostomes. Which animal
groups do these terms apply to? Which groups can give rise to
monozygotic twins? correct answers >> Protostomes:
Cleavage pattern of cells - spiral
Developmental fate of cells - determinate (unable to be
differentiated)
Fate of blastopore - mouth
Coelom origin - mesoderm
Deuterostomes:
Cleavage pattern of cells - radial
Developmental fate of cells - indeterminate (can form any cell
type)
Fate of blastopore - anus
Coelom origin - indirectly from archenteron (primitive body cavity)
, Only deuterostomes can give rise to monozygotic twins because
they have indeterminate cells that can form any cell type.
These terms only apply to bilateral symmetric animals because
they have the mesoderm. (Triploblast) Every animal phylum we
studied except for the Porifera and Cnidaria
Describe the 3 types of body cavities of animals. What are the
evolutionary advantages of a coelom? correct answers >> 1.
Acoelomate - no body cavity
2. Pseudocelomate - body cavity between mesoderm and
endoderm
3. Eucoelomate - body cavity entirely within the mesoderm
Advantages of coelom:
Development of complex organ systems (circulatory system to
flow nutrients and remove wastes)
Support/protection for organs
Development of longer digestive tract
How do HOX genes influence animal body plans? correct
answers >> They are developmental regulatory genes
Master Controls:
When and where to put things
switch other genes on and off
