BIO 212 quiz 5 Questions and Answers Fully Solved Latest Version 2025-2026
radial symmetry - Answers (dividedintomanyequalparts)is uncommon and best suited to sessile
or planktonic existenceallows animal to meet environment equally well on all sides
bilateral symmetry - Answers (divided into two halves) These animals have sensory organs and
nervous tissue concentrated in their head (cephalization) and are adapted to an active lifestyle
cephalization - Answers sensory organs and nervous tissue concentrated in their head
coelomate - Answers Most triploblastic animals that have mesodermic body cavity
pseudocoelomate - Answers three layers (endo, mess, ectoderm) - animals that have body
cavity with both mesodermic and endodermic tissue
acoelomate - Answers do not have a body cavity
deuterostome - Answers "two mouths"
protostome - Answers bilateral symmetry, three layers (mesoderm)
What type of lifestyle would favor radial symmetry and what type of lifestyle would favor
bilateral symmetry? - Answers radial symmetry best suited to sessile or planktonic existence
allows animal to meet environment equally well on all side. bilateral benefits by being able to
adapt to an active lifestyle.
What is the difference between diploblastic and triploblastic embryonic development - Answers
Diploblastic has two embryonic (or "germ") layers (endo-internal organs, ecto-external/skin
nervous system). Triploblastic includes mesodermic (a third layer) which includes body cavity
and muscles.
What types of tissues arise from ectoderm, mesoderm, and endoderm in triploblastic organisms?
- Answers ectoderm- outer covering and nervous system
mesoderm- body cavity and muscles
endoderm- internal organs
What are the advantages of having a body cavity? - Answers allows external body wall and
internal organs
to move independently, cushions internal organs, can act as a "skeleton" against which muscles
work
Describe the difference between protostome and deuterostome development, and identify
which of these modes of development is most common among animals. - Answers Protosomes
develop with spiral arrangement of embryonic cells that are determinate (their fate is fixed).
, Governed by a twisting of the mitotic spindle within the cell after each cell division.
Planesofcellsdivisionarediagonalto the vertical axis of the embryo.
Smallercellscenteredovergrooves between larger, underlying cells. Deuterostome develop with
radial (parallel) arrangement of embryonic cells that remain indeterminate for longer time. Does
not require twisting of mitotic spindle. Cellscanbe packed with more compounds (such as yolk
proteins) to nourish embryo. ***Most are spiral arrangment****
What are the advantages of deuterostome development? - Answers Deuterostome cell
development allows for embryonic cells to retain capacity to develop into a complete embryo.
What are the defining characteristics of lophotrochozoans? And ecdysozoans? - Answers
lophotrochozoans have lophophores (crown of ciliated tentacles) OR trochophore larva.
Ecdysozoans are animals that secrete exoskeletons.
nematocysts - Answers a specialized cell in the tentacles of a jellyfish or other coelenterate,
containing a barbed or venomous coiled thread that can be projected in self-defense or to
capture prey.
polyp - Answers asexual (jelly fish shape)
medusa - Answers sexual (barnacle shape)
gastrovascular cavity - Answers functions in both digestion and distribution of nutrients that has
a single opening
metazoan - Answers animals
eumetazoan - Answers all major animal groups
alimentary canal - Answers (digestive tube with mouth and anus) allows for more complete
digestion of food
parthenogenesis - Answers females that produce more females from unfertilized eggs (type of
asexual reproduction)
torsion - Answers twisting visceral mass
chaetae - Answers bristles made by chitin
Describe the lifecycle of a hydrozoan. How is this different from that of plants? - Answers
reproductive stage --> egg --> planula larva --> polyp budding new polyps --> polyp buddy
euphryas --> euphyras young medusa --> adult
Do cnidarians utilize sexual or asexual reproduction? - Answers polyps are asexual and
medusas are sexual
How do cnidarians accomplish movement? - Answers Medusas move by pinching their
radial symmetry - Answers (dividedintomanyequalparts)is uncommon and best suited to sessile
or planktonic existenceallows animal to meet environment equally well on all sides
bilateral symmetry - Answers (divided into two halves) These animals have sensory organs and
nervous tissue concentrated in their head (cephalization) and are adapted to an active lifestyle
cephalization - Answers sensory organs and nervous tissue concentrated in their head
coelomate - Answers Most triploblastic animals that have mesodermic body cavity
pseudocoelomate - Answers three layers (endo, mess, ectoderm) - animals that have body
cavity with both mesodermic and endodermic tissue
acoelomate - Answers do not have a body cavity
deuterostome - Answers "two mouths"
protostome - Answers bilateral symmetry, three layers (mesoderm)
What type of lifestyle would favor radial symmetry and what type of lifestyle would favor
bilateral symmetry? - Answers radial symmetry best suited to sessile or planktonic existence
allows animal to meet environment equally well on all side. bilateral benefits by being able to
adapt to an active lifestyle.
What is the difference between diploblastic and triploblastic embryonic development - Answers
Diploblastic has two embryonic (or "germ") layers (endo-internal organs, ecto-external/skin
nervous system). Triploblastic includes mesodermic (a third layer) which includes body cavity
and muscles.
What types of tissues arise from ectoderm, mesoderm, and endoderm in triploblastic organisms?
- Answers ectoderm- outer covering and nervous system
mesoderm- body cavity and muscles
endoderm- internal organs
What are the advantages of having a body cavity? - Answers allows external body wall and
internal organs
to move independently, cushions internal organs, can act as a "skeleton" against which muscles
work
Describe the difference between protostome and deuterostome development, and identify
which of these modes of development is most common among animals. - Answers Protosomes
develop with spiral arrangement of embryonic cells that are determinate (their fate is fixed).
, Governed by a twisting of the mitotic spindle within the cell after each cell division.
Planesofcellsdivisionarediagonalto the vertical axis of the embryo.
Smallercellscenteredovergrooves between larger, underlying cells. Deuterostome develop with
radial (parallel) arrangement of embryonic cells that remain indeterminate for longer time. Does
not require twisting of mitotic spindle. Cellscanbe packed with more compounds (such as yolk
proteins) to nourish embryo. ***Most are spiral arrangment****
What are the advantages of deuterostome development? - Answers Deuterostome cell
development allows for embryonic cells to retain capacity to develop into a complete embryo.
What are the defining characteristics of lophotrochozoans? And ecdysozoans? - Answers
lophotrochozoans have lophophores (crown of ciliated tentacles) OR trochophore larva.
Ecdysozoans are animals that secrete exoskeletons.
nematocysts - Answers a specialized cell in the tentacles of a jellyfish or other coelenterate,
containing a barbed or venomous coiled thread that can be projected in self-defense or to
capture prey.
polyp - Answers asexual (jelly fish shape)
medusa - Answers sexual (barnacle shape)
gastrovascular cavity - Answers functions in both digestion and distribution of nutrients that has
a single opening
metazoan - Answers animals
eumetazoan - Answers all major animal groups
alimentary canal - Answers (digestive tube with mouth and anus) allows for more complete
digestion of food
parthenogenesis - Answers females that produce more females from unfertilized eggs (type of
asexual reproduction)
torsion - Answers twisting visceral mass
chaetae - Answers bristles made by chitin
Describe the lifecycle of a hydrozoan. How is this different from that of plants? - Answers
reproductive stage --> egg --> planula larva --> polyp budding new polyps --> polyp buddy
euphryas --> euphyras young medusa --> adult
Do cnidarians utilize sexual or asexual reproduction? - Answers polyps are asexual and
medusas are sexual
How do cnidarians accomplish movement? - Answers Medusas move by pinching their
