BISC 120 FINAL EXAM
Characteristics of Animals - Answer- 1. Heterotrophic
2. Multicellular
3. Tissues that develop from embryonic layers
Tissues - Answer- Groups of similar cells that act as a functional unit
Cleavage - Answer- A succession of mitotic cell divisions without cell growth
between the divisions
Blastulae - Answer- Multicellular hollow ball
Gastrulation - Answer- A process in which one end of the embryo folds inward,
expands
Gastrula - Answer- Developmental stage at which embryonic tissues are
differentiated
Animal Evolution Timeline - Answer- -Proterozoic Eon (1 billion - 542 million years
ago)
-Ediacaran Period (~560 mya)
-Paleozoic Era (541-251 mya)
-Cambrian Period (~525 mya)
-Mesozoic Era (251-65.5 mya)
-Cenozoic Era (65.5 mya - present)
Ediacaran Period - Answer- ~560 MYA
-First generally accepted macroscopic fossils of animals date from around 560 MYA
-Soft-bodied multicellular eukaryotes "Ediacaran biota"
Cambrian Period - Answer- ~525 MYA
-Oldest fossils of about half of all extant animal phyla (e.g. arthropods, chordates,
echinoderms)
-This is where we first see animals that are ancestors to what we see today!
-Cambrian is when we start to see predator prey relationships established
throughout the planet
-Scales, outer surface develop, arms race develop (if one develops scales, the other
will develop teeth to be able to crack the scales, and so forth)
Paleozoic Era - Answer- -420 mya: arthropods first terrestrial animals
-365 mya: vertebrates colonize land
Mesozoic Era - Answer- -Age of dinosaurs
-First Mammals
Cenozoic Era - Answer- -Mass extinction of many animals
-Success of large mammals
, Radial Symmetry - Answer- Any imaginary slice through the central axis divides the
animal into mirror images
Bilateral Symmetry - Answer- Only one imaginary cut divides the animal into mirror-
image halves
Ectoderm - Answer- -Germ layer covering the surface of the embryo
-Gives rise to the outer covering of the animal and in some phyla, the central
nervous system
Endoderm - Answer- -The innermost germ layer, lining the archenteron
-Gives rise to the lining of the digestive tract (or cavity)
Mesoderm - Answer- Forms muscles and other internal organs
Diploblastic - Answer- Only ectoderm and endoderm
Triploblastic - Answer- Ectoderm, endoderm and mesoderm
Coelom - Answer- A fluid- or air-filled space located between the digestive tract and
the outer body wall
Coelomate - Answer- An animal that possesses a true coelom (a body cavity lined by
tissue completely derived from mesoderm
Pseudocoelomate - Answer- An animal whose body cavity is lined by tissue derived
from mesoderm and endoderm
Acoelomate - Answer- A solid-bodied animal lacking a cavity between the gut and
outer body wall
Protostome - Answer- Cleavage: 8 cell stage, spiral and determinate
Coelom Formation: Solid masses of mesoderm split and form coelom
Fate of the Blastopore: Mouth develops from blastopore
Deuterostome - Answer- Cleavage: 8 cell stage, radial and indeterminate
Coelom Formation: Folds of archenteron form coelom
Fate of the Blastopore: Anus develops from blastopore
Porifera - Answer- No symmetry
Filter feeders
Sessile (don't move)
Hermaphroditic
Lack true tissue
Collar cells resemble choanoflagellates
Basal animals
Ctenophora - Answer- Radial symmetry
Diploblastic
Characteristics of Animals - Answer- 1. Heterotrophic
2. Multicellular
3. Tissues that develop from embryonic layers
Tissues - Answer- Groups of similar cells that act as a functional unit
Cleavage - Answer- A succession of mitotic cell divisions without cell growth
between the divisions
Blastulae - Answer- Multicellular hollow ball
Gastrulation - Answer- A process in which one end of the embryo folds inward,
expands
Gastrula - Answer- Developmental stage at which embryonic tissues are
differentiated
Animal Evolution Timeline - Answer- -Proterozoic Eon (1 billion - 542 million years
ago)
-Ediacaran Period (~560 mya)
-Paleozoic Era (541-251 mya)
-Cambrian Period (~525 mya)
-Mesozoic Era (251-65.5 mya)
-Cenozoic Era (65.5 mya - present)
Ediacaran Period - Answer- ~560 MYA
-First generally accepted macroscopic fossils of animals date from around 560 MYA
-Soft-bodied multicellular eukaryotes "Ediacaran biota"
Cambrian Period - Answer- ~525 MYA
-Oldest fossils of about half of all extant animal phyla (e.g. arthropods, chordates,
echinoderms)
-This is where we first see animals that are ancestors to what we see today!
-Cambrian is when we start to see predator prey relationships established
throughout the planet
-Scales, outer surface develop, arms race develop (if one develops scales, the other
will develop teeth to be able to crack the scales, and so forth)
Paleozoic Era - Answer- -420 mya: arthropods first terrestrial animals
-365 mya: vertebrates colonize land
Mesozoic Era - Answer- -Age of dinosaurs
-First Mammals
Cenozoic Era - Answer- -Mass extinction of many animals
-Success of large mammals
, Radial Symmetry - Answer- Any imaginary slice through the central axis divides the
animal into mirror images
Bilateral Symmetry - Answer- Only one imaginary cut divides the animal into mirror-
image halves
Ectoderm - Answer- -Germ layer covering the surface of the embryo
-Gives rise to the outer covering of the animal and in some phyla, the central
nervous system
Endoderm - Answer- -The innermost germ layer, lining the archenteron
-Gives rise to the lining of the digestive tract (or cavity)
Mesoderm - Answer- Forms muscles and other internal organs
Diploblastic - Answer- Only ectoderm and endoderm
Triploblastic - Answer- Ectoderm, endoderm and mesoderm
Coelom - Answer- A fluid- or air-filled space located between the digestive tract and
the outer body wall
Coelomate - Answer- An animal that possesses a true coelom (a body cavity lined by
tissue completely derived from mesoderm
Pseudocoelomate - Answer- An animal whose body cavity is lined by tissue derived
from mesoderm and endoderm
Acoelomate - Answer- A solid-bodied animal lacking a cavity between the gut and
outer body wall
Protostome - Answer- Cleavage: 8 cell stage, spiral and determinate
Coelom Formation: Solid masses of mesoderm split and form coelom
Fate of the Blastopore: Mouth develops from blastopore
Deuterostome - Answer- Cleavage: 8 cell stage, radial and indeterminate
Coelom Formation: Folds of archenteron form coelom
Fate of the Blastopore: Anus develops from blastopore
Porifera - Answer- No symmetry
Filter feeders
Sessile (don't move)
Hermaphroditic
Lack true tissue
Collar cells resemble choanoflagellates
Basal animals
Ctenophora - Answer- Radial symmetry
Diploblastic
