Zoology Exam 2 Questions with
Complete Answers
chitin - Answer-A structural polysaccharide, consisting of amino sugar monomers,
found in many fungal cell walls and in the exoskeletons of all arthropods.
chiton - Answer-primitive elongated bilaterally symmetrical marine mollusk having a
mantle covered with eight calcareous plates
choanoblasts - Answer-One of several cellular elements within the syncytial tissue of
a hexactinellid sponge; bear flagellated extensions called collar bodies.
choanocytes - Answer-flagellated collar cells, generate a water current through the
sponge and ingest suspended food
chorion - Answer-outermost layer of the two membranes surrounding the embryo; it
forms the fetal part of the placenta
cilia - Answer-short structures projecting from a cell and containing bundles of
microtubules that move a cell through its surroundings or move fluid over the cell's
surface
circumenteric ring - Answer-part of a pseudocoelomate nervous system
clade - Answer-a group of biological taxa or species that share features inherited
from a common ancestor
cnidocyte - Answer-A specialized cell unique to the phylum Cnidaria; contains a
capsule-like organelle housing a coiled thread that, when discharged, explodes
outward and functions in prey capture or defense.
coelom - Answer-fluid-filled body cavity lined with mesoderm
collagen - Answer-a fibrous scleroprotein in bone and cartilage and tendon and other
connective tissue
collenocytes - Answer-A type of cell in sponges that is star-shaped and apparently
contractile.
colonial flagellate hypothesis - Answer-1. Metazoans from colonial flagellates
2. Molecular data (RNA) agree
3. Metazoans - related to fungi &
choanoflagellates
4. Opisthokonta (clade)
,commensalism - Answer-the relation between two different kinds of organisms when
one receives benefits from the other without damaging it
complete digestive system - Answer-animal has mouth and anus; food travels one
way
conispiral - Answer-more advanced kind of Gastropod shell where the right kidney,
auricle and kidney are lost to allow the Gastropod to completely withdraw into the
cell.
corona - Answer-head or upper end of a structure; ciliated disk on anterior end of
rotifers
crystalline style - Answer-Class Bivalvia; gelatinous rod that projects into the
stomach; the rotating of the style frees digestive enzymes and rolls the food mass
ctenidia - Answer-Comblike structures, especially gills of molluscs; also applied to
comb plates of ctenophora
cuticle - Answer-hard outer covering or case of certain organisms such as
arthropods and turtles
cysticeri - Answer-A type of juvenile tapeworm composed of a solid-bodied cyst
containing an invaginated scolex; contracts with cysticercus
cytokinesis - Answer-organic process consisting of the division of the cytoplasm of a
cell following karyokinesis bringing about the separation into two daughter cells
determinate cleavage - Answer-A type of embryonic development in protostomes
that rigidly casts the developmental fate of each embryonic cell very early.
deuterostome - Answer-animal whose anus is formed from the blastopore of a
blastula
dioecious - Answer-having male and female reproductive organs in separate plants
or animals
diploid - Answer-(genetics) an organism or cell having two sets of chromosomes or
twice the haploid number
discoidal cleavage - Answer-In an early embryo, cell division occurs within a small
disc of cytoplasm atop a large mass of yolk.
ectoderm - Answer-the outer germ layer that develops into skin and nervous tissue
endoderm - Answer-the inner germ layer that develops into the lining of the digestive
and respiratory systems
, enterocoelous - Answer-The type of development found in deuterostomes. The
coelomic cavities form when mesoderm buds from the wall of the archenteron and
hollows out.
ephyra - Answer-Tiny medusae that comes off the polyps in sexual reproduction
epitheliomuscular cells - Answer-form most of the epidermis and serve both for
contraction and for muscular contraction. Bases of these are myofibrils, which when
contracted shorten the body or tentacles.
epizooites - Answer-Rotiferians which live on other animals but are not parasitic
eutely - Answer-Development in which all adults have the same, fixed number of
cells (rotifers, nematodes, tardigrades)
flame cell - Answer-specialized cell that filters and removes excess water from the
body of a flatworm
flagella - Answer-whiplike tails found in one-celled organisms to aid in movement
fragmentation - Answer-A means of asexual reproduction whereby a single parent
breaks into parts that regenerate into whole new individuals.
fringing reef - Answer-directly attached to the shore of a volcanic island or continent
and has no lagoon associated with it
gastrodermis - Answer-in cnidarians, the layer of cells surrounding the digestive tract
gastrula - Answer-double-walled stage of the embryo resulting from invagination of
the blastula
gemmulation - Answer-Asexual reproduction of the sponge. Also a sort of
"hibernation" stage for the sponge, as this type of sponge only contains a
microphyle, spicules, and an archeocyte mass.
gemmule - Answer-group of archaeocytes surrounded by a tough layer of spicules;
produced by some sponges
gizzard - Answer-in earthworms, part of the digestive system in which food is ground
into smaller pieces; in birds, a muscular organ that helps in the mechanical
breakdown of food
glochidium larva - Answer-Bivalved larval stage of freshwater mussels; parasitic
larva seem in bivalves and is complete with 2 large raptorial teeth on the edge of the
shell that it uses to in-bed itself in fish gills
gynogenesis - Answer-female parthenogenesis in which the embryo contains only
maternal chromosomes due to the failure of the sperm to fuse with the egg nucleus
Complete Answers
chitin - Answer-A structural polysaccharide, consisting of amino sugar monomers,
found in many fungal cell walls and in the exoskeletons of all arthropods.
chiton - Answer-primitive elongated bilaterally symmetrical marine mollusk having a
mantle covered with eight calcareous plates
choanoblasts - Answer-One of several cellular elements within the syncytial tissue of
a hexactinellid sponge; bear flagellated extensions called collar bodies.
choanocytes - Answer-flagellated collar cells, generate a water current through the
sponge and ingest suspended food
chorion - Answer-outermost layer of the two membranes surrounding the embryo; it
forms the fetal part of the placenta
cilia - Answer-short structures projecting from a cell and containing bundles of
microtubules that move a cell through its surroundings or move fluid over the cell's
surface
circumenteric ring - Answer-part of a pseudocoelomate nervous system
clade - Answer-a group of biological taxa or species that share features inherited
from a common ancestor
cnidocyte - Answer-A specialized cell unique to the phylum Cnidaria; contains a
capsule-like organelle housing a coiled thread that, when discharged, explodes
outward and functions in prey capture or defense.
coelom - Answer-fluid-filled body cavity lined with mesoderm
collagen - Answer-a fibrous scleroprotein in bone and cartilage and tendon and other
connective tissue
collenocytes - Answer-A type of cell in sponges that is star-shaped and apparently
contractile.
colonial flagellate hypothesis - Answer-1. Metazoans from colonial flagellates
2. Molecular data (RNA) agree
3. Metazoans - related to fungi &
choanoflagellates
4. Opisthokonta (clade)
,commensalism - Answer-the relation between two different kinds of organisms when
one receives benefits from the other without damaging it
complete digestive system - Answer-animal has mouth and anus; food travels one
way
conispiral - Answer-more advanced kind of Gastropod shell where the right kidney,
auricle and kidney are lost to allow the Gastropod to completely withdraw into the
cell.
corona - Answer-head or upper end of a structure; ciliated disk on anterior end of
rotifers
crystalline style - Answer-Class Bivalvia; gelatinous rod that projects into the
stomach; the rotating of the style frees digestive enzymes and rolls the food mass
ctenidia - Answer-Comblike structures, especially gills of molluscs; also applied to
comb plates of ctenophora
cuticle - Answer-hard outer covering or case of certain organisms such as
arthropods and turtles
cysticeri - Answer-A type of juvenile tapeworm composed of a solid-bodied cyst
containing an invaginated scolex; contracts with cysticercus
cytokinesis - Answer-organic process consisting of the division of the cytoplasm of a
cell following karyokinesis bringing about the separation into two daughter cells
determinate cleavage - Answer-A type of embryonic development in protostomes
that rigidly casts the developmental fate of each embryonic cell very early.
deuterostome - Answer-animal whose anus is formed from the blastopore of a
blastula
dioecious - Answer-having male and female reproductive organs in separate plants
or animals
diploid - Answer-(genetics) an organism or cell having two sets of chromosomes or
twice the haploid number
discoidal cleavage - Answer-In an early embryo, cell division occurs within a small
disc of cytoplasm atop a large mass of yolk.
ectoderm - Answer-the outer germ layer that develops into skin and nervous tissue
endoderm - Answer-the inner germ layer that develops into the lining of the digestive
and respiratory systems
, enterocoelous - Answer-The type of development found in deuterostomes. The
coelomic cavities form when mesoderm buds from the wall of the archenteron and
hollows out.
ephyra - Answer-Tiny medusae that comes off the polyps in sexual reproduction
epitheliomuscular cells - Answer-form most of the epidermis and serve both for
contraction and for muscular contraction. Bases of these are myofibrils, which when
contracted shorten the body or tentacles.
epizooites - Answer-Rotiferians which live on other animals but are not parasitic
eutely - Answer-Development in which all adults have the same, fixed number of
cells (rotifers, nematodes, tardigrades)
flame cell - Answer-specialized cell that filters and removes excess water from the
body of a flatworm
flagella - Answer-whiplike tails found in one-celled organisms to aid in movement
fragmentation - Answer-A means of asexual reproduction whereby a single parent
breaks into parts that regenerate into whole new individuals.
fringing reef - Answer-directly attached to the shore of a volcanic island or continent
and has no lagoon associated with it
gastrodermis - Answer-in cnidarians, the layer of cells surrounding the digestive tract
gastrula - Answer-double-walled stage of the embryo resulting from invagination of
the blastula
gemmulation - Answer-Asexual reproduction of the sponge. Also a sort of
"hibernation" stage for the sponge, as this type of sponge only contains a
microphyle, spicules, and an archeocyte mass.
gemmule - Answer-group of archaeocytes surrounded by a tough layer of spicules;
produced by some sponges
gizzard - Answer-in earthworms, part of the digestive system in which food is ground
into smaller pieces; in birds, a muscular organ that helps in the mechanical
breakdown of food
glochidium larva - Answer-Bivalved larval stage of freshwater mussels; parasitic
larva seem in bivalves and is complete with 2 large raptorial teeth on the edge of the
shell that it uses to in-bed itself in fish gills
gynogenesis - Answer-female parthenogenesis in which the embryo contains only
maternal chromosomes due to the failure of the sperm to fuse with the egg nucleus
