Zool 250 Midterm 1: Metazoa and placozoa, porifera Exam
Questions and Answers with Verified Solutions | Latest 2026 Update
Q: What character states define Kingdom Anamalia?
Answer:
1) animals are multicellular (except gametes)
-hence alternative name of Metazoa
-to distinguish from single-celled protozoans, protozoa being an old name for
non-photosynthetic single celled eukaryotes
lack cell wall
-unlike other major groups of multicellular eukaryotes, plants and fungi
are chemoheterotrophic: cannot make own carbon-based food source, get it from
carbon molecules made by other organisms
are (mostly) sexual: motile haploid sperm fertilizes larger non-motile haploid egg
to make diploid zygote
are animate: are capable of moving entire multicellular body in at least one stage in
life cycle
Q: meta
Answer:
later
Meta also means change which is a little bit confusing
Q: zoo
Answer:
animal
Q: prot
Answer:
early, first
Q: A few features are unique to animals and may act as synapomorphies for the
entirety of the kingdom or for large clades within it
Answer:
1) gastrulation and embryonic tissue layering
,0 0 unique types of intercellular junctions
Type IV collagen
Type IV collagen is a main constituent of the basal lamina, the epithelium-secreted
layer of the basement membrane
striated myofibrils and actin-myosin contractile elements
Q: definition of animal
Answer:
a heterotrophic multicellular eukaryote that undergoes embryogenesis via tissue
layering
Q: gastrulation and embryonic tissue layering
Answer:
most animals share similar pattern of fertilization and early embryonic
development
have haploid gametes of different sizes
-anisogamy: small motile sperm, large nonmotile eggs
Diploid zygote initially undergoes a number of mitatic cell divisions without
growth of cells between divisions
-cleavage
eventually a hollow ball of cells is formed
-blastula
Blastula invaginates (folds into itself) at one end
-gastrulation
gastrula has 2 clear layer of cells: all animals, even sponges, have embryos that go
through this 2 layered stage
Q: in Eumetozoa, further embryonic development results in the outer layer
Answer:
> ectoderm, inner layer -> endoderm
much after gastrulation there are two major patterns of development that occur in
animals
-direct or indirect development
Q: ansiogamy
, Answer:
small motile sperm, large nonmotile eggs
Q: an
Answer:
not
Q: iso
Answer:
same
Q: hollow ball of cells
Answer:
blastula
Q: blast
Answer:
sprout, germinate
Q: gaster
Answer:
stomach
Q: gastrulation
Answer:
Blastula invaginates (folds into itself) at one end
-gastrulation
Q: gastrula
Answer:
has 2 clear layer of cells: all animals, even sponges, have embryos that go through
this 2layered stage
Q: direct development
Answer:
occurs when embryo gradually develops toward adult form without sudden
changes in morphology
Questions and Answers with Verified Solutions | Latest 2026 Update
Q: What character states define Kingdom Anamalia?
Answer:
1) animals are multicellular (except gametes)
-hence alternative name of Metazoa
-to distinguish from single-celled protozoans, protozoa being an old name for
non-photosynthetic single celled eukaryotes
lack cell wall
-unlike other major groups of multicellular eukaryotes, plants and fungi
are chemoheterotrophic: cannot make own carbon-based food source, get it from
carbon molecules made by other organisms
are (mostly) sexual: motile haploid sperm fertilizes larger non-motile haploid egg
to make diploid zygote
are animate: are capable of moving entire multicellular body in at least one stage in
life cycle
Q: meta
Answer:
later
Meta also means change which is a little bit confusing
Q: zoo
Answer:
animal
Q: prot
Answer:
early, first
Q: A few features are unique to animals and may act as synapomorphies for the
entirety of the kingdom or for large clades within it
Answer:
1) gastrulation and embryonic tissue layering
,0 0 unique types of intercellular junctions
Type IV collagen
Type IV collagen is a main constituent of the basal lamina, the epithelium-secreted
layer of the basement membrane
striated myofibrils and actin-myosin contractile elements
Q: definition of animal
Answer:
a heterotrophic multicellular eukaryote that undergoes embryogenesis via tissue
layering
Q: gastrulation and embryonic tissue layering
Answer:
most animals share similar pattern of fertilization and early embryonic
development
have haploid gametes of different sizes
-anisogamy: small motile sperm, large nonmotile eggs
Diploid zygote initially undergoes a number of mitatic cell divisions without
growth of cells between divisions
-cleavage
eventually a hollow ball of cells is formed
-blastula
Blastula invaginates (folds into itself) at one end
-gastrulation
gastrula has 2 clear layer of cells: all animals, even sponges, have embryos that go
through this 2 layered stage
Q: in Eumetozoa, further embryonic development results in the outer layer
Answer:
> ectoderm, inner layer -> endoderm
much after gastrulation there are two major patterns of development that occur in
animals
-direct or indirect development
Q: ansiogamy
, Answer:
small motile sperm, large nonmotile eggs
Q: an
Answer:
not
Q: iso
Answer:
same
Q: hollow ball of cells
Answer:
blastula
Q: blast
Answer:
sprout, germinate
Q: gaster
Answer:
stomach
Q: gastrulation
Answer:
Blastula invaginates (folds into itself) at one end
-gastrulation
Q: gastrula
Answer:
has 2 clear layer of cells: all animals, even sponges, have embryos that go through
this 2layered stage
Q: direct development
Answer:
occurs when embryo gradually develops toward adult form without sudden
changes in morphology
