Zoology 250 Midterm Exam Questions and Answers with Verified
Solutions | Latest 2026 Update
Q: Which of these features seems to be a synapomorphy of the cnidarian
subphylum Medusozoa?
two layers of epitheliomuscular cells
linear rather than circular mitochondrial DNA
presence of a siphonoglyph
loss of the polyp stage
presence of a complete gut
Answer:
b
Q: Name a phylum of Metazoa that can reproduce sexually but does not have
gonads.
Answer:
Porifera
Q: For which of these phyla was there a recent controversy about the presence of
an anal opening?
Xenacoelomorpha
Ctenophora
Chaetognatha
Platyhelminthes
Nemertea
Answer:
b
Q: Primary endosymbiosis involves a eukaryotic cell taking on a as a symbiont
Answer:
free-living bacteria
Q: A triploblastic phylum that uses a toxin created by symbiotic bacteria.
Answer:
Chaetognatha
, 5425440 151838 When unfertilized eggs are able to develop into a functional
adult, this is called -
Parthenogenesis
6229984 153776 If an anthozoan polyp has more than 8 tentacles, then a
cross-section through it should show -
precisely 8 gastrovascular septa
Q: Which of these protist taxa include species that live endosymbiotically in the
guts of termites and cockroaches?
Answer:
Parabasalida
Q: Which of the following groups was placed into its current phylum based much
more on molecular evidence than on morphological evidence?
Answer:
Myxozoa
Q: Which of the following is true of all members of the Platyhelminthes?
Answer:
they have mesodermally derived muscles
Q: First being male and then, later in life, being female.
Answer:
Protandry
Q: A very simple excretory organ found in Platyhelminthes and some other
phyla.
Answer:
Protonephridia
Q: In the late 1990's, the accidental introduction of resulted in the recovery of
that had almost collapsed due to predation and competition from .
Answer:
a comb-jelly, fisheries, a different non-native ctenophore
Q: The cells responsible for a sponge's sneeze are the:
Solutions | Latest 2026 Update
Q: Which of these features seems to be a synapomorphy of the cnidarian
subphylum Medusozoa?
two layers of epitheliomuscular cells
linear rather than circular mitochondrial DNA
presence of a siphonoglyph
loss of the polyp stage
presence of a complete gut
Answer:
b
Q: Name a phylum of Metazoa that can reproduce sexually but does not have
gonads.
Answer:
Porifera
Q: For which of these phyla was there a recent controversy about the presence of
an anal opening?
Xenacoelomorpha
Ctenophora
Chaetognatha
Platyhelminthes
Nemertea
Answer:
b
Q: Primary endosymbiosis involves a eukaryotic cell taking on a as a symbiont
Answer:
free-living bacteria
Q: A triploblastic phylum that uses a toxin created by symbiotic bacteria.
Answer:
Chaetognatha
, 5425440 151838 When unfertilized eggs are able to develop into a functional
adult, this is called -
Parthenogenesis
6229984 153776 If an anthozoan polyp has more than 8 tentacles, then a
cross-section through it should show -
precisely 8 gastrovascular septa
Q: Which of these protist taxa include species that live endosymbiotically in the
guts of termites and cockroaches?
Answer:
Parabasalida
Q: Which of the following groups was placed into its current phylum based much
more on molecular evidence than on morphological evidence?
Answer:
Myxozoa
Q: Which of the following is true of all members of the Platyhelminthes?
Answer:
they have mesodermally derived muscles
Q: First being male and then, later in life, being female.
Answer:
Protandry
Q: A very simple excretory organ found in Platyhelminthes and some other
phyla.
Answer:
Protonephridia
Q: In the late 1990's, the accidental introduction of resulted in the recovery of
that had almost collapsed due to predation and competition from .
Answer:
a comb-jelly, fisheries, a different non-native ctenophore
Q: The cells responsible for a sponge's sneeze are the:
