BIOL 2251 Exam 2 Homework Questions With
Complete Answers
The simplest of canal systems is found in the - ANSWER asconoids
The minute, needle-like structures that act as a skeletal support system in sponges are
called _________________. - ANSWER Spicules
The most complex and the most common body form of sponges is found in the -
ANSWER leuconoids
Calcareous or siliceous elements of the sponge body wall provide support. These
elements are called - ANSWER spicules
The water outlet in sponges is known as a/an __________________. - ANSWER osculum
Which is NOT a trait of sponges? - ANSWER Water enters through the osculum
The order in which a drop of ink would pass by the structures in an ascon sponge is -
ANSWER ostia-spongocoel-osculum
True or False: Chemical secretions, produced as sponges and bacteria live in symbiotic
relationships, are proving important as therapies for human disease. - ANSWER True
The traditional view of Cnidarians relative to germ layers is that Cnidaria possess -
ANSWER two germ layers, ectoderm and endoderm
A hydra moves by - ANSWER epitheliomuscular cells in the epidermis.
, True or False: Though cnidarians are considered animals, they can make their own food
and are nonpredatory - ANSWER False
Hydra reproduces asexually by - ANSWER buds
Ctenophores capture food by - ANSWER colloblasts
The _____ stage is best adapted for cnidarians living in colonies while the ____ stage
helps in dispersal and survival in open oceans. - ANSWER Polyp, medusa
Cnidarians are found most abundantly in which of the following habitats? - ANSWER
Shallow marine habitats
How does Hydra reproduce sexually? - ANSWER The polyp body wall can produce both
ovaries and testes that make eggs and sperm, respectively.
The function of the rhopalium is - ANSWER sensory
Which are characteristics of members of the Xenoturbellids? Select all that apply. -
ANSWER Ring furrow, Side furrow, Longitudinal muscles
Worms that lack a coelom or a pseudocoel are termed _____________ animals. - ANSWER
acoelomate
The name of the free-swimming, ciliated stage that hatches from a trematode egg is the
- ANSWER miracidium
Animals with three well-defined germ layers and that have one solid mass of tissue
rather than tissues and organs nestled inside a body cavity are - ANSWER acoelomate
and triploblastic.
Complete Answers
The simplest of canal systems is found in the - ANSWER asconoids
The minute, needle-like structures that act as a skeletal support system in sponges are
called _________________. - ANSWER Spicules
The most complex and the most common body form of sponges is found in the -
ANSWER leuconoids
Calcareous or siliceous elements of the sponge body wall provide support. These
elements are called - ANSWER spicules
The water outlet in sponges is known as a/an __________________. - ANSWER osculum
Which is NOT a trait of sponges? - ANSWER Water enters through the osculum
The order in which a drop of ink would pass by the structures in an ascon sponge is -
ANSWER ostia-spongocoel-osculum
True or False: Chemical secretions, produced as sponges and bacteria live in symbiotic
relationships, are proving important as therapies for human disease. - ANSWER True
The traditional view of Cnidarians relative to germ layers is that Cnidaria possess -
ANSWER two germ layers, ectoderm and endoderm
A hydra moves by - ANSWER epitheliomuscular cells in the epidermis.
, True or False: Though cnidarians are considered animals, they can make their own food
and are nonpredatory - ANSWER False
Hydra reproduces asexually by - ANSWER buds
Ctenophores capture food by - ANSWER colloblasts
The _____ stage is best adapted for cnidarians living in colonies while the ____ stage
helps in dispersal and survival in open oceans. - ANSWER Polyp, medusa
Cnidarians are found most abundantly in which of the following habitats? - ANSWER
Shallow marine habitats
How does Hydra reproduce sexually? - ANSWER The polyp body wall can produce both
ovaries and testes that make eggs and sperm, respectively.
The function of the rhopalium is - ANSWER sensory
Which are characteristics of members of the Xenoturbellids? Select all that apply. -
ANSWER Ring furrow, Side furrow, Longitudinal muscles
Worms that lack a coelom or a pseudocoel are termed _____________ animals. - ANSWER
acoelomate
The name of the free-swimming, ciliated stage that hatches from a trematode egg is the
- ANSWER miracidium
Animals with three well-defined germ layers and that have one solid mass of tissue
rather than tissues and organs nestled inside a body cavity are - ANSWER acoelomate
and triploblastic.
