chapter 32 animal diversity and evolution of body plans
Select the key innovations in animal evolution.
Body cavity Segmentation Symmetry Tissues Various patterns of embryonic development
What are the flagellated cells that line the internal cavity of a sponge and help water flow through the Ostia called?
Choanocytes
Members of what phylum are characterized by a diploblastic, radially symmetrical body plan and, while not having organs and organ systems, possess distinct tissues?
Cnidaria
What organisms are included in the phylum Ctenophora?
Comb jellies
Comb jellies make up the phylum
Ctenophora
Which of the following phyla belong to the Deuterostomes?
Echinoderms Chordates
What clade includes all animals that have true tissues and body symmetry?
Eumetazoa
True or false: As molecular data has become widely available most of what was previously known about the deep relationships of animal phyla to each other has been proven wrong.
False
Which of the following correctly describes how a heterotrophic organism obtains energy and organic molecules?
Ingesting other organisms
Which of the following accurately describes the pseudocoelom?
It is a body cavity that develops embryologically between the mesoderm and endoderm.
Animals that undergo embryonic development where the embryonic blastopore develops to become the animal's mouth are
Protosomes
Which of the following refers to a type of body plan where an animal's body is divided into nearly identical units.
Segmented body plan
Choose the statement that most accurately describes the presence of tissues in animals.
Specialized tissues are found in all animals except sponges.
The only animals that lack any form of body symmetry are
Sponges
Which of the following statement best describes sponges?
Sponges have several types of cells that perform different functions
Which of the following accurately describes animals with a segmented body plan?
The animal's body is divided into nearly identical units.
Which of the following are characteristics of cnidarians?
They are made of distinct tissues. They are diploblastic. They have radial symmetry.
Which of the following statements about sponges is true?
They are multicellular but do not have true tissues.
Which of the following best explains why animals are considered monophyletic?
They have a common ancestor
Choose all characteristics of acoel flatworms.
They have bilateral symmetry. Their mouth leads to a solid digestive syncytium. They do not have a coelom.
Noncoelomate invertebrates, such as sponges and jellyfish, and noncoelomate worms, are evolutionarily important because of which of the following statements?
They possessed the basic animal body plan from which the body plan of all other animals evolved.
Which of the following is most true regarding molecular and traditional analysis of Metazoa?
Though there are differences between the two phylogenies, there is much agreement in the deep parts of the evolutionary tree.
How many clades does the Bilateria comprise?
Two
Animals that lack a coelom do not form a monophyletic clade; therefore,
animal classification cannot be based on whether or not an animal has a coelom
Sponges can reproduce simply by breaking into fragments, each of which continues to grow as a new individual.
asexually
Most sponges are
asymmetrical
The five key innovations in animal evolution include tissues, a body , various patterns of embryonic development, segmentation, and .
cavity, Symmetry
The flagellated cells that line the internal cavity of a sponge and help water flow through the ostia are known as
choanocytes
The largest class of is Anthozoa.
cnidaria
As their name implies, flatworms in the phylum Acoela lack
coelom
Based on ample evidence, the echinoderms and chordates form a monophyletic clade called the
deuterostomia
In contrast to Parazoa, the includes all animals that have true tissues and body symmetry.
eumetazoa
All animals descend from a common ancestor and are therefore
monophyletic
Protostomes are animals in which the embryonic blastopore becomes the
mouth
Despite their simplicity, the appearance of noncoelomate invertebrates was very important - these organisms possessed the basic animal body , from which that of all other animals evolved.
plan
A body cavity called the develops in an animal embryo between the mesoderm and endoderm.
pseudocoelom
In all animals except , cells differentiate into specialized which are groups of cells that take on particular functions in the animal's body.
sponges, tissues
All animals exhibit some form of body symmetry except
sponges.
Most sponges do not have a definite and do not possess tissues.
symmetry
Which of the following describes asexual reproduction in sponges?
A sponge can break into fragments and each fragment can become an individual.
Within phylum Cnidaria, the class that includes the most species is
Anthozoa
Why can't we base animal classification on whether or not an animal has a coelom?
Because the acoelomate and pseudocoelomate conditions have evolved multiple times
This group of animals is characterized by a transition to bilateral symmetry.
Bilateria
Protosteoms can be divided into two clades; and
Lophotrochozoa, Ecdysozoa
Select the terms that accurately describe an organism that obtains energy and organic molecules by ingesting other organisms
Omnivore Heterotroph Carnivore Detritivore
