Biology Exam Chapter 32 and 33

A graduate student finds an organism in a pond and thinks it is a freshwater sponge. A postdoctoral student thinks it looks more like an aquatic fungus. How can they decide whether it is an animal or a fungus?
Determine whether it is unicellular or multicellular.
Figure out whether it is autotrophic or heterotrophic.
Look for cell walls under a microscope.
See if it reproduces sexually.
See if it is a eukaryote or prokaryote.

Look for cell walls under a microscope.

Which of the following is (are) unique to animals?
flagellated gametes
heterotrophy
the structural carbohydrate, chitin
nervous system signal conduction and muscular movement

nervous system signal conduction and muscular movement

The larvae of some insects are merely small versions of the adult, whereas the larvae of other insects look completely different from adults, eat different foods, and may live in different habitats. Which of the following is most directly involved in the evolution of these variations in metamorphosis?
changes in the homeobox genes governing early development
artificial selection of sexually immature forms of insects
the origin of a brain
the evolution of meiosis

changes in the homeobox genes governing early development

Both animals and fungi are heterotrophic. What distinguishes animal heterotrophy from fungal heterotrophy is that most animals derive their nutrition by _____.
preying on animals
using enzymes to digest their food
consuming living, rather than dead, prey
ingesting it

ingesting it

What do animals ranging from corals to monkeys have in common?
number of embryonic tissue layers
presence of Hox genes
a mouth and an anus
type of body symmetry

presence of Hox genes

In individual insects of some species, whole chromosomes that carry larval genes are eliminated from the genomes of somatic cells at the time of metamorphosis. A consequence of this occurrence is that _____.
the descendants of these adults do not include a larval stage
metamorphosis can no longer occur among the descendents of such adults
we could not clone a larva from the somatic cells of such an adult insect
such species must reproduce only asexually

we could not clone a larva from the somatic cells of such an adult insect

All animals can trace their lineage to a common ancestor that lived in the _____.
Neoproterozoic era
Cenozoic
Pliocene
Jurassic
Devonian

Neoproterozoic era

The earliest ancestors of about half of all extant animal phyla can be traced back to the _____ explosion.
Devonian
Cambrian
Jurassic
Carboniferous
Pleistocene

Cambrian

Which of the following would you classify as something other than an animal?
choanoflagellates
jellyfish
sponges
coral

choanoflagellates

The evolution of animal species has been prolific (the estimates go into the millions and tens of millions). Much of this diversity is a result of the evolution of novel ways to _____.
reproduce
arrange cells into tissues
form an embryo and establish a basic body plan
sense, feed, and move

sense, feed, and move

Which statement is most consistent with the hypothesis that the Cambrian explosion was caused by the rise of predator-prey relationships? The fossil record reveals an increased incidence of _____.
organic material
worm burrows
larger animals
hard parts

hard parts

Whatever its ultimate cause(s), the Cambrian explosion is a prime example of _____.
a large meteor impact
adaptive radiation
mass extinction
evolutionary stasis

adaptive radiation

Which of the following is radially symmetrical?
a dog
a submarine sandwich
a doughnut
a spoon
an automobile

a doughnut

Gastrulation is the process that directly forms the _____.
muscles
organs
primary germ layers
blastula
central nervous system

primary germ layers

Which of the following is NOT a characteristic of all animals?
They are heterotrophic.
They are eukaryotes.
They are all multicellular.
They have tissues, organs, and organ systems.
They ingest their food.

They have tissues, organs, and organ systems.

An important trend in animal evolution was cephalization. An animal is said to show cephalization when it _____.
is large
has bilateral symmetry
has tissue specialization
has an aggregation of sensory neurons at the anterior end
has a hard, outer covering

has an aggregation of sensory neurons at the anterior end

Which of the following animals does NOT have a body cavity?
nematode
clam
flatworm
earthworm
mouse

flatworm

During embryological development, the anus forms before the mouth in _____.
flatworms
earthworms
arthropods
humans
slugs

humans

Which tissue type, or organ, is NOT correctly matched with its germ layer tissue?
stomach – endoderm
nervous – mesoderm
skin – ectoderm
muscular – mesoderm

nervous – mesoderm

In examining an unknown animal species during its embryonic development, how can you be sure what you are looking at is a protostome and not a deuterostome?
The animal is clearly bilaterally symmetrical.
There is evidence of cephalization.
You see a mouth, but not an anus.
The animal is triploblastic.

You see a mouth, but not an anus.

Use the following information to answer the question(s) below.

A student encounters an animal embryo at the eight-cell stage. The four smaller cells that comprise one hemisphere of the embryo seem to be rotated 45 degrees and to lie in the grooves between larger, underlying cells.

If we were to separate these eight cells and attempt to culture them individually, then what is most likely to happen?
All eight cells will die immediately.
Each cell may continue development, but only into a nonviable embryo that lacks many parts.
Each cell may develop into a full-sized, normal embryo.
Each cell may develop into a smaller-than-average, but otherwise normal, embryo.

Each cell may continue development, but only into a nonviable embryo that lacks many parts.

What was an early selective advantage of a coelom in animals? A coelom _____.
contributed to a hydrostatic skeleton, allowing greater range of motion
was a more efficient digestive system
allowed cephalization and the formation of a cerebral ganglion
allowed asexual and sexual reproduction

contributed to a hydrostatic skeleton, allowing greater range of motion

An organism that exhibits cephalization probably also _____.
is diploblastic
has a coelom
is bilaterally symmetrical
is segmented

is bilaterally symmetrical

Which of the following statements is correct?
Sponges are diploblastic animals.
All animals share a common ancestor.
Eumetazoans have three embryonic tissue layers.
The origin of all extant animal phyla can be traced to the Cambrian explosion.
Most animal phyla belong to the clade Radiata.

All animals share a common ancestor.

Among the characteristics unique to animals is
multicellularity.
sexual reproduction.
gastrulation.
heterotrophic nutrition.
flagellated sperm.

gastrulation.

Which of the following was probably the least important factor in bringing about the Cambrian explosion?
the accumulation of diverse adaptations, such as shells and different modes of locomotion
the accumulation of sufficient atmospheric oxygen to support the more active metabolism of mobile animals
the movement of animals onto land
the origin of Hox genes and other genetic changes affecting the regulation of developmental genes
the emergence of predator-prey relationships among animals

the movement of animals onto land

What is the key difference between a coelom and a pseudocoelom?
Only a coelom is fully lined with mesoderm tissue.
A coelom is a true body cavity, whereas a pseudocoelom is a false coelom that is not fully functional.
Pseudocoeloms arose early in animal evolution and evolved into coeloms.

Only a coelom is fully lined with mesoderm tissue.

Which feature of deuterostome development explains the formation of identical human twins?
In deuterostomes, the blastopore becomes the anus.
Deuterostomes have radial cleavage.
Deuterostomes have indeterminate development.

Deuterostomes have indeterminate development.

The animal phylum most like the protists that gave rise to the animal kingdom is _____.
Cnidaria
Lycophyta
Porifera
Echinodermata
Ctenophora

Porifera

One should expect to find cilia associated with the feeding apparatus of _____.
sponges
tapeworms
coral animals
annelids

sponges

Sponges _____.
have feeding cells called dinoflagellates
have larvae which are motile and move via the motion of cilia
have a nerve net but not a central nervous system
are the simplest diploblastic animals

have larvae which are motile and move via the motion of cilia

Which of the following is most likely to be aquatic?
mass feeder
fluid feeder
deposit feeder
suspension feeder

suspension feeder

Comb jellies may not be the most familiar animal to you, but they are critical in the food chain because they make up a significant portion of the planktonic biomass. Their feeding strategy is predatory and involves adhesives or mucus on their tentacles or other body parts. What feeding tactic do these animals use?
food-mass feeder
fluid feeder
deposit feeder
suspension feeder

suspension feeder

Which of the following can be found in the mesohyl of a sponge?
1. amoebocytes
2. spicules
3. spongin
4. zygotes
5. choanocytes
2, 3, 4
1, 2, 3, and 4
1, 2, 3, 4, and 5
1 and 2

1, 2, 3, and 4

Which of the following is a characteristic of cnidarians?
bilateral symmetry
mesoderm
an anus
gastrovascular cavity
radula

gastrovascular cavity

Most cnidarians are known to produce toxins. In fact, it has been claimed that one particular species produces the most deadly of all toxins on the planet. What feature of this group most likely evolved simultaneously with the evolution of these toxins?
asexual reproduction
diploblastic design
the medusa body form
a slow-moving or sessile lifestyle in the adult

a slow-moving or sessile lifestyle in the adult

In terms of food capture, which sponge cell is most similar to the cnidocyte of a cnidarian?
epidermal cell
pore cell
amoebocyte
choanocyte

choanocyte

Use the following information to answer the question(s) below.

An elementary school science teacher decided to liven up the classroom with a saltwater aquarium. Knowing that saltwater aquaria can be quite a hassle, the teacher proceeded stepwise. First, the teacher conditioned the water. Next, the teacher decided to stock the tank with various marine invertebrates, including a polychaete, a siliceous sponge, several bivalves, a shrimp, several sea anemones of different types, a colonial hydra, a few coral species, an ectoproct, a sea star, and several herbivorous gastropod varieties. Lastly, she added some vertebrates-a parrotfish and a clownfish. She arranged for daily feedings of copepods and feeder fish.

One day, Tommy, a student in an undersupervised class of forty fifth graders, got the urge to pet Nemo (the clownfish), who was swimming among the waving petals of a pretty underwater "flower" that had a big hole in the midst of the petals. Tommy giggled upon finding that these petals felt sticky. A few hours later, Tommy was in the nurse’s office with nausea and cramps. Microscopic examination of his fingers would probably have revealed the presence of _____.
spicules
spines
teeth marks
nematocysts

nematocysts

Which of the following is characteristic of the phylum Platyhelminthes?
They typically reproduce asexually.
They are radially symmetrical.
They are dorsoventrally flattened.
They are diploblastic.
They are all parasitic.

They are dorsoventrally flattened.

Ectoprocts and brachiopods are collectively referred to as _____.
eumetazoans
ecdysozoans
lophophorates
flatworms
trochophorates

lophophorates

Members of the phylum Mollusca _____.
are filter feeders
have tentacles surrounding a central mouth/anus
have closed circulatory systems
are soft-bodied and often covered by a shell
have segmented bodies and paired, jointed appendages

are soft-bodied and often covered by a shell

Which of the following is true of annelids?
They have pseudocoeloms.
They have a gastrovascular cavity.
They have an open circulatory system.
They perform gas exchange across their skin.
They have a nerve net.

They perform gas exchange across their skin.

A marine biologist dredges up a small animal from the bottom of the ocean. It is uniformly segmented, with short, stiff appendages and soft, flexible skin. It has a complete digestive system and a closed circulatory system, plus multiple true coeloms. Based on this, you determine that the animal must be a(n) _____.
mollusc
crustacean
roundworm
lancelet
annelid

annelid

You find what you believe is a new species of animal. Which of the following characteristics would enable you to argue that it is more closely related to a flatworm than it is to a roundworm?
It has a mouth and an anus.
It is shaped like a worm.
It has no coelom.
It is a suspension feeder.

It has no coelom.

What would be the best anatomical feature to look for to distinguish a gastropod from a chiton?
presence of a muscular foot
presence of a rasp-like feeding structure
number of shell plates
production of eggs

number of shell plates

What would be the most effective method of reducing the incidence of blood flukes in a human population?
avoid contact with rodent droppings
carefully wash all raw fruits and vegetables
reduce the mosquito population
reduce the population of the intermediate snail host

reduce the population of the intermediate snail host

Planarians lack dedicated respiratory and circulatory systems because _____.
none of their cells are far removed from the gastrovascular cavity or from the external environment
their body cavity, a pseudocoelom, carries out these functions
they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm
their flame bulbs can carry out respiratory and circulatory functions

none of their cells are far removed from the gastrovascular cavity or from the external environment

Which one of these mollusk groups can be classified as suspension feeders?
gastropods
cephalopods
bivalves
chitons

bivalves

What structure is responsible for gas exchange in most spiders?
Malpighian tubules
chelicerae
tracheal tubes
the pedipalp
book lungs

book lungs

Nematodes and arthropods both _____.
grow by shedding their exoskeleton
develop an anus from the blastopore (pore) formed in the gastrula stage
are suspension feeders
have ciliated larvae

grow by shedding their exoskeleton

Arthropod exoskeletons and mollusk shells both _____.
help retain moisture in terrestrial habitats
are comprised of the polysaccharide chitin
are secreted by the mantle
completely replace the hydrostatic skeleton

help retain moisture in terrestrial habitats

You find a multi-legged animal in your garden and want to determine if it is a centipede or a millipede. You take the animal to a university where a myriapodologist quickly tells you that you have found a centipede. Which of the following may have allowed her to make this distinction?
egg-laying
molting
segmentation
poisonous fangs

poisonous fangs

All arthropods _____.
1) undergo complete metamorphose
2) have jointed appendages
3) molt
4) have segmented bodies
5) have an exoskeleton or cuticle
2, 3, 4, 5
3 and 5
1, 4, 5
1, 2, and 4

2, 3, 4, 5

Which of the following are thought to be most closely related to humans?
jellies
earthworms
sea stars
snails
ants

sea stars

The water vascular system of echinoderms _____.
functions as a circulatory system that distributes nutrients to body cells
functions in locomotion and feeding
is analogous to the gastrovascular cavity of flatworms
is bilateral in organization, even though the adult animal is not bilaterally symmetrical

functions in locomotion and feeding

Which of the following animal groups is entirely aquatic?
Echinodermata
Crustacea
Mollusca
Nematoda

Echinodermata

Which phylum is characterized by animals that have a segmented body?
Porifera
Platyhelminthes
Cnidaria
Arthropoda
Mollusca

Arthropoda

Identify the features that distinguish animals from organisms in other multicellular kingdoms.
Select all that apply.
Select all that apply.
A. Animals are motile.
B. Animals are ingestive heterotrophs.
C. Animals have sensory organs at their anterior end.

Animals are ingestive heterotrophs.

Select all that apply.
Tapeworms lack a mouth and gastrovascular cavity.
Ectoprocts lack a distinct head.
Rotifers are smaller than many protists.

All of them are correct

Select all that apply.
All nematodes live in soil.
Some nematodes play important roles in nutrient cycling.
Nematodes lack a circulatory system and circular body wall muscles.

Some nematodes play important roles in nutrient cycling. Nematodes lack a circulatory system and circular body wall muscles.

The last common ancestor of all animals was probably a _____.
multicellular algae
multicellular fungus
unicellular chytrid
flagellated protist

flagellated protist

The distinction between sponges and other animal phyla is based mainly on the absence versus the presence of
true tissues.
a body cavity.
mesoderm.
a circulatory system.
a complete digestive tract.

true tissues

Arthropods invaded land about 100 million years before vertebrates did so. This most clearly implies that _____.
vertebrates evolved from arthropods
extant terrestrial arthropods are better adapted to terrestrial life than are extant terrestrial vertebrates
arthropods evolved before vertebrates did
arthropods have had more time to coevolve with land plants than have vertebrates

arthropods have had more time to coevolve with land plants than have vertebrates

Planarians lack dedicated respiratory and circulatory systems because _____.
their body cavity, a pseudocoelom, carries out these functions
none of their cells are far removed from the gastrovascular cavity or from the external environment
they lack mesoderm as embryos and, therefore, lack the adult tissues derived from mesoderm
their flame bulbs can carry out respiratory and circulatory functions

none of their cells are far removed from the gastrovascular cavity or from the external environment