Practice Questions for Exam 2
1.  

The term "resolving power" refers to which of the following?
the apparent increase in the size of an object
the source of the illumination
the depth of focus
the clarity of the image in showing two objects as separate
the type of cell being observed

2.  

A normal size range for a typical eukaryotic cell is _____.
0.1 nanometers
10 nanometers
100 nanometers
1–10 micrometers
10–100 micrometers
3.  

Communities that exist in the aphotic zone ultimately depend on food molecules manufactured by chemoautotrophic bacteria or _____.
algae and cyanobacteria that also live in the aphotic zone
algae and cyanobacteria that live in the photic zone
decomposers
scavengers
minerals found on the ocean bottom

4.  

After eutrophication (an increase in nutrients) due to sewage contamination, a lake often becomes inhospitable to fish. Why?
Nutrient input to a lake causes the explosive growth of algal and cyanobacterial populations. This reduces the penetration of light into the lake, which results in the death of all the fish.
Nutrient input to a lake poisons the fish.
Nutrient input to a lake causes the explosive growth of algal and cyanobacterial populations. Decomposition of dead algae and cyanobacteria by bacteria results in the depletion of oxygen in the water, which leads to the death of all the fish.
Nutrient input to a lake poisons the organisms that fish eat.
Nutrient input causes the death of algae and cyanobacteria and, thus, the ultimate sources of organic compounds in a lake ecosystem. Eventually, this reduces the availability of food for fish within the lake, leading to their death.
5.  

An ecologist might conduct research to answer which of the following questions?
How does the uneven heating of Earth's surface cause the movement of air and water masses?
How do genes specify protein construction?
How are different species of fish related (in an evolutionary sense) to each other?
How does caffeine affect the transmission of nerve impulses in humans?
How do tapeworms cope with life in the human intestine?

6.  

The sum of all Earth's ecosystems is called the __________.
stratosphere
lithosphere
biosphere
hydrosphere
troposphere

7.  

An immature frog (a tadpole) lives in a pond or lake. The adult frog lives on land, and it possesses special adaptations that permit it to survive in a terrestrial environment. These special adaptations _____.
help prevent the adult frog's body from drying out
maximize body temperature
permit the adult frog to maintain its internal water balance given the solute concentration of its hypotonic surroundings
maximize the rate of water loss from its body
maximize the interception of solar energy
8.  

Which one of the following statements about biomes is correct?
Each biome type occurs on every continent.
The major factors affecting the distribution of biomes are temperature and precipitation.
Most biomes are characterized by unique groups of particular species of plants and animals.
Most biomes are unaffected by human activity.
Each continent is home to a biome not found elsewhere on Earth.
9.  

Plankton consists of _____.
algae, cyanobacteria, and animals that drift near the surfaces of oceans only
photosynthetic organisms that drift near the surfaces of oceans, lakes, ponds, rivers, and streams
algae, cyanobacteria, and animals that belong to the benthic communities of oceans, lakes, ponds, rivers, and streams
algae, cyanobacteria, and animals that drift near the surfaces of oceans, lakes, ponds, rivers, and streams
algae, cyanobacteria, and animals that occupy the aphotic zones of oceans, lakes, and ponds
10.  

Rooted plants are found only in the __________ zone of a lake.
pelagic
nektonic
limnetic
littoral
profundal
11.  

Protists are a diverse group of organisms that includes _____.
plants
algae
protozoans
fungi
algae and protozoans
12.  

The algal groups most commonly found in freshwater ecosystems are __________.
brown algae and chlorophytes
red algae and brown algae
chlorophytes and diatoms
dinoflagellates and diatoms
none of these
13.  

Some protozoans, such as Amoeba and Paramecium, have special organelles that continually eliminate excess water from the cell. The presence of these organelles tells you that the protozoan is adapted to live in _________.
a terrestrial environment
human blood
a freshwater environment
the ocean
a hypertonic environment
14.  

Which of these groups includes unicellular organisms with unique overlapping cell walls?
diatoms
dinoflagellates
euglenoids
ciliates
apicomplexans
15.  

Which of these groups has cells with walls made of silica?
diatoms
dinoflagellates
euglenoids
ciliates
apicomplexans
16.  

Animals probably evolved from colonial protists. How do animals differ from these protist ancestors?
The protists were prokaryotic.
Animals have more specialized cells.
The protists were heterotrophic.
The protists were autotrophic.
Animals are able to reproduce.
17.  

"Cephalization" refers to having _____.
radial symmetry
a right and a left side
a head end
a dorsal and a ventral surface
ectoderm
18.  

Which of the following is NOT a characteristic of cnidarians?
gastrovascular cavity
cnidocytes
mesoderm
nematocysts
radial symmetry
19.  

A true coelom is ____________.
a body cavity lined with endoderm
a body cavity lined with endoderm and mesoderm
a body cavity lined with mesoderm
a thoracic body cavity
an abdominal body cavity
20.  

The presence of a coelom is advantageous because _____.
it allows for a third embryonic germ layer
it permits the development of an open circulatory system
it allows room for the development and movement of internal organs
it is necessary for a complete digestive tract
of all of these
21.  

Which of the following are found in members of the phylum Cnidaria?
exoskeleton, radial symmetry
a mantle for respiration, radial symmetry
endoskeleton, bilateral symmetry
stinging cells, radial symmetry
stinging cells, bilateral symmetry

22.  

Many cnidarians go through both a motile and a sessile (attached) stage during their life cycle. The attached stage is called a(n) _____.
embryo
medusa
larva
mesoglea
polyp
23.  

A distinctive feature of the Cnidaria is _____.
a complete digestive tract
nematocysts
bilateral symmetry
all of the above
none of the above
24.  

Which of the following best illustrates homeostasis?
All the cells in the body have much the same chemical composition.
Cells of the skin are constantly worn off and replaced.
When blood CO2 increases, you breathe faster and get rid of CO2.
All organs are composed of the same four kinds of tissues.
The lung has a large surface for exchange of gases.
25.  

Which one of the following animals would you expect to consume food at the highest rate (kilograms of food per kilogram of body weight per day)?
dog
hummingbird
human
elephant
eagle
26.  

Identify the correct statement about nutrition and digestion.
"Feeding" and "digestion" are synonyms.
Chemical digestion precedes physical digestion in wolves.
Absorption involves monomers passing through intestinal walls.
Elimination rids the body of overly large nutrient molecules.
Monomers are hydrolyzed into macromolecules during digestion.

27.  

Which part of a chicken's digestive system grinds food with sand or gravel?
gastrovascular cavity
gizzard
crop
pharynx
stomach
28.  

Which response FAILS to explain why large animals require a circulatory system?
Large animals require more oxygen and nutrients than small animals.
The force of gravity has a more significant impact in larger animals.
Diffusion is inadequate to move oxygen from the surface into all parts of a large animal's body.
Large animals do not have a gastrovascular cavity and must compensate for it with a circulatory system.
A rapid transit system for nutrients is necessary to sustain life in bulky animals.

29.  

Which animal has a closed vascular system?
jelly
snail
fish
beetle
crayfish
30.  

Closed circulatory systems ____________.
have capillaries
lack veins
lack a heart
have hemolymph
all of these are true

31.  

Which one of the following is NOT a function of the circulatory system?
producing mucus
transporting nutrients
fighting disease
moving wastes
maintaining body temperature

32.  

In a fish, blood circulates through ____, while in a mammal, it circulates through ____.
two circuits ... four circuits
one circuit ... two circuits
four circuits ... two circuits
one circuit ... four circuits
two circuits ... one circuit
33.  

In order for a body surface to be a respiratory surface, it must be _____.
thick, dry, and covered with hair
moist and glandular
expansive
thin and moist
internal

34.  

Which is NOT an essential feature for an animal's gas exchange surface?
large surface area in proportion to body size
a protective, wear-resistant covering
thin cell layers
living cells
continuous moistness

35.  

Countercurrent exchange in the gills of a fish _____.
speeds up the flow of water through the gills
maintains a gradient that enhances diffusion
enables the fish to obtain oxygen while swimming backward
means that blood and water flow in the same direction
interferes with the efficient absorption of oxygen

36.  

Which respiratory organ is most often found only in fully aquatic animals?
tracheae
lungs
capillaries
skin surface
gills

37.  

What adjustments would clearly make countercurrent exchange more efficient in extracting oxygen from water running through fish gills?
hemoglobin with a greater affinity for oxygen
proportionally larger gills to body size
better ventilation
slower heart rate
warmer water

38.  

Which of the following normally contains the highest concentration of oxygen?
body cells
inhaled air
air in the alveoli
blood entering the lungs
air leaving the lungs
39.  

During evolutionary refinements that led from fish to mammals, why was a shift from gills to lungs necessary?
Gills are not as efficient as lungs in picking up oxygen.
Gills are too small to service a mammal's need for oxygen.
Protecting gas-exchange surfaces from desiccation is difficult in terrestrial environments.
Air has a higher oxygen content than water, so gills were no longer necessary.
Gills work only in water; lungs work only on land.
40.  

In the alveoli and lung capillaries, CO2 and O2 are exchanged by means of _____.
diffusion
active transport
endocytosis
an exchange pump mechanism
osmosis
41.  

Which one of the following statements about the breathing methods of mammals and birds is true?
The mammalian system can extract the larger amount of oxygen at a given partial pressure of O2.
Both are positive-pressure systems.
The system of mammals is negative-pressure, but birds have a positive-pressure system.
The gas exchange system of mammals is confined to the thoracic cavity, but that of birds is not.
Air flows unidirectionally in both groups.
42.  

What effect does relaxing a tense abdomen during diaphragm contraction have on breathing?
It has no significant effect.
It decreases the residual volume of air in the lungs.
It becomes more difficult to expand the lungs.
The diaphragm moves higher into the chest cavity.
It increases the vital capacity of the lungs
43.  

By definition, an ectotherm _____.
is cold-blooded
is warm-blooded
obtains most of its heat from its environment
can generate enough metabolic heat to keep its body temperature above that of its surroundings
has a body temperature that varies considerably

44.  

The term "endotherm" refers specifically to _____.
a warm-blooded animal
a cold-blooded animal
an animal that gets most of its body heat from its metabolism
an animal that temporarily abandons warm-bloodedness
an animal that regulates its body temperature by its behavior

45.  

Which of the following animals are endotherms?
all animals
amphibians and reptiles
arthropods
reptiles, birds, and mammals
birds and mammals
46.  

Freshwater fish excrete a large amount of very dilute urine. What is the best explanation for this?
Because they live in a hypotonic solution, their cells take up an excess of water that must be excreted.
Because they live in a hypotonic solution, their cells tend to accumulate a lot of solute that must be excreted.
Because they live in a hypertonic solution, their cells take up an excess of water that must be excreted.
Because they live in a hypertonic solution, their cells tend to accumulate a lot of solute that must be excreted.
Because animals must live in an isotonic solution, they excrete solutes to make the concentration of solutes in the water equal to the concentration of solutes in their cells.

47.  

In a marine environment, animals that are isotonic relative to their environment _____.
experience no net water loss by osmosis
experience significant water gain by osmosis
experience significant water loss by osmosis
must expend energy on the active transport of solutes from their bodies to the environment
do not exist
48.  

The gamete of a female has __________ chromosomes as(than) the gamete of the male.
the same number of
fewer
more
all of the above
none of the above

49.  

Which reproductive method is used most frequently by mammals?
fragmentation
budding
regeneration
external fertilization
internal fertilization

ANSWERS: 1-D, 2-E, 3-B, 4-C, 5-E, 6-C, 7-A, 8-B, 9-D, 10-D, 11-E, 12-C, 13-C, 14-A, 15-A, 16-B, 17-C, 18-C, 19-C, 20-C, 21-D, 22-E, 23-B, 24-C, 25-B, 26-C, 27-B, 28-D, 29-C, 30-A, 31-A, 32-B, 33-D, 34-B, 35-B, 36-E, 37-A, 38-B, 39-C, 40-A, 41-D, 42-E, 43-C, 44-C, 45-E, 46-C, 47-A,  48-A, 49-E