bio final Flashcards
(280 cards)
1
Q
symmetry: living attached to a substrate
A
sessile symmetry
2
Q
symmetry: drifting or weakly swimming, such as jellyfish
A
planktonic symmetry
3
Q
symmetry: animals move actively from place to place
A
bilateral symmetry
4
Q
what animals lack tissues?
A
sponges
5
Q
collections of specialized cells that act as a functional unit
A
tissues
6
Q
layers that form the various tissues and organs of the body
A
germ layers
7
Q
the germ layer covering the surface of the embryo
A
ectoderm
8
Q
the innermost germ layer that lines the pouch that forms during gastrulation
A
endoderm
9
Q
animal groups that have only these two germ layers (endoderm and ectoderm)
A
diploblastic
10
Q
the third germ layer that all bilaterally symmetrical animals have
A
mesoderm
11
Q
animals that are bilaterally symmetric are said to be (germ layer name)
A
triploblastic
12
Q
a fluid or air-filled space located between the digestive tract and the outer body wall
A
body cavity
13
Q
a body cavity that forms from tissue derived from mesoderm (fluid cushions suspended organs)
A
coelom
14
Q
animals possessing coeloms are called
A
coelomates
15
Q
a body cavity that forms between the mesoderm and endoderm (contains hemolymph that transports nutrients and waste)
A
hemocoel
16
Q
fluid that is analogous to your blood and is circulated through the body cavity in an open system by the heart
A
hemolymph
17
Q
animals with only a hemocoel
A
pseudocoelomates
18
Q
animals that dont require an internal transport system
A
acoelomates
19
Q
developmental mode distinguished by the development of the mouth from the blastophore (spiral cleavage and body cavity forming when solid masses of mesoderm split)
A
protosome development
20
Q
developmental mode distinguished by the development of the anus from the blastophore (radial cleavage and body cavity forming as outpockets of mesodermal tissue)
A
deuterostome development
21
Q
planes of cell division are diagonal to the vertical axis of the embryo
A
spiral cleavage
22
Q
cleavage of protostome developmental animals that rigidly determines the fate of each embryonic cell
A
determinate cleavage
23
Q
deuterostome development cleavage that has planes either parallel or perpendicular to the vertical axis of the embryo
A
radial cleavage
24
Q
deuterostome development cleavage where each cell produced by early cleavage divisions retains the capacity to develop into a complete embryo
A
indeterminate cleavage
25
during gastrulation, an embryo's developing digestive tube initially forms into a blind pouch called
archenteron
26
in this process of animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo (the gastrula)
gastrulation
27
the indentation that during gastrulation leads to the formation of the archenteron
blastophore
28
animals that lack a backbone
invertebrates
29
a lineage that diverged from other animals early in the history of the group
basal animals
30
animals in the phylum Porifera
sponges
31
animals that filter out food particles suspended in the surrounding water as they draw it through their body are called
filter feeders
32
central cavity in sponges where water is drawn through the pores
spongocoel
33
the large opening that water flows out of after going through the spongocoel
osculum
34
flagellated "collar" cells that line the interior of the spongocoel that engulf bacteria and other food particles by phagocytosis
choanocytes
35
gelatinous region that separates the two layers of cells in a sponge body
mesohyl
36
cells of a sponge that move through the mesohyl and use pseudopodia to take up food from choanocytes and digest it
amoebocytes
37
amoebocytes capable of becoming other types of sponge cells for flexibility and shape are called
totipotent
38
sponges that have individual functions as both male and female in sexual reproduction by producing sperm and eggs are called
hermaphrodites
39
a compound created from marine sponges that can kill both cancer cells and penicillin-resistant strains of strep
cribrostatin
40
animals in the phylum Cnidaria
hydras, corals, and jellyfish
41
body plan of a cnidarian that is a sac with a central digestive compartment that functions as a mouth and anus
gastrovascular cavity
42
cylindrical forms that adhere to the substrate of a cnidarian by the aboral end of their body and extends to their tentacles, waiting for prey (hydras and sea anemones)
polyps
43
a flattened , mouth-down version of the polyp that moves freely in the water by drifting and contractions (jellyfish)
medusa
44
predators with no brain (nerve net) that use tentacles arranged in a ring around the mouth to capture prey and push food into the gastrovascular cavity are in this phylum
Cnidaria
45
cells on tentacles that are unique to cnidarians functioning in defense and prey capture
cnidocytes
46
specialized cnidae that contain a stinging thread that can penetrate the body surface of prey
nematocysts
47
capsule-like organelles of cnidocytes that are capable of exploding outward and give Cnidaria its name
cnidae
48
what animals are in the phylum Platyhelminthes
flatworms, flukes, and tapeworms
49
although flatworms are tripoblastic...
they lack a body cavity and use diffusion
50
networks of tubules in flatworms with ciliated structures called flame bulbs that pull fluid through branched ducts opening to the outside
protonephridia
51
more than half of the known species of rhabditophorans live as ______ in or on other animals
parasites
52
parasites can be places into subgroups of
trematodes and tapeworms
53
type of parasite that require an intermediate host in which larvae develop before infecting the final host; most species have complex life cycles with alternating sexual and asexual stages
trematodes
54
type of parasite that live inside vertebrates, including humans; anterior end (scolex) is armed with suckers and hooks that attach the intestinal lining to the host
tapeworm
55
tapeworms lack a ... and instead absorb nutrients released by digestion in the host's intestine
mouth and gastrovascular cavity
56
a long ribbon of these little sacs of sex organs in a tapeworm that are posterior to the scolex
proglottids
57
a human can acquire a tapeworm larvae by eating...
undercooked meat containing the cysts
58
how do proglottids leave the human body after sexual reproduction?
feces
59
how do large tapeworms rob humans of nutrients and cause nutritional deficits
blocking intestines
60
animals in this phylum include oysters, clams, snails, slugs, octopi, and squids
Mollusca
61
the primary body cavity in Mollusca
hemocoel
62
the body of a mollusc has three main parts:
muscular foot, visceral mass of internal organs, and a mantle
63
what is the muscular foot of mollusca's function?
movement
64
a fold of tissue in Mollusca that drapes over the visceral mass and secretes a shell
mantle
65
a water-filled chamber that houses gills, anus, and excretory pores in Mollusca
mantle cavity
66
the straplike organ that molluscs feed by to scrape up food
radula
67
where are molluscs gonads (ovaries or testes) located?
visceral mass
68
all molluscs are _____ and most secrete a ____________ made of calcium carbonate
soft-bodied, hard protective shell
69
slugs, squids, and octopi have a reduced _____ or have lost their shell completely during their evolution
internal shell
70
the only clade of molluscs with a closed circiulatory system
Cephalopods
71
clade of molluscs that have a shell divided into two halves (scallops)
Bivalvia
72
clade of molluscs with an oval-shaped body and shell composed of eight dorsal plates
Chiton
73
clade of molluscs that move at snail speed with a spiraled shell that the animal can retreat into (land snail)
Gastropods
74
phylum meaning "little rings" referring to their bodies resembling a series of fused rings
Annelida
75
segmented worms that live in the sea, freshwater, and damp soil are in the phylum:
Annelida
76
roundworms found in aquatic habitats, soil, and plant tissue are in the phylum:
Nematoda
77
while nematodes lack a circulatory system, they have a ....
alimentary canal
78
nutrients are transported throughout nematodes body via the ...
hemocoel
79
this phylum includes species that parasitize plants and some are agricultural pests that attack crops or animals
Nematoda
80
this phylum consists of mostly insects and are regarded as the most successful of all animal phyla
Arthropods
81
arthropods are estimated to be as old as what event?
the Cambrian explosion
82
the exoskeleton of an arthropod constructed from layers of protein and the polysaccharide chitin is called the
cuticle
83
what kind of circulatory system do arthropods have, including hemolymph
open circulatory system
84
sea stars and sea urchins (slow moving sessile marine animals) belong to this phylum:
Echinodermata
85
DNA evidence shows that echinoderms are closely related to:
chordates/Chordata
86
the unique system to echinoderms; a network of hydraulic canals branching into extensions called tube feet that function in locomotion and feeding.
water vascular system
87
while echinoderms descended from bilaterally symmetrical ancestors, they seem to have what form?
radial symmetry
88
animals with a backbone
vertebrates
89
vertebrates are members of the phylum:
Chordata
90
what symmetry and clade do Chordates belong to?
bilateral symmetry; Deuterostomia
91
the longitudinal, flexible rod skeletal structure chordates are named for, and provides skeletal support:
notochord
92
four key characters of chordates include:
a notochord, a dorsal/hollow nerve cord, pharyngeal slits, and a post-anal tail
93
this develops into the CNS (brain and spinal cord) of a chordate embryo
dorsal/hollow nerve cord
94
structure of chordates that allow water entering the mouth to exit the body without passing through the entire digestive tract
pharyngeal slits
95
the structure greatly reduced in embryonic development of chordates, extending posterior to the anus
post-anal tail
96
to distinguish them from other chordates, vertebrates possess two or more sets of:
Hox genes
97
another unique feature of vertebrates is the collection of cells that appears along the edges of the closing neural tube of an embryo known as the:
neural crest
98
the most significant character of this phylum includes its name, meaning "four feet"
Tetrapods
99
the adults of living tetrapods do not have ____
gills
100
group of tetrapods whose extant members are the reptiles and mammals
amniotes
101
major derived character of amniotes that contains the amnion, the chorion, the yolk sac, and the allantois
amniotic egg
102
the part of the amniotic egg that encloses a compartment of fluid that bathes the embryo and acts as a hydraulic shock absorber
the amnion
103
in contrast to the shell-less eggs of amphibians, the amniotic egg of most reptiles and some mammals have a ____
shell
104
function of other membranes in the amniotic egg include:
gas exchange, transfer of stored nutrients to the embryo, and waste storage
105
mammals are named for their distinctive ________, which produce milk for offspring
mammary glands
106
mammals belong to a group of amniotes known as
synapsids
107
distinctive characteristic of synapsids; a hole behind the eye socket on each side of the skull
temporal fenestra
108
a group of individuals of a single species living in the same general area
population
109
the number of individuals per unit area or volume
population density
110
the pattern of spacing among individuals within the boundaries of the population
population dispersion
111
a sampling technique used by ecologists to estimate the size of animal populations
mark-recapture method
112
the influx of new individuals from other areas
immigration
113
the movement of individuals out of a population and into other locations
emigration
114
density of a population can be affected by 4 factors:
birth rate, immigration, death rate, and emigration
115
pattern of dispersion that is evenly spaced and may result from direct interactions between individuals in the population
uniform dispersion
116
pattern of dispersion that has unpredictable spacing and the position of each individual is independent of other individuals
random dispersion
117
most common pattern of dispersion in which individuals are aggregated in patches
clumped dispersion
118
the study of key characteristics of populations and how they change over time
demography
119
summarizes the survival and reproductive rates of individuals in specific age-groups within a population
life table
120
a group of individuals of the same age, from birth until all of the individuals are dead
cohort
121
a plot of the proportion or numbers in a cohort still alive at each age
survivorship curve
122
the maximum population size that a particular environment can sustain
carrying capacity
123
in this model, the per capita rate of population growth approaches zero as the population size nears the carrying capacity
logistic population growth model
124
the traits that affect an organism's schedule of reproduction and survival make up its:
life history
125
pattern in organisms that undergo a "one shot" pattern of big-bang reproduction (coho salmon)
semelparity
126
repeated reproduction pattern (female loggerhead turtle)
iteroparity
127
the number of offspring and the amount of resources a parent can devote to each offspring
trade-off
128
selection for traits that are advantageous at high densities is referred to as:
K-selection
129
selection for traits that maximize reproductive success in uncrowded environments (low densities) is called:
r-selection
130
the three traits of life history include an organism's:
development, physiology, and behavior
131
a birth rate or death rate that does not change with population density is said to be:
density independent
132
a death rate that increases with population density or a birth rate that falls with rising density is said to be:
density dependent
133
population fluctuations from year to year or place to place that are influenced by many factors and in turn affect other species
population dynamics
134
a group of spatially separated populations of one species that interact through immigration and emigration
metapopulation
135
the movement from high birth and death rates toward low birth and death rates, accompanying industrialization and improved living conditions is called
demographic transition
136
the relative number of individuals of each age in the population
age structure
137
the number of infant deaths per 1,000 live births
infant mortality
138
the predicted average length of life at birth
life expectancy at birth
139
this concept summarizes the aggregate land and water area required by each person, city, or nation to produce all the resources it consumes and to absorb all the waste it generates
ecological footprint
140
growth of a population in an ideal, unlimited environment, represented by a J-shaped curve when population size is plotted over time
exponential growth
141
population growth that levels off as population size approaches carrying capacity
logistic growth
142
the natural fluctuation of economic activity between periods of expansion and contraction
boom-and-bust cycle
143
factors such as the number of species in a community, particular species present, and relative abundance of species affect:
community structure
144
interactions such as competition, predation, herbivory, parasitism, mutualism, and commensalism are:
interspecific interactions
145
a -/- interaction that occurs when individuals of different species each use a resource that limits the survival and reproduction of both individual
competition
146
an outcome caused by a slight reproductive advantage leading to a local elimination of the inferior competitor
competitive exclusion
147
the specific set of biotic and abiotic resources that na organism uses in its environment
ecological niche
148
the differentiation of niches that enables similar species to coexist in a community
resource partitioning
149
the niche potentially occupied by a species
fundamental niche
150
the portion of a species fundamental niche that is actually occupied
realized niche
151
the tendency for characteristics to diverge more in sympatric than in allopatric populations of two species
character displacement
152
any type of +/- interaction in which individuals of one species benefit by feeding on (and harming) individuals of the other species
exploitation
153
a +/- interaction in which an individual of one species, the predator, kills and eats an individual of the other species, the prey
predation
154
animals with effective chemical defenses exhibit bright/warning coloration known as:
aposematic coloration
155
mimicry in which a palatable/harmless species mimics an unpalatable/harmful species to which it is not closely related
Batesian mimicry
156
camouflage coloration, making prey difficult to see
cryptic coloration
157
mimicry in which two or more unpalatable species resemble each other
Mullerian mimicry
158
an exploitative (+/-) interaction in which an organism (herbivore) eats parts of a plant or alga, thereby harming it but usually not killing it
Herbivory
159
a +/- exploitative interaction in which one organism (the parasite) derives its nourishment from another organism (the host), which is harmed in the process
parasitism
160
parasites that live within the body of their host
endoparasites
161
parasites that feed on the external surface of a host
ectoparasites
162
a +/+ or +/0 interaction between members of two species in which at least one individual benefits and neither is harmed
positive interaction
163
a +/+ interaction that benefits individuals of both of the interacting species
mutualism
164
an interaction that benefits the individuals of one of the interacting species but neither harms nor helps the individuals of the other species
commensalism
165
the variety of different kinds of organisms that make up the community
species diversity
166
the number of different species in the community (component of species diversity)
species richness
167
the proportion each species represents of all individuals in the community (component of species diversity)
relative abundance
168
organisms that humans have moved to regions outside of the species' native range
introduced species
169
the feeding relationships between organisms
trophic structure
170
the transfer of chemical energy from its source in plants and other autotrophs through herbivores to carnivores, and eventually to decomposers
the food chain
171
the position an organism occupies in a food chain
trophic level
172
a group of food chains that are linked together form a:
food web
173
suggests the length of a food chain is limited by the inefficiency of energy transfer along the chain
energetic hypothesis
174
this species has strong effects on their communities as a result of their large size or high abundance (trees)
foundation species
175
species not usually abundant in a community and exert strong control on community structure by their pivotal ecological roles
keystone species
176
species that create or dramatically alter their environment
ecosystem engineers
177
the abundance of organisms at each trophic level is limited by nutrient supply or the availability of food at lower trophic levels (what organisms eat)
bottom-up control
178
the abundance of organisms at each trophic level is controlled by the abundance of consumers at higher trophic levels (what eats organisms)
top-down control
179
a community's tendency to reach and maintain a relatively constant composition of species
stability
180
an event such as a storm, fire, flood, drought, or human activity that changes a community by removing organisms from it or altering resource availability
disturbance
181
model that describes most communities as constantly changing after disturbance
nonequilibrium model
182
states that moderate levels of disturbance foster greater species diversity than do high or low levels of disturbance
intermediate disturbance hypothesis
183
process in which a disturbed area may be colonized by a variety of species, which are in turn replaced by still other species
ecological succession
184
process that occurs when ecological succession begins in a virtually lifeless area
primary succession
185
process that involves the recolonization of an area after a major disturbance has removed most but not all of the organisms in a community
secondary succession
186
ecological succession is a response to disturbance of the environment, and some of the strongest disturbances result from:
human activites
187
community with only one stable equilibrium
climax community
188
the rate of evaporation of water from soil and plants
evapotranspiration
189
pattern of species suggesting that the larger the geographic area of a community, the more species it has
species-area curve
190
model in which an equilibrium will eventually be reached where the rate of species immigration equals the rate of species extinction
island equilibrium model
191
disease-causing microorganisms, viruses, viroids, or prions
pathogens
192
pathogens that are transferred to humans from other animals, either through direct contact with an infected animal or via an intermediate species
zoonotic pathogens
193
an organisms that transmits pathogens from one host to another
vector
194
the sum of all the organisms living in a given area and the abiotic factors with which they interact
ecosystem
195
the two emergent properties of an ecosystem include:
energy flow and chemical cycling
196
in an ecosystem, energy enters ecosystems as sunlight and is converted to chemical energy by autotrophs, passed to heterotrophs through food, and dissipated as heat
energy flow
197
in an ecosystem, elements such as carbon and nitrogen are passed between the biotic and abiotic components of the ecosystem
chemical cycling
198
the first law of thermodynamics (law of conservation of mass):
energy cannot be created or destroyed but only transferred or transformed
199
the second law of thermodynamics:
every exchange of energy increases the entropy of the universe
200
autotrophs or an ecosystem are also referred to as
primary producers
201
herbivores of an ecosystem are also referred to as
primary consumers
202
carnivores that eat herbivores of an ecosystem are also referred to as
secondary consumers
203
carnivores that eat other carnivores of an ecosystem are also referred to as
tertiary consumers
204
consumers of an ecosystem that get their energy from detritus are also referred to as
decomposers
205
nonliving organic material (feces, dead organisms, fallen leaves)
detritus
206
the third law of thernodynamics:
entropy of a perfect crystal at absolute zero (0 Kelvin) is zero
207
the amount of light energy converted to chemical energy by autotrophs during a given time period in an ecosystem:
primary production
208
the amount of energy from light (or chemicals in chemoautotrophic systems) converted to the chemical energy of organic molecules per unit time
gross primary production (GPP)
209
gross primary production minus the energy used by the primary producers (autotrophs) for their cellular respiration
net primary production (NPP)
210
the measure of the biomass accumulation by producers and consumers during that time
net ecosystem production (NEP)
211
the element that must be added for production to increase
limiting nutrient
212
process that occurs when the nutrient status of an ecosystem changes from nutrient-poor to nutrient-rich
eutrophication
213
regions in which oxygen concentrations drop to levels that are fatal to many organisms
dead zones
214
the amount of chemical energy in consumers' food that is converted to their own new biomass during a given period
secondary production
215
the percentage of energy stored in assimilated food that is used for growth and reproduction, not respiration
production efficiency
216
the percentage of production transferred from one trophic level to the next
trophic efficiency
217
net productions of different trophic levels are arranged in tiers to show the loss of energy (expressed in joules) with each transfer in a food chain in this model:
energy pyramid
218
model in which each tier represents the total dry mass of all organisms in one trophic level; a consequence of low trophic efficiency
biomass pyramid
219
because nutrient cycles involve both biotic and abiotic components, they are called:
biogeochemical cycles
220
two general scales of biogeochemical cycles are:
global and local
221
strategy that uses organisms to detoxify polluted ecosystems and remove harmful substances from an ecosystem
bioremediation
222
strategy that uses organisms to add essential materials to a degraded ecosystem
biological augmentation
223
The earliest ancestors of about half of all extant animal phyla can be traced back to the __________ explosion.
Cambrian
224
Gastrulation is the process that directly forms the __________.
germ layers
225
Which of the following is radially symmetrical?
A donut
226
Each of the following statements describes characteristics of animals except for one. Which statement about animals is incorrect?
they ingest their food
they have tissues, organs, and organ systems
they are eukaryotes
they are heterotrophic
they are all multicellular
they have tissues, organs, and organ systems
227
An important trend in animal evolution was cephalization, or development of a "head". An animal is said to show cephalization when it __________.
has an aggregation of sensory structures at one end of the body
228
Which of the following animals does NOT have a body cavity?
mouse
flatworm
clam
nematode
earthworm
flatworm
229
During embryological development, the anus forms before the mouth in __________.
Chordates
230
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?
Look for cell walls under a microscope.
231
All animals can trace their lineage to a common ancestor that lived in the _____.
Neoproterozoic era
232
The animal phylum most like the protists that gave rise to the animal kingdom is __________.
Porifera
233
Which of the following is a characteristic of cnidarians?
bilateral symmetry
gastrovascular cavity
mesoderm
anus
radula
gastrovascular cavity
234
Which of the following statements correctly describes a characteristic of the phylum Platyhelminthes?
They typically reproduce asexually.
They are diploblastic.
They are all parasitic.
They are dorsoventrally flattened.
They are radially symmetrical.
They are dorsoventrally flattened.
235
Members of the phylum Mollusca __________.
are filter feeders
have tentacles surrounding a central mouth/anus
are soft-bodied and often covered by a shell
have segmented bodies and paired, jointed appendages
have closed circulatory systems
are soft-bodied and often covered by a shell
236
Which of the following statements is true of annelids?
They have pseudocoeloms.
They have a gastrovascular cavity.
They have a nerve net.
They perform gas exchange across their skin.
They have an open circulatory system.
They perform gas exchange across their skin.
237
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 description, it may be determined that the animal must be a(n) __________.
annelid
238
Which of the following are thought to be most closely related to humans?
sea stars
snails
ants
earthworms
jellies
sea stars
239
Which of the following combinations of phylum and description is correct?
Porifera −
gastrovascular cavity, coelom
Nematoda −
roundworms, internal skeleton
Echinodermata −
radial symmetry as a larva, coelom
Platyhelminthes −
flatworms, gastrovascular cavity, no body cavity
Platyhelminthes −
flatworms, gastrovascular cavity, no body cavity
240
What evidence suggests that vertebrates are more closely related to echinoderms than are any other invertebrate phyla?
Shared patterns of development
Shared morphology
Shared DNA sequences
Shared DNA sequences
241
Jaws evolved __________.
by modification of the skeletal rods that previously supported the anterior pharyngeal slits
from the bony armor in ancient jawless fish
by modification of middle ear bones
from the rasping tongue
from arthropod jaws
by modification of the skeletal rods that previously supported the anterior pharyngeal slits
242
The diagnostic feature of Chondrichthyes is __________.
a swim bladder
an endoskeleton of cartilage
jaws
a lateral line system
a streamlined, torpedo-shaped bod
an endoskeleton of cartilage
243
fossils that have features that are intermediate between ancestors and descendants
transitional fossil
244
The following are examples of...
a bird
a reptile
a mammal
an amphibian
Tetrapods
245
What kind of habitat did tiktaalik live in?
Tiktaalik lived in a warm, freshwater swamp.
Tiktaalik lived in cold, artic tundra.
Tiktaalik lived in a shallow, marine environment.
Tiktaalik lived on dry, rocky slopes.
Tiktaalik lived in a warm, freshwater swamp.
246
Tiktaalik had a combination of fishlike and tetrapod-like characteristics. Which were the tetrapod-like characteristics?
Select all that apply.
scales
fins with fin rays
a neck
flat head with eyes on top
interlocking ribs
a neck
flat head with eyes on top
interlocking ribs
247
How did the great transition from fish to tetrapod occur?
The transition occurred gradually over time, so there are many intermediate forms.
248
Which discovery ultimately overturned the prevailing perception that all dinosaurs were large, slow, and lumbering?
the small theropod dinosaur Deinonychus, which had a large sickle-shaped claw on each of its hind limbs
249
A key characteristic of modern birds is flight powered by feathered wings. What evidence supports the hypothesis that the first feathers served a purpose other than flight?
some feathered theropods were not capable of flight
250
There are three major groups of mammals, categorized on the basis of their _____.
method of reproduction
251
What primate group is most closely related to humans?
apes
252
_____ are the oldest known primate group.
Prosimians
253
The primates that spend the most time walking upright are the _____.
hominids
254
What anthropoid group consists of primates who are mostly tree dwellers and whose forelimbs and hind limbs are about equal in length?
monkeys
255
What primate group lives in trees in Central and South America and have nostrils that are wide open and far apart?
New World monkeys
256
What statement supports the conclusion that the common ancestor of modern chimps and modern humans lived around 7 million years ago?
Analysis of modern human and modern chimpanzee protein and DNA sequences suggests that their lineages diverged about 7 million years ago.
257
What anatomical feature of the 3.2-million-year-old Australopithecus fossil known as "Lucy" suggest she was a bipedal hominid?
a much shorter hip bone that is broader from front to back and wraps around the side
258
In wild populations, individuals most often show a __________ pattern of dispersion.
clumped
259
In the models that describe population growth, r stands for __________.
per capita population growth rate
260
The number of individuals that a particular habitat can support with no degradation of that habitat is called __________.
carrying capacity
261
What condition favors "big-bang" reproduction?
low rates of offspring survival
262
What is regarded as a density-independent factor in the growth of natural populations?
flooding
263
Resource competition, territoriality, disease, and toxic wastes are some of the factors that provide __________ and help regulate population.
negative feedback
264
A broad-based, pyramid-shaped age structure is characteristic of a population that is __________.
growing rapidly
265
What is the most accurate statement on Earth's carrying capacity for humans?
Our technology has allowed the human population to keep increasing K.
266
According to the principle of competitive exclusion, two species cannot continue to occupy the same _____.
ecological niche
267
Caribbean coral reef communities have been strongly influenced by an unknown pathogen that causes white-band disease. How can the effect of white-band disease best be described?
a cascade event that shifts the entire makeup of the community
268
The term used to describe a harmless organism resembling a harmful one is __________.
Batesian mimicry
269
Which of the following examples best illustrates ecological succession?
Grass grows on a sand dune, is replaced by shrubs, and then by trees.
270
Cellulose-digesting microorganisms live in the guts of termites and ruminant mammals. The microorganisms have a home and food, and their hosts gain more nutrition from their meals. This relationship is an example of _____.
mutualism
271
An organism's trophic level refers to __________.
An organism's trophic level refers to __________.
View Available Hint(s)for Part A
its position in the food chain
272
According to MacArthur and Wilson's Island Equilibrium Model, species immigration and extinction rates on a particular island correlate to __________.
the island's size and distance from the mainland
273
Keystone species are those species __________.
whose absence would result in a decrease in species diversity in a community
274
The energy for nearly every organism in nearly every ecosystem ultimately comes from __________.
the sun
275
On a global scale, energy __________ ecosystems whereas chemical elements __________ ecosystems.
flows through, are recycled in
276
Consider this segment of a food web: snails and grasshoppers eat pepper plants; spiders eat grasshoppers; shrews eat snails and spiders; owls eat shrews. The shrew occupies the trophic level(s) of __________.
secondary and tertiary consumers
277
The relationship between biomass and primary productivity is that _____.
primary productivity is the rate at which biomass is produced
278
What statements correctly explains why a diagram of energy flow from trophic level to trophic level is shaped like a pyramid?
Most energy at each level is lost, leaving little for the next.
279
An ecosystem is unlikely to be limited by the supply of _____ because it is obtained from the air.
carbon
280
Biogeochemical cycles are crucial to ecosystem function because __________.
nutrients and other life-sustaining molecules are in limited supply and must be continually recycled
