New Science Section 2 Flashcards
1
Q
What is community ecology?
A
how populations grow, disperse, and interact with each other
2
Q
What are ecosystems?
A
the integration of living and nonliving components in specific geographic areas
3
Q
What are biomes?
A
geographic regions distinguished by different dominant forms of plants and animals
4
Q
What causes biomes to be distinct from each other?
A
variation in global patterns of temperature, sunlight, and rainfall
5
Q
What is the most common measure of biological diversity?
A
the number of different species in an area
6
Q
The number of different species in an area is the most common measure of __________ ____________.
A
biological diversity
7
Q
What is the great number of species on Earth the result of?
A
a large amount of genetic diversity
8
Q
What is genetic diversity?
A
the diversity/variety of genes
9
Q
What are genes?
A
the chemical building blocks that provide the blueprint for how every organism develops
10
Q
Genes are the chemical building blocks that provide the ________ for how every organism develops.
A
blueprint
11
Q
How many different genes do humans have?
A
30,000
12
Q
What is the only exception to the rule that no 2 people have the same genes?
A
identical twins
13
Q
What are species distinguished by at the most basic level?
A
how different their genes are
14
Q
What is the ultimate source of biodiversity on Earth?
A
genetic diversity
15
Q
What is a change in genetic blueprint over many generations a result of?
A
evolution
16
Q
Where do all organisms inherit their genes from?
A
their parent(s)
17
Q
What are more complex traits, like body size, a result of?
A
the interaction between more than one gene
18
Q
What do genes contain the instructions for?
A
relatively simple traits
19
Q
What is a phenotype?
A
an organism’s physical traits that are a result of the genotype
20
Q
What is a genotype?
A
all of an organism’s genes
21
Q
The genotype is the code for an organism’s ______________.
A
phenotype
22
Q
What are genes chemically made up of?
A
DNA
23
Q
What are genes arranged on?
A
chromosomes
24
Q
What are chromosomes?
A
structures within an organism’s cells that house genes
25
What is the name of the alternate form of a gene?
allele
26
In pea plants, what phenotype does the BB produce?
purple flowers
27
In pea plants, what phenotype does bb produce?
white flowers
28
In pea plants, what phenotype does Bb produce?
purple flowers
29
In pea plants, what is the genotype for purple flowers?
BB or Bb
30
In pea plants, what is the genotype for white flowers?
bb
31
Is it possible to estimate the number of different alleles for genes of all individuals in a population?
No, it is impossible
32
What is Canis familiaris?
the domestic dog
33
What is the only way a new allele can be produced?
through a mutation
34
What is a genetic mutation?
an error made when genetic material is copied
35
When do mutations occur?
randomly and spontaneously, but can occur more often when exposed to anthropogenic chemicals
36
Mutations are more likely to occur with exposure to what?
anthropogenic chemicals, like those in tobacco smoke or radiation
37
Where do most neutral or harmful mutations die?
within the organism
38
How can a mutation survive and appear in the next generation?
it must appear in the sex cells
39
How can a mutation be beneficial to an organism?
if it makes it more likely the organism will survive and reproduce
40
If there are many different alleles for genes in a population, will there be a lot of genetic variation?
Yes
41
Why do larger populations usually have more genetic variation than smaller populations?
because more individuals means a higher likelihood the population will have more alleles
42
What is required for more complex traits?
the interaction between the genotype and its environment
43
What is the formula for phenotype?
Phenotype = Genotype + Environment
44
Species diversity results from what processes?
adaptive and nonadaptive processes
45
How do most new species arise?
when the genotypes and phenotypes of two or more populations diverge through processes at the population level
46
How does a frog have longer legs benefit the organism?
it allows it to hop faster, making it able to catch food and escape predators easier
47
How do beneficial traits get established in a population?
organisms with these traits are more likely to reproduce than ones without, allowing for more organisms with the traits
48
What is fitness a measure of?
relative viability and fertility of an organism
49
What is viability?
ability to survive
50
What is fertility?
reproductive success
51
What can the successful survival of the genes of more fit individuals over many generations lead to?
a change in the average phenotype
52
What type of disease is sickle-cell disease?
a genetic disease
53
What is sickle-cell disease?
a genetic disease that reduces the oxygen-carrying capacity of blood
54
What does sickle-cell disease usually result in?
many severe mental and physical impairments, often leading to death
55
Sickle-cell disease occurs in people of what descent?
African descent
56
What is a benefit of sickle-cell disease?
it conveys natural resistance to malaria
57
What is one of the most deadly diseases in Africa?
malaria
58
How many copies of the allele are necessary to produce sickle-cell disease?
2
59
What happens if individuals only carry 1 copy of the allele for sickle-cell disease?
they will receive natural resistance to malaria, but will not develop the disease
60
What is the theory as to why sickle-cell disease has persisted?
because if an organism has 1 copy, it is benefitted because of resistance to malaria
61
What is sickle-cell disease an example of?
harmful alleles
62
What did Charles Darwin do with the concept of natural selection?
he synthesized it into a unifying theory
63
Who synthesized the concept of natural selection into a unifying theory?
Charles Darwin
64
Darwin made many observations about phenotypic variation and fitness when abroad what ship?
the HMS Beagle
65
What did Darwin do on the HMS Beagle?
he made observations about fitness and phenotypic variation among species
66
When did Darwin publish his natural selection theory?
1859
67
What did Darwin call his natural selection theory when he published it in 1859?
The Origin of Species by Means of Natural Selection
68
What are the key ideas of Darwin's natural selection theory?
1. Organisms produce more offspring than needed to replace the parents
2. Individuals will have many phenotypes
3. Some phenotypes will make an organism more fit
4. More fit individuals will be selected and well-established over time
69
What does Darwin's natural selection theory explain?
why individuals with certain traits survive and reproduce
70
What is the process of becoming more fit or most suited for an environment?
adaptation
71
What type of adaptation is a human sweating or a dog panting?
physiological/behavioral adaptation
72
How can many organisms adapt quickly?
by changing their physiological or behavioral responses
73
What will happen to a species as its environment goes through major changes over a long period of time?
it will go extinct or adapt through natural selection
74
What do thick, fleshy leaves with waxy surfaces help a plant do?
conserve water
75
What does the ability of a species to adapt to environmental changes depend on?
how much and how fast the change occurs
76
Much of the current environmental change caused by humans is ___________ and ____________.
dramatic, sudden
77
When individuals from one population migrate to and disperse with another population, what occurs?
gene flow
78
High rates of gene flow occur in species with what?
much dispersal of individuals
79
What is genetic isolation of species an issue in?
the maintenance of biodiversity
80
What type of process is gene flow?
a nonadaptive process
81
What type of process is genetic drift?
a nonadaptive process
82
What is genetic drift?
random changes in genotypes among small populations
83
Genetic drift is known to be an important mechanism in __________.
evolution
84
What is the bottleneck effect?
a drastic reduction in population size due to hunting, habitat loss, a natural disaster, or other changes in the environment
85
What causes the bottleneck effect?
hunting, habitat loss, natural disasters, and other changes to the environment
86
What is low genetic variation correlated to?
many problems, including increased risk of disease and low fertility
87
What happens to the number of different alleles when the bottleneck effect occurs?
it decreases
88
How is genetic diversity affected by the bottleneck effect?
genetic diversity drastically decrease
89
What is a well-known example of a species that has undergone the bottleneck effect?
the cheetah
90
What caused the drastic reduction of the cheetah population?
hunting and habitat loss
91
Why does the cheetah population lack genetic variation?
because there are so few cheetahs
92
The genetic variation in the cheetah is so low all cheetahs are considered what?
identical twins
93
Cheetahs tend to have ____ fertility and _______ rates of disease.
low, high
94
What percent of male cheetahs have abnormal sperm cells?
0.7
95
In what cheetahs have reliable studies been conducted?
zoo cheetahs
96
Do we know if wild cheetahs have the same reduced fitness as zoo cheetahs?
No, because no reliable studies have been conducted on them yet
97
How long does a significant change in a species' genotype take?
hundreds to thousands of years
98
Do smaller-scale evolutionary changes over a shorter or longer time scale?
shorter
99
What 3 factors influence the pace of evolution by natural selection?
rate of environmental change, amount of genetic variation in a population, and how fast traits can spread within a population
100
What does rapid environmental change force a population to do?
evolve quickly to adapt or die out
101
Do adaptive traits spread faster in large or small populations?
small populations
102
Small populations are more likely to undergo evolution by what processes?
nonadaptive processes, like genetic drift and bottlenecks
103
How many years ago was the Big Bang?
14 billion years ago
104
How many years ago was Earth created?
4.5 billion years ago
105
How many years ago did prokaryotes appear on the Fossil Record?
3.8 billion years ago
106
How many years ago did eukaryotes appear on the Fossil Record?
2 billion years ago
107
How many years ago did Protozoa appear on the Fossil Record?
1.5 billion years ago
108
How many years ago did Cyanobacteria appear on the Fossil Record?
2 billion years ago
109
How many years ago did plants appear on the Fossil Record?
600 million years ago
110
How many years ago did sponges and corals appear on the Fossil Record?
500 million years ago
111
How many years ago did fish appear on the Fossil Record?
420 million years ago
112
How many years ago did amphibians appear on the Fossil Record?
400 million years ago
113
How many years ago did reptiles appear on the Fossil Record?
300 million years ago
114
How many years ago did mammals appear on the Fossil Record?
178 million years ago
115
How many years ago did birds appear on the Fossil Record?
65 million years ago
116
How many years ago did primates appear on the Fossil Record?
55 million years ago
117
What does the number of species on Earth equal?
all the species that have existed on Earth minus the species that have gone extinct
118
If the environment changes so that a population is no longer adapted to it, what happens to its growth rate?
its growth rate becomes negative
119
What happens to organisms that can't adapt to environmental change?
they will go extinct
120
What is most of what we know about the evolution of life based on?
fossils
121
What are fossils?
prehistoric remains of plants and animals preserved in rock
122
How do fossils form?
their dead body gets buried and compacted by sediment, eventually becoming hard, rock-like material, a fossil
123
Where are the oldest fossils found?
at the deepest layers
124
What is the basis of the geologic time scale?
the fossil record
125
What does the geologic time scale divide time into?
various intervals
126
When did multicellular and shelled organisms appear in the fossil record?
540 million years ago
127
When can we trace identifiable species?
1-10 million years ago
128
Do organisms in the fossil record usually exist today?
No
129
What is an example of an organism in the fossil record that still exists today?
the ginkgo tree
130
Where does the ginkgo tree exist?
China and the US
131
What is the ginkgo tree in the US?
an ornamental tree
132
When did the ginkgo tree appear in the fossil record?
60 million years ago
133
What happens during periods of mass extinction?
large amounts of species die in a short time interval
134
When did the greatest mass extinction event occur?
the end of the Paleozoic era
135
What percent of marine species went extinct at the end of the Paleozoic era?
90-95%
136
What percent of land vertebrates went extinct at the end of the Paleozoic era?
0.7
137
What caused the mass extinction at the end of the Paleozoic era?
a shutdown of ocean circulation with a huge, sustained volcanic eruption
138
What is the boundary of the Cretaceous and Tertiary Periods known as?
the K-T Boundary
139
When did the mass extinction event during the K-T Boundary occur?
65 million years ago
140
What species in particular went extinct during the K-T Boundary?
the dinosaurs
141
How long did the recovery of previous mass extinctions take?
10-100 million years
142
How can humans affect biodiversity? (what ways)
directly and indirectly
143
How did humans contribute to the extinction of the Dodo bird?
they overhunted them and introduced species that competed with them for food
144
In what century did humans exterminate the Dodo?
17th century
145
Where did the Dodo used to live?
the Indian Ocean island of Mauritius
146
Why did humans hunt the Dodo so much?
because they were an easy source of meat
147
What were Dodo birds?
large, flightless birds
148
What is habitat fragmentation?
the splitting up of land into smaller pieces
149
What causes habitat fragmentation?
construction of roads, housing, industrial centers, and more
150
What does habitat fragmentation reduce?
the area of contiguous habitat
151
What can reducing the area of contiguous habitat cause?
barriers to be created, which affect the normal movement of a species for things like feeding, mating, and migrating
152
What type of land do mountain lions, wolves, and tigers need?
large tracts of relatively uninhabited and undisturbed land
153
Fragmentation generates more habitat along an _______.
edge
154
What effects does increased edge habitat have on species composition?
it can change the species composition of the habitat overall
155
How does habitat fragmentation affect population size?
it can divide a population into several smaller population
156
What happens to the populations that have been split up due to habitat fragmentation?
they become isolated and lose genetic variation through genetic drift
157
What are species that are not native to an area but are introduced deliberately or accidentally?
exotic species
158
What are exotic species?
species that are not native to an area but are introduced deliberately or accidentally
159
In the process of moving people and their belongings to other places, what have we transported?
many species and diseases
160
Where is the zebra mussel native?
the Capsian Sea in Asia
161
Where did the zebra mussel enter North America?
the Great Lakes
162
When did the zebra mussel first enter the Great Lakes? (decade)
1980s
163
How did the zebra mussel get transported to North America?
through the ballast water in ships that accidentally had zebra mussels inside of it
164
How has the zebra mussel population grown in North America?
exponentially
165
Where in North America is the zebra mussel prominent?
Eastern US and Canada
166
Does the zebra mussel have predators in North America?
No
167
What negative impacts has the zebra mussel had?
it has depleted food supplies, clogged water intake valves, and caused many other problems
168
When an exotic species enters a new environment, what may it encounter?
an unexploited resource it can rapidly utilize
169
Why is it hard to keep the populations of exotic species under control?
because their natural predators are not present in their new environment
170
What provides the first step in understanding why some species are found or not found in various places?
evolutionary history
171
Species distribution and abundance being limited by environmental conditions is in the domain of __________.
ecology
172
What is ecology?
the study of the relationship between organisms and their environment
173
Ecologists have divided the field of ecology into what?
a hierarchy, from individuals to large-scale ecological systems
174
What are the 3 most critical factors to an individual's ability to survive in an environment?
the abiotic conditions, availability of resources, and a habitat for the individual to live in
175
What are conditions?
chemical or physical factors in an environment that influence growth and survival
176
What do conditions influence?
the growth and survival of an organism
177
What do conditions determine?
which species flourish in particular habitats and not others
178
What conditions determine the absence or presence of species in terrestrial systems?
availability of light, temperature, precipitation, soil type, and amount of nutrients
179
Conditions in terrestrial systems vary depending on what?
latitude and elevation
180
What conditions determine the absence or presence of species in aquatic systems?
temperature, availability of light, amount of oxygen, salinity, and acidity
181
Conditions in aquatic systems vary depending on what?
location in the stream (upstream, midstream, downstream), latitude, and elevation
182
What are the locations in a stream?
upstream, midstream, and downstream
183
How will a species live under optimal conditions?
the species will thrive, meaning they will survive, grow, and reproduce
184
What does it mean for a species to thrive?
it means they will survive, grow, and reproduce
185
How will a species live under less optimal conditions?
they will survive and might grow, but will not reproduce
186
How will a species live under even worse optimal conditions? (will still survive)
they will survive, but won't grow or reproduce
187
What is the range where a species can exist?
the range of tolerance
188
What is a resource?
an aspect of the environment used to stay alive
189
What is an aspect of the environment used to stay alive?
a resource
190
Is light a resource or condition?
resource
191
Is weather a resource or condition?
condition
192
Is temperature a resource or condition?
condition
193
Is oxygen a resource or condition?
resource
194
What is the difference between resources and conditions?
resources can be consumed and thus become unavailable to organisms, unlike conditions
195
The amount of available resources is important to which levels of ecology?
all levels of ecology
196
Why do individuals require sufficient resources?
to grow and reproduce
197
Why do populations require sufficient resources?
to maintain a size that prevents extinction
198
Why do communities require sufficient resources?
to maintain several species in a single habitat
199
Can habitats with a large amount of resources maintain a little or a lot of individuals?
a lot of individuals
200
What is the direct correlation between the amount of resources and the number of species in a habitat?
there is very little direct correlation
201
Why is there very little direct correlation between the amount of resources and the number of species in a habitat?
it depends on the varied abilities of the organisms to use the resources under the abiotic conditions
202
What is an example of a habitat with a lot of resources but very harsh abiotic conditions?
salt marshes
203
Where do the salt marshes on the Eastern coast of the US extend?
from Georgia to Cape Cod
204
Salt marshes act like a(n) ____________ ________ for nutrients caught from the flow of rivers.
storage tank
205
How are the nutrient and biomass levels of a salt marsh?
both are very high
206
What are salt marshes important feeding nurseries for?
fish and shellfish
207
How is the diversity of a salt marsh?
extremely low
208
In salt marshes, usually only a few grass species make up what percent of the total biomass?
over 95%
209
Why do only a few grass species dominate over 95% of a typical salt marsh?
because they are one of the few who are adapted to the harsh abiotic conditions of the habitat
210
What are the extreme abiotic conditions of a salt marsh?
rapid increase and decrease of salt concentrations, low oxygen levels in the soil, and large amounts of toxins
211
What causes the rapid increase of salt concentrations in salt marshes?
rapid evaporation
212
What do summer low tides and rapid evaporation cause in a salt marsh?
an increase in salt concentrations
213
What do flooding or heavy rains cause in a salt marsh?
a decrease in salt concentrations
214
What usually causes a rapid decrease in salt concentrations in salt marshes?
flooding or heavy rains
215
What causes the low-oxygen soils in a salt marsh?
a high level of microbial decomposition
216
Besides low-oxygen levels in the soil, what else does the high level of microbial decomposition in a salt marsh cause?
large amounts of toxins
217
What adaptations allow salt marsh grasses to survive in the harsh conditions of salt marshes?
special tissues to concentrate and excrete salt, air chambers in their roots, and changing the way they allocate their energy
218
What do air chambers in the roots of salt marsh grasses allow them to do?
create their own oxygen-rich microhabitats
219
What do the special tissues in salt marsh grasses allow them to do?
concentrate and excrete salt when needed
220
What are the 3 ways populations of different interact?
interspecific competition, predation, and mutualism
221
When does interspecific competition occur?
when individuals of different species share a limiting resource in the same area
222
What is a limiting resource?
one the population depends on but exists in low
223
What occurs when individuals of different species share a limiting resource in the same area?
interspecific competition
224
What happens as the limiting resource decreases?
the population(s) that depend(s) on it decreases as well
225
On what condition can populations share food sources?
if that food source is not a limiting resource
226
Can populations share their limiting resource?
No
227
If a resource limits the growth and reproduction of a species, it can't be shared. What is this known as?
competitive exclusion
228
What is the competitive exclusion principle?
If a resource limits the growth and reproduction of a species, it can't be shared; one species will succeed and the other will die out.
229
Where is the wild oat commonly found?
the Great Plains of North America
230
What does the wild oat compete with?
agricultural crops
231
What does the wild oat compete with agricultural crops for?
space and resources
232
How do wild oats outcompete crop plants?
their seeds ripen earlier, allow for them to start growing before other plants
233
What is the competitive exclusion principle very closely related to?
the concept of niche
234
What is niche often confused?
habitat
235
What is a habitat?
the range of environments in which a species occurs
236
What is niche in the context of ecology?
the role of an organism within a community
237
What do many ecologists rephrase the competitive exclusion principle as?
two populations that fill the same niche cannot coexist
238
What is the only exception to the competitive exclusion principle?
if their niches do not overlap completely
239
What are the types of predation?
carnivory, herbivory, and parasitism
240
What is predation?
the use of one species as a resource by another
241
This definition of predation, the use of one species as a resource by another, allows for what other types of species interactions that aren't carnivory?
herbivory and parasitism
242
What type of consumer animal is a wolf?
carnivore
243
What type of consumer animal is a lion?
carnivore
244
What is herbivory?
eating only plants, seeds, fruits, or other types of autotrophs
245
What is parasitism?
using another organism as a habitat, causing injury but usually not death
246
What does parasitism typically cause to the organism being used as the habitat?
injury, but usually not death
247
What is predation an important cause of?
natural selection and evolution
248
What establishes how energy flows in an ecosystem?
predation
249
How do predators limit the growth of their prey populations?
by consuming them and changing their behavior
250
How do most predator-prey cycles end in the lab?
with the prey going extinct and then the predator
251
What do mutualistic interactions do to survival probability and reproduction?
they increase both for both species involved
252
What do ecologists see mutualism as?
reciprocal exploitation
253
How is mutualism seen as reciprocal exploitation?
since each species is using the other for self-benefit
254
What happens to a mutualistic interaction if self-benefit to one population becomes too low?
the interaction will be stopped as it is no longer of value
255
What is the most common type of mutualism?
the interaction between plants and their pollinators
256
What is the most important type of mutualism?
the interaction between plants and their pollinators
257
What do many plant species depend on pollinators for?
their reproduction and survival
258
How is the mutualistic interaction when many pollinators pollinate a lot of plants, and/or many plants are pollinated by many pollinators?
the interaction between each plant and pollinator is weak
259
How is the mutualistic interaction when only one plant is pollinated by one pollinator, and that pollinator only pollinates that plant?
the interaction between the plant and pollinator is strong, also known as symbiotic mutualism
260
What is symbiotic mutualism?
when the mutualistic interaction is very strong
261
About how many species of fig tree are there?
900
262
Almost every fig tree of the 900 is pollinated by what?
a fig wasp
263
What causes symbiotic mutualism?
resource partitioning in the evolutionary past
264
What is a community?
any assemblage of populations in a particular area
265
What does a food web summarize?
the species that make up a community and how they are linked by energy flow
266
What is the largest fish in a lake?
tarpons
267
What are the feeding positions in a food chain or web?
trophic levels
268
What does the word trophic come from?
trophe
269
The word trophic comes from a word from which language?
Greek
270
The word trophic comes from the Greek word for what?
nourishment
271
What is the lowest trophic level?
the primary producers
272
What trophic level is a plant?
primary producer
273
What trophic level is algae?
primary producer
274
What do primary producers use to create food?
photosynthesis
275
What occurs in photosynthesis?
organisms create their food using sunlight, CO2, and water
276
Do primary producers rely on other organisms for nutrition?
No
277
What are the trophic levels higher than the primary producers?
consumers
278
Do consumers rely on other organisms for nutrition?
Yes
279
What trophic level do primary consumers feed on?
primary producers
280
What trophic level do secondary consumers feed on?
primary consumer
281
What trophic level do tertiary consumers feed on?
secondary consumer
282
What is often used to show the amount of energy transferred between different trophic levels?
an ecological pyramid
283
What percent of energy is transferred from the Sun to the primary producer?
0.01
284
What percent of energy is passed along between consumers?
0.1
285
What is the rest of the energy transferred between organisms lost as?
heat
286
What percent of energy is lost between each organism in a food web?
0.9
287
How do available energy and biomass change as we go up the ecological pyramid?
both decrease
288
What trophic level has the most biomass?
the primary consumers
289
What trophic level has the least biomass?
the quaternary consumers
290
What is the highest trophic level?
the quaternary consumer
291
What percent of energy is transferred from the primary producers to the secondary consumers?
0.01
292
What percent of energy is transferred from the primary producers to the tertiary consumers?
0.001
293
What percent of energy is transferred from the primary producers to the quaternary consumers?
0.0001
294
What is a keystone species?
a species that plays an important role in the community that is more than its relative abundance would suggest
295
What is a species that plays an important role in the community that is more than its relative abundance would suggest?
a keystone species
296
Why was the keystone species concept developed?
to explain the effect of removing a relatively rare species from a community
297
What are the 3 types of keystone species?
predators, ecosystem engineers, and mutualists
298
How are predators a keystone species?
by controlling the population of their prey
299
What type of keystone species is the sea otter?
predator
300
How are sea otters a keystone species?
by keeping the populations of urchins and kelp under control
301
How are ecosystem engineers a keystone species?
by creating and maintaining habitats for other species
302
What type of keystone species is the North American beaver?
an ecosystem engineer
303
How are beavers ecosystem engineers?
by transforming streams into ponds, creating new habitats for pond animals and plants
304
What type of keystone species is mycorrhizal fungi?
mutualist
305
How are mycorrhizal fungi mutualists?
they help trees extract nutrients, allowing for resources and habitats for other members of the forest community
306
Where do mycorrhizal fungi typically habitat/live?
on tree roots
307
How do mycorrhizal fungi help trees?
by increasing the tree's ability to extract nutrients from the soil
308
What is an ecosystem boundary?
where is starts and where it ends
309
What types of ecosystems have boundaries that are relatively easy to identify?
aquatic ecosystems
310
What is usually the boundary of an aquatic ecosystem?
where the water ends and the land starts
311
Is determining the boundary of most ecosystems hard?
Yes
312
How do environmental scientists usually estimate the boundary of terrestrial ecosystems?
by the range of populations that make up the community or by ecological processes
313
How do energy pyramids look from ecosystem to ecosystem?
relatively constant
314
How do biomass pyramids look from ecosystem to ecosystem?
they vary
315
What do biomass pyramids depend on?
characteristics of the populations that make up the trophic levels, and the physical and chemical structure of the ecosystem
316
What are the types of ecosystem-level changes?
perturbations and disturbances
317
What is a disturbance in an ecosystem?
when physical, chemical, and some biological agents cause rapid injury or death of organisms, and damage to the biotic component
318
The slow invasion of a lake by a species is what type of ecosystem change?
a perturbation
319
What is a perturbation?
any kind of change to the normal or balance in a system
320
The increase in temperature by approximately 1 °C is categorized as what type of change?
a perturbation
321
The increase in temperature by approximately 2 °C is categorized as what type of change?
a disturbance
322
What is resilience?
the rate at which an ecosystem returns to its original state after a disturbance
323
How fast does a highly resilient ecosystem return to its original state?
very fast
324
How fast does a less resilient ecosystem return to its original state?
very slow
325
If a severe drought were to eliminate half the species in a highly resilient ecosystem, how fast would it return to its original state? (years)
all the species would return the following year
326
If a severe drought were to eliminate half the species in a less resilient ecosystem, how fast would it return to its original state? (years)
the species may take several years to return, if ever
327
How many terrestrial biomes are there?
10
328
What is the wettest and warmest biome?
the tropical rainforest
329
What biome is the Amazon?
tropical rainforest
330
How is plant and animal diversity in the tropical rainforest biome?
both are high
331
How is ecosystem productivity in the tropical rainforest biome?
high
332
Where are much of the energy and nutrients of the tropical rainforest tied up in?
the vegetation
333
How are the mineral nutrients in the soil of tropical rainforests?
they are extremely poor
334
Is the tropical dry forest seasonal or year-round?
seasonal
335
Where does the tropical dry forest biome commonly occur?
the tropics
336
What tree type is common in the tropical dry forest biome?
deciduous trees
337
What do deciduous trees do during the dry season?
they drop their leaves and flowers
338
How do productivity and diversity of plant and animal species per meter of the tropical dry forest compare to tropical rainforests?
both are less
339
What biome is found in the US Pacific Northwest?
the temperate rainforest
340
What is the dominant tree type of the temperate rainforest?
tall coniferous trees
341
What factors create optimal conditions for tall trees in the temperate rainforest?
mild winters, heavy rain, and frequent fog
342
How are winters in the temperate rainforest?
mild
343
How is rain in the temperate rainforest?
heavy
344
How is fog in the temperate rainforest?
frequent
345
How tall are trees in the temperate rainforest?
60-70 meters high
346
How does productivity in temperate rainforests compare with tropical rainforests? (percent or fraction)
productivity is half
347
What are the soils of the temperate rainforest rich in?
organic matter
348
What biome is found in the eastern US, southern Canada, Europe, and eastern Asia?
temperate broadleaf forest
349
Temperate broadleaf forests occur in regions with what conditions?
moderate rainfall and high seasonal temperature variation
350
What is the dominant tree type of the temperate broadleaf forest?
deciduous trees
351
How does the productivity of temperate broadleaf forests compare with temperate rainforests?
they are similar
352
What causes the rich soil in the temperate broadleaf forest?
thick leaf litter due to plants shedding their leaves
353
What is the result of plants shedding their leaves in the temperate broadleaf forest?
a thick leaf litter forms, which decomposes into a rich soil
354
How do animal and plant diversity of temperate broadleaf forests compare to the tropics? (tropical rainforests)
both are much lower
355
As temperature decreases, the dominant deciduous vegetation in areas of moderate to high rainfall is almost exclusively ___________.
conifers
356
What tree type is common in the boreal coniferous forest?
conifers
357
How tall are the trees in the boreal coniferous forest?
10-20 meters
358
What are the main types of conifers found in the boreal coniferous forest?
spruces and firs
359
What species of animal is particularly common in the boreal coniferous forest?
large mammal species, such as moose, bear, wolf, and Siberian tiger
360
Productivity in boreal coniferous forests is roughly ___ of tropical rainforests.
36894
361
How is plant species diversity in the boreal coniferous forest?
low
362
What causes the dramatic fluctuations in bird and animal populations in the boreal coniferous forest?
variation in seed production due to yearly weather variation
363
What causes the dramatic variation of seed production in the boreal coniferous forest?
yearly weather variation
364
What do low temperatures and chemicals in the foliage of the boreal coniferous forest result in?
low leaf litter decomposition and poor soils
365
What causes the low leaf litter decomposition and poor soils in the boreal coniferous forest?
low temperatures and chemicals in the foliage
366
What happens when precipitation decreases to the point that there is not enough water to support dense forests?
vegetation shifts to grasslands
367
What are grasslands called in the US?
prairies
368
What are grasslands called in Asia?
steppes
369
Productivity of temperate grasslands is about ____ of tropical rainforests.
36894
370
What causes dead matter to accumulate in temperate grasslands?
decomposition is limited by low precipitation
371
What causes decomposition in temperate grasslands to be limited?
lack of precipitation
372
What creates the rich agricultural land in temperate grasslands?
organic matter accumulating due to a lack of decomposition
373
What is another name for the Tropical Scrub Forest?
the Savanna
374
Where is the Savanna most commonly found?
dry, tropical regions of Africa
375
What is the rainfall range for the Tropical Scrub Forest and Savanna?
10-150 cm/year
376
How much rainfall per month may there be on the driest 4 months of the Tropical Scrub Forest and Savanna?
less than 5 cm/month
377
What is scrub vegetation so small and stunted?
due to limited nutrients and a short growing season
378
In the Tropical Scrub Forest and Savanna, what vegetation is commonly found?
scrub vegetation
379
What type of consumer is a wildebeest?
a herbivore
380
What is respobsible for generating and maintaining the Tropical Scrub Forest and Savanna?
fires and grazing
381
How do productivity and species diversity of the Tropical Scrub Forest and Savanna compare with tropical rainforests?
they are significantly less
382
Where is the Mediterranean biome found?
in countries bordering the Mediterranean Sea, and California
383
What is the Mediterranean biome known as in California?
Chaparral
384
When does the Mediterranean biome receive most of its rainfall?
in the winter
385
What is vegetation in the Mediterranean biome made up of?
dense, woody shrubs and small trees
386
How are the leaves of vegetation in the Mediterranean biome?
small, leathery, and waxy to help retain water
387
What do the small, leathery, and waxy leaves found in vegetation in the Mediterranean biome help them do?
retain waster
388
How often do fires occur in the Mediterranean biome?
frequently
389
What adaptations have trees and shrubs in the Mediterranean biome evolved to protect them against the frequent fires?
fire-resistant bark
390
What are animals that are commonly found in the Mediterranean biome?
birds and small mammals, such as jackrabbits, kangaroo rats, chipmunks, mule deer, and lizards
391
What are areas receiving less than 25 cm/year of precipitation?
deserts
392
What is a desert biome?
an area that receives less than 25 cm per year of precipitation
393
Do deserts have to be hot?
No, they can cover a wide range of temperatures
394
How is the soil of the desert biome?
rocky or sandy
395
What vegetation is common in the desert biome?
sparsely spaced shrubs and grasses
396
Desert productivity ranges from _ to _ percent of that found in tropical rainforests.
0% to 5%
397
Desert species evolve adaptations to combat what?
the lack of water
398
Where does the tundra biome occur?
in the arctic region beyond the tree line
399
What is the tree line?
the upper limit of tree groth at high latitude or elevation
400
What does vegetation in the tundra biome consist of?
grasses, grass-like sedges, lichens, and dwarf trees
401
How is the soil in the tundra biome?
it is frozen year-round
402
What is the soil in the tundra biome known as?
permafrost
403
How much does the soil/permafrost in the tundra biome thaw during the summer?
.5 to 1 meters
404
What animal species is commonly found in the tundra biome?
rodent species, like lemmings, and sometimes birds
405
What causes the population of rodent species in the tundra biome to fluctuate?
dramatic variations in resources
406
What do most bird populations do during the winter time in the tundra biome?
they typically migrate south
407
Why are aquatic regions not divided into biomes?
because they lack the variety of plants and animals
408
What are the 2 major types of aquatic systems?
freshwater and marine
409
What can freshwater systems be divided into?
flowing rivers and standing waters
410
What type of freshwater system are rivers and streams?
flowing rivers
411
What type of freshwater system are ponds and lakes
standing waters
412
What are plants and animals that live on or near the bottoms of aquatic regions known as?
the benthic community
413
What is the dominant energy producer in most aquatic systems?
phytoplankton
414
How is the light in the open-water community?
sufficient for photosynthesis
415
What are lake and pond ecosystems influenced by?
thermoclines
416
What are thermoclines?
abrupt changes in the temperature of water, helps prevent the mixing of layers of the water
417
What do thermoclines help prevent?
the mixing of the different layers of water
418
What percent of Earth's surface is covered by ocean?
0.71
419
How does the ocean compare with the terrestrial biomes in terms of size?
it is larger than all the terrestrial biomes combined
420
Where in ocean ecosystems is there not enough light for photosynthesis?
100-200 meters down
421
How do most deep-water organisms get their food?
by migrating toward the surface or waiting for food to descend down
422
What is an exception to deep-water organsims having to wait for food to descend for migrate toward the surface?
volcanic vent communities
423
Where are volcanic vent communities found?
on the ocean bottom
424
What is a major limiting factor of marine ecosystems?
the low nutrient content of the water
425
What happens as a reslt of the low nutrient content of the waters in marine ecosystems?
species abundance and diversity near the surface is low
426
Where does peak species diversity in oceans occur?
2,000-3,000 meters
427
What are wetlands?
transititional areas between terrestrial and aquatic
428
Salt marshes, bogs, swamps, and intertidal areas are examples of ___________.
wetlands
429
What are the 3 types of wetlands?
marine, estuarine, and freshwater
430
What are marine wetlands known as?
the intertidal region
431
What is an estuarine wetland?
where salt and fresh water mix at the mouths of rivers
432
What type of wetland makes up 91% of all wetlands in the US?
freshwater wetlands
433
What type of wetland includes bogs, marshes, swamps, and peatlands?
freshwater wetlands
434
Freshwater wetlands makes up ___% of all wetlands in the US.
0.91
435
How are wetlands different from open waters?
they have soil at or near the surface for most of the year
436
The soil surface of wetlands never gets how deep?
more than 2 meters deep
437
What are biogeochemical cycles?
the cycling of elements between the biosphere, soils, and water
438
What is one of the main agents responsible for transporting chemical elements necessary for organisms?
water
439
What is the water cycle?
the movement of water through the atmosphere and over Earth's surface
440
What is the main driver of biogeochemical cycling on Earth?
the water cycle
441
What 3 things can happen when water comes in contact with vegetation?
it can return to the atmosphere, enter the ground, or move across land surface
442
What is transpiration?
the loss of water through the stomates, openings, in the leaves during photosynthesis
443
What is the combination of evaporation and transpiration called?
evapotranspiration
444
What happens when water goes into the soil?
it enters the groundwater system
445
What is the groundwater system?
the water that fills the spaces in rocks and sediments in the soil
446
What is rainfall draining from the land into waterbodies or sinking into the soil?
runoff
447
Eventually, where do streams and groundwater reach?
the ocean
448
What is the ultimate reservoir of water on Earth?
the ocean
449
What drives evaporation?
energy from the Sun
450
What is the main source of energy for the water cycle?
solar energy
451
How many processes run the carbon cycle?
4
452
What are the 4 processes that run the carbon cycle?
photosynthesis, respiration, decomposition, and combustion
453
What is taing carbon dioxide and incorporating it into plant material known as?
carbon fixation
454
What is carbon fixation?
when plants take CO2 from the atmosphere and incorporate it into plant material
455
When do plants respire?
at night
456
What happens when plants respire?
their carbon is returned to the atmosphere
457
What does combustion do with carbon?
it releases it back into the environment
458
What is the greatest amount of carbon tied up in?
carbonate rock
459
What usually happens when organisms die?
they decompose, returning their carbon back into the soil
460
What type of rock is organic matter, sedimentary rocks, shale, and limestone?
carbonate rock
461
Does the carbonate rock abiotic pool of carbon cycle quickly?
No
462
There is also a very large pool of _________ in the oceans, but it shows only a very small annual net gain.
carbon
463
Does the carbon in the oceans increase by a lot each year?
No
464
How is the chemistry of the oceans changing?
they are becoming more acidic due to more CO2 in the atmsophere
465
What is the most important path in the carbon cycle?
the movement between the atmospheric and biospheric pools
466
Without humans, is the carbon exchange between the biosphere and atmosphere at equilibrium?
Yes, it would be at steady state
467
What is the best known and most significant human alteration of the carbon cycle?
the burning of fossil fuels
468
What occurs when forests are burned to create pastures, grassland, and crop lands?
slash-and-burn agriculture
469
What is slash-and-burn agriculture?
when forests are destroyed to make room for agriculture
470
How is slash-and-burn agriculture bad?
it destroys biodiversity and adds large amounts of carbon to the atmosphere
471
Why is nitrogen critical for life?
because it is one of the elements in amino acids
472
What are amino acids?
the basic components of all organisms, contain nitrogen
473
In what organisms does nitrogen occur the highest concentration in?
plants
474
What percent of our atmosphere is nitrogen?
0.78
475
What do organisms need to be able to do in order to make direct use of atmospheric nitrogen?
they must be capable of nitrogen fixation
476
What is nitrogen fixation?
the conversion of nitrogen gas to a plant-available form, ammonium
477
What organisms are capable of nitrogen fixation?
cyanobacteria, bacteria and fungi associated with certain legumes like peas, and certain trees, like alders
478
What is atmospheric nitrogen also fixed by? (other than organisms)
lightning and combustion processes
479
When atmospheric nitrogen is fixed by lightning and/or combustion, what is produced?
nitrate anion
480
Nitrogen that has been fixed by plants is contained where in the plant?
the organic matter of the plant
481
What happens to the nitrogen in a plant when it dies and decomposes?
it gets released and becomes available for use
482
What is ammonification?
the conversion of organic matter to ammonium
483
What is the conversion of organic matter to ammonium?
ammonification
484
What organisms drive ammonification?
microorganisms
485
What is given off when microorganisms do ammonification?
ammonium cations
486
What typically occurs after ammonification to convert it to nitrate?
nitrification
487
What is the process in which ammonium is converted to nitrite and then to nitrate in a 2-step process?
nitrification
488
How many steps are in nitrification?
2
489
How important is nitrite?
it is of minor importance
490
What is a negative of nitrite?
it can be toxic to human infants
491
Nitrate is susceptible to _______________.
leaching
492
What is leaching?
where an element or molecule is washed out of the soil by moving water
493
A high accumulation of nitrate in wet soils can lead to what?
denitrification
494
What is denitrification?
the conversion of nitrate into nitrous oxide
495
What is often the limiting element in terrestrial systems?
nitrogen cycle
496
What is the nitrogen cycle important in?
the regulation of productivity and plant growth in ecosystems
