Exam Two: Learning Objectives Flashcards
(244 cards)
1
Q
Water is a __ solvent
A
universal
2
Q
Water content of organisms must stay between __ and __ of body mass
A
60, 90
3
Q
What is the medium in which all biochemical reactions necessary for life occur?
A
water
4
Q
Water moves __ concentration gradients from __ to __ water pressure
A
DOWN
higher; lower
5
Q
Water moves down a concentration gradient between terrestrial organisms and air via __ __ __
A
vapor pressure deficit
6
Q
Water moves down a concentration gradient between aquatic organisms and the water they are in via __ __ __
A
osmotic pressure gradients
7
Q
Water moves down a concentration gradient along the soil-plant-atmosphere continuum via __ __
A
water potential
8
Q
Water will flow from an __ to __ via evaporative water loss
A
organism; air
9
Q
Define vapor pressure deficit?
A
difference in the amount of water vapor air could hold (given its temperature) and the amount it is actually holding
10
Q
Evaporative water loss is determine in party by an organism’s __ __ adaptations
A
water-retaining
11
Q
Air is always __ than the inside of an organism, and water always flows __ a concentration gradient, so water will flow from an __ to the __ via __ __ __
A
drier; down
organism; air
evaporative water loss
12
Q
Describe the VPD in warm and cold air
A
warm air can potentially hold lots of water as vapor,
cold air cannot hold a lot of water
13
Q
VPD will be high if the air is _ and __ but low if air is __ or humidity is __
A
warm; dyr
cool, high
14
Q
Why is the VPD low if humidity is high?
A
humid air already has lots of moisture and cannot hold much more
15
Q
Evaporative water loss is influenced by _ __ __
A
vapor pressure deficit
16
Q
Discuss the consequences of vapor pressure deficit if VPD is high (warm, dry air)
A
water will evaporate from terrestrial organisms
water loss (bad)
evaporative cooling (good)
17
Q
Discuss the consequences if VPD is low (cool, humid air)
A
less water will evaporate from terrestrial organisms
minimal water loss (good)
little possibility for evaporative cooling (bad)
18
Q
Water moves between aquatic organisms and the water they are in via __ __ __
A
osmotic pressure gradients
19
Q
Water and solutes move __ concentration gradients
A
down
20
Q
How does water transport from the soil through the plant to the atmosphere takes place in?
A
the soil-plant-atmosphere continuum
21
Q
Soil, plant, and atmosphere are interconnected by?
A
a continuous film of liquid water
22
Q
Water flows to a more __ water potential
A
negative
23
Q
Define water potential
A
the gradient from which water moves from the soil through the plant to the atmosphere
24
Q
What factors determine water potential in a plant?
A
solutes, matric, and pressure
25
What factors determine water potential in a soil?
matric
26
A free standing body of pure water has a water potential of _, while in nature, water potentials have a __ (__) value
zero
lower; negative
27
What are three factors that reduce water potential in soil-plant systems (make water potential more negative)
solutes
matric forces
negative pressure
28
Discuss the water potential in solutes
water is drawn toward areas with a lot of solutes
29
Discuss the water potential in matric forces
thin films of water are attracted to (hard to pull off of) the surface of soil particles, cells, or walls of narrow vessels in plants
30
__ films are held more tightly, and __ soil particles provide more surfaces for water films to adhere to
thinner; finer
31
Discuss the water potential of negative pressure
water is drawn ttowards areas of low pressure (water evaportation into dry air imposes a 'sucking' action on wetter plant tissues)
32
How do plants get water through roots from soil?
water potential of roots is lower (more negative) than water potential of soil
33
Terrestrial animals gain water through __ and __
absorption; consumption(eating and drinking)
34
What are the two forms of food water?
moisture content of food and metabolic water
35
metabolic water generated during __ __ - water is produced by the __ as it breaks down __ __
cellular respiration
consumer
organic matter
36
Individuals who originated from the __ location showed the lowest evaporative water loss
dry
37
Discuss evaporative water loss and the trade off of skin adaptations
skin thickness and composition can be adaptations to regulate evaporative water loss and thus water balance
there's a tradeoff with ability to evaporatively cool and exchange gases
38
How do desert scorpions manage heat and water budgets?
burrowing during the day reduces heat gain and reduces evaporative water loss
low metabolism and cuticle covering
39
How do desert cicadas regulate heat and water budgets?
dump lots of body heat through evaporation
adaptation for high water gain through drinking, pierce mesquite trees and drink plant fluids
40
What are two ways plants compensate for variation in water availability?
drop leaves and increase gain with deeper roots
41
Dropping leaves in response to water stress can be an __ way to lose water. Instead they shut off __
expensive; stomate
42
In response to soil drying, some plants send a hormonal __ to the guard cells that closes the __ to prevent __ loss
signal
stomata
water
43
Define stomata
gas-exchange pores on the underside of leaves
44
Adaptations revealed in __ __ responses to environmental change
short-term
45
The ability to acclimatize is an _
adaptation
46
In marine environments, water tends to diffuse __ of organisms, via __ and __
out
concentrated urine
drinking water
47
In freshwater environments, water tends to move __ to the organisms via methods of?
into
large volumes of dilute water
48
What are two adaptations to maintain osmotic balance in water that is saltier than inside the organism ?
drink water and dump solutes
49
Isosmotic organisms have internal __ and __ concentrations that match those of their environment, but must selectively control __ of specific solutes
water; salt
exchhange
50
Define trophic
feeding and nutrition
51
What is the purpose of feeding?
to grow, heal, move, reproduce, achieve homeostasis, and maintain cellular order
52
What are the three trophic categories
photosynthetic autotrophs
chemosynthetic autotrophs
hetertrophs
53
Discuss the carbon and energy source of photosynthetic autotrophs
CO2
sunlight
54
What organisms are photoautotrophs ?
organisms with light-harvesting pigments (usually chlorphyll)
vascular plants
microalgae
phytoplankton
bacteria
eukaryotic algae
55
Where does photosynthesis occur?
chloroplasts
56
Define chloroplasts
organelles in plant cells that have sunlight-capturing pigments (chlorophyll a)
57
Cyanobacteria are photosynthetic __, the cell is essentially a __
prokaryotes; chloroplast
58
What are the three components of photosynthesis?
light reactions, carbon fixation, and biosynthesis
59
Discuss the light reaction component of photosynthesis
absorb light; transfer energy to ATP and electrongs
60
Discuss the carbon fixation component of photosynthesis
C from CO2 is captured
61
Discuss the biosynthesis component of photosynthesis
organic biomolecules are synthesized
62
What is C3 photosynthesis?
found in most plants and algae
63
Discuss the synthesis of C3 photosynthesis
C from CO2 combines with a 5-carbon compound called ribulose bisphosphate (RuBP)
Rubisco catalyzes the combination of RuBP and C
creating two, three carbon molecules which are then used to make glucose
64
Water loss is a __ on C3 photosynthesis
limitation
65
Water loss = closing of __, plant can't take in __, with stomata closed, __ combines with O2 in __ instead of with __. Reduces the __ capture and thus reduces the __ of organic C
stomata
CO2
RuBP
photorespiration
CO2
synthesis
66
What are the three photosynthetic pathways?
C3, C4, and CAM
67
What is the purpose of C4 and CAM pathways?
perform carbon fixation at a different time or location when and where light reactions and biosynthesis can occur
68
CAM and C4 are __ of C3
elaborations
69
CAM and C4 pathways initially fix C with __ instead of Rubisco, because it is better at catching __
PEP C
CO2
70
How do CAM and C4 pathways enable photosynthesis without light?
C fixation requires open stomata, but light reactions and biosynthesis do not
71
CAM: PEPC catches __ during the night, then delivers it to __ during the day, at which point the normal __ pathways occurs
CO2
Rubisco
C3
72
C4: PEPC catches __ in the __ cells, then delivers it to __ in the bundle sheath cells, which reside __ in the leaf tissue and then the normal __ pathway occurs
CO2
mesophyll
deeper
C3
73
What is the advantage of C4 and CAM pathways?
Plants can open stomata less and still get needed CO2, resulting in less photorespiration and less water loss
74
PEP C just __ the CO2-derived C __
holds; temporarily
75
CAM performs C fixation at a different __ and C4 performs C fixation at a different __
time
location
76
CAM; C fixation at night when __ can safely open with low __ loss
stomata
H2O
77
C4 plants perform better in high __ and __, and low __ availability
light; temperature
water
78
C4 plants includes half the __ and found prominently in __ and __ grasses, contributes to 20% of __ __ __ and includes many species of commercial importance (corn)
grasses
tropical; subtropical
terrestrial plant production
79
Temperature predicts balance of __ and __ plants
C4, C3
80
In locations that are warmer, a __ percentage of grass and shrub species are __
higher; C4
81
__ species dominate in grasslands and shrublands of __ regions
C3
cooler
82
CAM plants have the best __ __ _
water use efficency
83
CAM plants are found in __ and __-__ environments, including many families including __, __, __, and __
arid; semi-arid
succulents, cactuses, bromeliads, orchids
84
CAM plants have slower __ but great __-__ __
photosynthesis; water-use efficency
85
Describe water use efficency
use (and loss) very little water per gram of biomass added; even better than C4
86
What is the carbon and energy source of chemosynthetic autotrophs
CO2
reduced inorganic compounds
87
Chemosynthetic autotrophy: reduced __ provide _ for eTC, sets up __ __, which leads to __ and __ of organic carbon, needs a terminal electron __ (can be _)
molecules, e-
proton gradient
ATP synthesis, biosynthesis
acceptor, O2
88
Compare and contrast chemo and photo autotrophs?
both synthesize ATP and fix C, but get e from reduced inorganic molecule rather than sunlight splitting water
89
What are two examples of reduced molecules in chemosynthetic autotrophy?
H2S and NH4+
90
What is an important example of chemosynthetic autotrophy
nitrifying bacteria play a very important role in the nitrogen cycle
91
What is the carbon and energy source for heterotrophs?
organic C and organic C
92
What are the three major categories of heterotrophs?
herbivores, carnivores, and detritivores
93
What are three challenges of herbivores (heterotrophs)?
chemical defenses, stoichiometric constraints, and physical defenses
94
Define a nutrient
chemical element required for the development, maintenance, and reproduction of an organism
95
What is an example of a nutrient?
Nitrogen
96
What are the five primary nutrient requirements?
C, O, H, N, and P
97
Why are nutrients important?
to maintain chemical composition, i.e. obtain nutrients in the proper ratios
98
What is a stoichiometric constraint?
difficulty getting food with proper nutrient ratios
99
What is a challenge detritivores face?
stoichiometric constraints
100
What is the diet of detritivores?
dead organic material (detritus)
101
Detritivores: __ and __ do most decomposition, also includes lots of __ __ and __ of many sizes, known as the __
fungi, bacteria
eukaryotic protozoans, animals
recycles
102
Carnivores have a good __ match
stoichiometric
103
high food __ is balanced by low __ availability
quality; prey
104
Why is most prey unfavorable to consume?
hard to find, well defended
105
Energy to catch prey might be _ than the energy value of the prey
greater
106
There is energy __ up trophic levels
loss
107
A carnivores potential diet items are __ similar, which permits diet __ and __
nutritionally
flexibility; variability
108
What is the equation of profitability?
value of food item/ energy and time cost of finding, catching, subduing, eating, and digesting food item
109
Optimal foraging: the most common food option is not always the most __ favorable
energetically
110
Net energy gain by bluegill sunfish is maximized by?
selecting larger prey items, even though they are rare and require more energy to hunt
111
Carnivores are often _--__ predators, hence __ animals feed on __ prey and smaller animals feed on __ prey
size-selective
larger; larger
smaller
112
While animals may chose prey of a certain size, or with the greatest net energetic return, plants will invest in either __ or __ depending on which resource is most __
roots (below ground)
shoots (above ground)
limiting
113
More investment of roots when below ground (soil) resources are __, i.e. __ root growth with __ supplies of soil nitrogen or soil water
limiting
more
lower
114
The rate at which organism take in energy is limited either by _- or __
the environment, internal constraints
115
Why does the environment limit energy?
environment does not provide sufficient energy
116
How do internal constraints limit energy?
lots of energy is available, but organism is incapable of taking it all in
117
When resources are __, the rate of resource use by organisms is limited by how __ they can eat or absorb the resource
abundant, quickly
118
When resources are __, the rate of acquisition by organisms is limited by __ __
scarce
resource supply
119
What are two examples of internal constraints ?
photosynthetic rate and photon flux density
feeding rate and food availability
120
What do photosynthetic response curves show?
How the rate at which a plant takes in energy (photosynthetic rate) responds to an increase in the rate at which energy is supplied
121
photon flux density is equal to?
rate at which light particles hit the plant
122
Where are external constrains on energy intake shown?
over the rising part of the curve at low levels of light
123
What does the curve on a photosynthetic rate show?
the rate at which a plant acquires energy (Y axis) is constrained by the rate at which the environment supplies energy to the organisms (x axis)
external constraints on energy intake
124
Where are internal constraints represented on an energy intake curve?
over the flat part of the curve at high levels of light supply
125
What does the internal constraints curve represent on energy intake?
the rate at which a plant acquires energy (y axis) via photosynthesis is constrained by its own availability to use the plentiful supply of light
126
T/F: Plant species show different photosynthetic response curves
true
127
What do the differences in photosynthetic response curves represent?
how adaptation to one set of conditions has costs in other conditions
128
shade species that can photosynthesize well in __ light cannot respond to __ light
low; abundant
129
Sun species that can take advantage of __ light levels, don't do well in the __
high; shade
130
Sun species that synthesize lots of __ to harvest abundant light, but protein synthesis requires a lot of __; costly if incoming light is __
protein
energy
insufficient
131
Energy intake by animals also shows __ and __ constraints, via __ __ curves
external, internal
functional response
132
Heterotrophs: different -vores use different, __ __, each with some __(stoichiometric mismatches, well-defended prey)
food types
constraint
133
Sexual reproduction involves the ?
input of genetic material from two individuals
134
Why are social relations important?
they directly influence an organisms reproductive success - its fitness, or contribution of genetic material to future generations
135
Define sexual selection
selection for traits that improve mating success and thus reproduction rate
136
Distinguish the difference between inter and intra selection
inter - competition among mates, through fighting
intra - selection by females, peacock feathers
137
Why do antlers develop due to intersexual selection?
males have to fight to mate, bigger antlers equals more mating
138
male guppy coloration shows an example of selection for a trait through __ __ (__) and against that same trait through predation
mate choice; interselection
139
Where will you find mostly dull-colored guppies?
areas of high predation
140
Discuss the counteracting forms of selection between male choice and predation in crickets
interselection
females of parasitoid fly find male crickets by listening for chirping, females select males by their chirps
141
Mate choice by females may be based on male ability to provide __
resources
142
Do large or small male scorpion flies have a higher mating success?
large
143
Male scorpionflies provide a resource, and therefore have a high __ success, but this requires a lot of __
mating
energy
144
Mating in plants is ?
nonrandom
145
What evidence is there that plants mate non-randomly?
multiple pollen donors provides mating options for maternal plant
146
Discuss the good genes hypothesis
ornamental traits may signal that a male is good at obtaining resources
ornamental traits may signify that a male has other more functionally 'useful' traits
mating with an ornamental male increases chances that sons and daughters will have those useful traits
147
Discuss the sexy sons hypothesis
ornamental traits are nothing more than ornamental; they do not signal that a male has other useful traits
but females are attracted to these ornamental traits
mating with an ornamental male increases the chances that sons will be ornamented and thus attract mates of their own
148
Define fitness
genetic contribution to future generations
149
Kin selection will favor __, which can increase one's __ __ (all offspring with whom one shares genes)
altruism, inclusive fitness
150
Altruism is associated with __
sociality, aka group living
151
Sociality is often characterized by individuals that don't __
reproduce
152
In some species, individuals live in __ groups, referred to as __
cooperative; sociality
153
If an animal has __ alleles, its likely its nieces do to, helping raise its nieces advances its __ alleles on to __ generations (__)
helper; helper
future
altruism
154
What are two benefits to helpers in cooperative breeding arrangements?
inclusive fitness
improve own chance of breeding (gain experience, delay reproduction)
155
What is an example of social organisms?
Bees, woodhoopoes, and monkeys
156
Define philopatric
stay near home
157
How are woodhoopoes an example of sociality?
philopatric, helping behavior by siblings and half-siblings, inheritance of quality habitat, delayed reproduction (females), higher fitness
158
__ quality territory: lots of sturdy __ __ in trees, favorable years = years when the dry season is actually __, __ of food
high; roosting cavities
dry; lots
159
Eusociality is a highly __ form of sociality with __ living groups, __ care for young, and very high __ among individuals. There is a division of individuals in __
specialized
multigeneration
cooperative
relatedness
castes
160
Discuss the castes in eusocialized groups
groups of physically distinctive individuals that performs specialized tasks, often related to body size
sterile, non-reproductive, and reproductive groups
161
Adaptations that affect the fitness of individuals will influence __ and __
range, dynamics
162
A species cannot survive in locations where the value of an __ variable falls outside its __ range of __
environmental, physiological, tolerance
163
Define the principle of allocation
each individual organism has a finite (limited) quantity of resources that it can use for all necessary life processes,
164
Individual organisms cannot __ and __ under environmental conditions where the cots of basic maintenance are too __ or conditions are __
grow; reproduce
high; lethal
165
A populations geographical distribution (__) will be limited to areas where sufficient __ can be __ to __ and __
range
energy
allocated
growth; reproduction
166
What are three examples of environment limiting range?
coastal ghost forests, american alligator, and eastern phoebe
167
What is a fundamental niche?
acceptable suite of physical conditions, in the absence of interactions with other species
168
What is a realized niche?
suite of environmental conditions, including physical conditions and biotic interactions, in which a species can survive, grow, and reproduce
169
Chthamalus adults do not persist in mid-intertidal zones because?
they can't compete with Balanus
170
Biotic and abiotic factors combine to shape __ __ and fine-scale __
realized niche; distribution
171
What impacted bettong range collapse?
biotic interactions - predation and competition for resources
172
Hawaii akepa bird is limited to the tops of mountains by __, which is limited by __
malaria
temperature
173
Discuss the impact of climate change on Hawaii akepa birds
With temperatures rising, birds may be confined to a higher elevation because malaria can now travel further up the mountain
174
Most individuals in a population are found in just a __ spots, cluster in areas where environment meets __ __ which describes _- __
few
niche requirements
patchy distribution
175
What are two examples of patchy distribution?
trees and red-eyed vireos
176
Why might young plants have a clumped distribution?
there are a limited number of safe locations, seeds don't disperse far, and asexual reproduction
177
Regular distributions tend to result from __ and __, where organisms or colonies are...
aggression; competition
as far away from one another as possible
178
The environment limits __
distribution
179
Populations distribution is limited to __ __ where environment matches __
geographic locations
niche
180
Population range and patchy distributions respond to __ and __
environment
patchy distribution
181
Define dispersal
the movement of individuals and propagules
182
Dispersal can __ the size of a populations range when individuals move into __ areas not currently occupied by the __
increase; new; occupied
183
Dispersal can __ the size of a populations range when individuals move __ of a portion of the existing range
decrease; out
184
Dispersal can shift the location of a range when
a population shifts its spatial distribution
185
Discuss the dispersion of a collared dove
started in Turkey and spread to all of Europe in 90 years due to dispersal of young birds (adults are sedentary)
186
Discuss the dispersal of maple trees
range expanded as climate changed and areas become more suitable to maple, climate changed to match the maple's niche
187
Describe the dispersal of the honeybee
range expansion occurred rapidly after a dispersal barrier (Atlantic ocean) was overcome, Americas' environment was already suitable, matched the bee's niche
188
What is the primary difference in dispersal patterns between bees and maple trees and doves?
bees - dispersal barrier
doves and maple trees - environmental limitation
189
Climate change is shifting ranges approx _ m __ a decade
6; upward
190
Define numerical response
change in consumer density in response to change in resource supply
191
What are the two mechanisms of numerical responses?
1 consumers are attracted to food, e.g. predators disperse to areas of abundant prey (instantaneous)
2 consumers produce more offspring. More food = more reproduction and offspring survival (lagged response, e.g. more food this year = more babies next year)
192
Density of predatory birds rise and falls in nearly perfect with with abundance of __ (_-), suggesting more voles = more __, representing a mechanism of __ __, voles follow __, (_) and birds produce more __(_)
prey; voles
reproduction
numerical response
food (#1)
offspring (#2)
193
At a given location, bear and seagull densities __ as these predators come and go
fluctuate
194
Gulls and bears disperse from stream to stream, showing up at each stream when __ arrives and leaving when __ are depleted
food (salmon)
salmon
195
The movement of __ is perhaps the most distinctive feature of streams
distinctive
196
Downstream flow has a strong __ on dispersal of stream __
influence; organisms
197
Define drift
downstream dispersal which can be active or passive
198
Define colonization cycle
upstream dispersal that balances drift
199
Discuss the lifecycle of mayflies
live in water for up to a year as juveniles, emerge as an adult (aerial) fly upstream, disperse through flight to reproduce and lay eggs in water
200
Population distributions are _- or __ and __ is important for population dynamics
patchy, discontinuous
dispersal
201
Define a metapopulation
network of semi-isolated local populations that are linked by periodic exchange of individuals
202
Butterflies were likely to leave small local populations (__ __) for large ones (__ __)
source populations
sink populations
203
Background matrix of metapopulations affects __ of dispersal routes between patches
viability
204
Define population dynamics
refers to changes in the distribution and density of a population
205
What happens if metapopulation connections are severed?
loss of source-sink dynamics, depleted patches cannot get replacement individuals
206
Smaller populations have __ genetic diversity
less
207
Which two aspects of population density add individuals?
birth and immigration
208
Which two aspects of population density remove individuals?
death and emigration
209
What does a survivorship curve represent?
a schedule of mortality and survivorship, i.e. when, or at what ages, organisms die
210
In a population age distribution graph __ is on the y axis and __ is on the x axis
number of survivors, age
211
A life table is a tabular version of a __ __
survivorship curve
212
What's the difference between a static and cohort life table?
static - age dist. at a point in time
cohort - tracks a single cohort as it ages
213
What do age distributions show?
abundance of each age class in a population
214
Define recruitment
adding new members to the population through birth and survival of young
215
How can recruitment be shown on age distributions?
shown one year AFTER event
216
What is a type one survivorship curve?
low infant and juvenile mortality rate, most die elderly (humans and dall sheep)
graph is upside down exponential
217
What is a type II suviorship curve?
graph is linear
all ages have same mortality rates (birds and mud turtle)
218
What is a type III survivorship curve?
juvenile mortality rate is the highest, and lowest is adult (plants)
curve is exponential
219
What does Ro stand for?
net reproductive rate
average number of lifetime offspring per individual
220
What does T stand for?
generation time,
average age of reproduction
221
What does r stand for?
per capita rate of increase
interpreted as birthrate minus death rate
222
What does a positive r value mean? negative?
positive means population is growing
negative means population is declining
223
What does rmax represent?
intrinsic rate of increase
r when conditions are ideal
224
Populations are limited by __ __ and __ __
physical environment
biotic interactions
225
Population densities change via __, __, __
dispersal, birth and death
226
What are the five limited conditions populations can grow exponentially for a limited time under certain conditions?
favorable environments, low population densities, abudnant resources, and few natural enemies
conditions are most likely with invading and recovering populations
227
What are two examples of exponential growth?
scots pine after post-glacial colonization
whooping crane after protection
228
Populations cannot continue to grow exponentially because?
eventually some factor limits growth,
the environment (biotic and abiotic) limits population growth by changing birth and death rates
229
What are the general shape of population growth curves?
geometric, exponential
s-shaped, logistic
230
What is the relation of N, t, and r in an exponentially growing population?
dN/dt = rN
dN/dt = change in population density over time
r = per capita rate of increase
N = population density
231
What are three examples of logistic growth?
food becomes limited and environment grows toxic,
breeding space becomes limited
attachment space becomes limited
232
Define carrying capacity
the population density at which births = deaths, and there is no net growth
233
Discuss a logistic population growth (graph)
early exponential growth when small population hasn't depleted resources
population gets large enough that some factor beings to limit it; growth curve starts to bend back down
population density is so high that resources are only sufficent to support enough births to replace deaths (no net population growth)
234
In a logistic curve, __ goes to zero as population density approaches __ __
dN/dt
carrying capacity (k)
235
What is the equation for logistic population growth?
dN/dt = rmax N (1-N/K)
236
Equation for logistic growth reveals __ in growth rate at __ population densities
slowdown
high
237
Recognize that the __ and __ environmental factors that influence population density are, themselves, also __ over time.
physical, biotic
changing
238
What does r max look like for exponential and logistic graphs?
expo - constant, straight line
linear decrease to 0 which is k
239
For a cactus finch, more __ means more __ and therefore more __
rainfall, food, offspring
240
Discuss the population dynamics of an excess rainfall population of prickly pears
massive cactus mortality from intense rainfall
exploitation of cactus by finch kept population low during drought years
241
The effect of density dependent factors on a population depend on the impacted __ __
population's density
242
If a population of plants is more sensitive to a disease when the population is large (high N) than when the population is small (low N), the disease has a __ __ influence on the population of plants
density dependent
243
If 50% of the plants in a plant population die when there is a frost, regardless of the plant population density, then frost has a __ __ influence on plant production
density independent
244
Influence of density independent factors ___ depend on the density of the population being affected
does not
