Units 1-4 Study Set Flashcards
(194 cards)
1
Q
Scientific method
A
- Make Observations
- Background research/Ask a question
- Form a hypothesis
- Design an Experiment
- Gather/Present Data
- Analyze Data/Draw Conclusions
2
Q
Independent variable
A
- A variable that stands alone and isn’t changed by the other variables you are trying to measure
- The cause of the experiment
- X-axis
3
Q
Dependent variable
A
- What you measure in the experiment and what is affected during the experiment
- The effect of the experiment
- Y-axis
4
Q
Energy
A
The ability to do work or transfer heat
5
Q
Joule
A
The amount of energy used when a 1-watt electrical device is turned on for 1 second
6
Q
Energy conversions
A
- energy = power × time
- power = energy ÷ time
7
Q
Electromagnetic radiation
A
A form of energy emitted by the Sun that includes, but is not limited to, visible light, ultraviolet light, and infrared energy
8
Q
Photon
A
A massless packet of energy that carries electromagnetic radiation at the speed of light
9
Q
Potential energy
A
Energy that is stored
10
Q
Chemical energy
A
Potential energy stored in chemical bonds
11
Q
Kinetic energy
A
Energy of motion
12
Q
Temperature
A
The measure of the average kinetic energy of a substance
13
Q
1st Law of Thermodynamics
A
Energy is neither created nor destroyed, but may be converted from one form to another
14
Q
2nd Law of Thermodynamics
A
When energy is changed from one form to another, some useful energy is always degraded to lower quality energy
15
Q
Entropy
A
The amount of disorganization present in a system
16
Q
Open system
A
A system in which exchanges of matter or energy occur across system boundaries
17
Q
Closed system
A
A system in which matter and energy exchanges do not occur across boundaries
18
Q
Input
A
An addition to the system
19
Q
Output
A
A loss from the system
20
Q
Steady state
A
A state in which inputs equal outputs, so that the system is not changing over time
21
Q
Negative feedback loop
A
A system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring
- Helpful
22
Q
Positive feedback loop
A
Change in a system is amplified
- Undesirable
23
Q
Ecosystem
A
○ Some have well-defined boundaries, while others do not
* The biotic and abiotic components of
an ecosystem provide the boundaries
that distinguish one ecosystem from
another
* Some ecosystems are very small
* Each ecosystems interact with each
other through the exchange of
energy and matter
24
Q
Biosphere
A
The region on our planet where life resides
25
Predator
Eats other organisms
26
Prey
Organisms eaten by other organisms
27
Symbiosis
a close, long-term interaction between two species in an ecosystem
28
Mutualism
Both organisms benefit
29
Commensalism
One organism benefits, one organism neither benefits nor is harmed
30
Parasitism
One organism benefits and one is harmed
31
Competition
Organisms compete when they seek the same limited resource
32
Interspecific competition
Members of a different species compete for the same resource
33
Intaspecific competition
Members of the same species compete for resources
34
Producers/autotrophs
Organisms that use the Sun to produce usable energy
35
Photosynthesis
The use of solar energy to convert carbon dioxide and water into glucose and oxygen
36
Cellular respiration
A process by which cells unlock the energy of chemical compounds
37
Aerobic respiration
The opposite of photosynthesis, where oxygen and glucose are converted into energy, carbon dioxide, and water
38
Anaerobic respiration
- Cells convert glucose into energy in the absence of oxygen
- does not provide as much energy
39
Consumers/heterotrophs
Organisms incapable of photosynthesis who must obtain their energy by consuming other organisms
40
Herbivores/primary consumers
Consumers that eat producers
41
Carnivores
Consumers that eat other consumers
42
Secondary consumers
Carnivores that eat primary consumers
43
Tertiary consumers
Carnivores that eat secondary consumers
44
Trophic levels
The success of organisms consuming one another
45
Food chain
The sequence of consumption from producers through tertiary consumers
46
Food web
- A complex model of how energy and matter move through trophic levels
- All species in an ecosystem are connected to one another
47
Omnivores
Organisms that operate at several trophic levels
48
Scavengers
Organisms that consume dead animals
49
Detritivores
Organisms that break down dead tissues and waste products into smaller particles
50
Decomposers
The fungi and bacteria that complete the breakdown process by converting organic matter into small elements and molecules that can be recycled back into the ecosystem
51
Gross primary productivity (GPP)
- A measure of the total amount of solar energy that producers in an ecosystem capture via photosynthesis over a given amount of time
- Indicates the total amount of energy captured by producers
52
Net primary productivity (NPP)
- The energy captured minus the energy respired by producers
- The greater productivity of an ecosystem, the more primary consumers can be supported
53
Biomass
The total mass of all living matter in a specific area
54
Standing crop
- The amount of biomass present in an ecosystem at a particular time
- not the same as productivity
55
Ecological efficiency
- The proportion of consumed energy that can be passed from one trophic level to another
- 10% average across all ecosystems
56
10% rule
Only 10% of energy from one trophic level is able to move up to the next
57
Trophic pyramid
A method of representing the distribution of biomass among trophic levels
58
Biogeochemical cycles
The movements of matter within and between ecosystems
59
Hydrologic cycle
The movement of water through the biosphere
60
Evapotranspiration
- The combined process of evaporation from land surfaces and transpiration from plants
- An important component of the hydrologic cycle as it returns water vapor back into the atmosphere
61
Transpiration
The process by which plants release water vapor into the atmosphere through their leaves
62
Steps of the hydrologic cycle
1. Water evaporates from the Earth and into the atmosphere: Heat from the sun causes water to turn into water vapor and rise into the atmosphere, while plants can release water from their leaves.
2. Once the water has evaporated into the atmosphere, it comes back down to the Earth in the form of precipitation (rain, snow, hail/sleet, etc)
63
What happens to water when it returns to Earth?
1. Surface runoff
2. Percolation
3. Photosynthesis
64
Surface runoff
- Water that flows over the land surface rather than infiltrating into the ground
- Occurs when rainfall or snowmelt exceeds the soil's ability to absorb it or when the ground is already saturated
65
Percolation
- The process of water seeping through soil or rock layers and moving downward into the ground
- The water will be absorbed by the ground and will become part of the Earth’s groundwater stores
66
Human impacts on the hydrologic cycle
- Clear-cutting forests can lead to soil erosion and flooding
- Erosion and heat waves can become extreme and cause harm to humans and other ecosystems
- Pollution of water and climate change caused by human presence on Earth depletes and dirties water supply
67
Carbon cycle
The movement of carbon around the biosphere
68
Photosynthesis and the carbon cycle
- When photosynthesis occurs, CO2 from human activity and other natural processes is regulated and converted to oxygen, essential for the Earth's health and human survival
- Since CO2 is a greenhouse gas, preventing its overabundance is important so as to mitigate the effects of climate change
- The CO2 that plants retain is kept in their plant tissue, which eventually dies
- Decomposers will process that matter, leaving all carbon in the soil or nearby surroundings
69
Carbon sinks
Natural or artificial reservoirs that absorb and store carbon dioxide from the atmosphere, helping to mitigate climate change
70
Carbon exchange
The ocean absorbs some CO2 from the atmosphere, and it releases roughly the same amount of CO2 back into the atmosphere
71
Sedimentation
- The process by which particles settle out of a fluid (such as water) and accumulate at the bottom, forming layers of sediment over time
- The CO2 combines with calcium ions in the water to form calcium carbonate, which sinks to the bottom of the ocean and accumulates
- If left undisturbed, it can cause accumulation of carbon, but upon disturbance that carbon is reintroduced to the atmosphere and continues its journey through the carbon cycle
72
Fossil fuels
Natural resources formed from the remains of ancient plants and animals that have been buried and subjected to heat and pressure over millions of years
73
Macronutrients
One of six key elements that organisms need in relatively large amounts; nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur
74
Nitrogen cycle
The movement of nitrogen around the biosphere
75
Nitrogen fixation
Allows nitrogen gas to be converted into a form that can be used by plants and animals, such as ammonia (NH3) or nitrate (NO3)
76
Nitrification
The process by which ammonia (NH3) is converted into nitrite (NO2-) and then into nitrate (NO3-), primarily carried out by bacteria
77
Assimilation
- The process in which plants and animals take up nutrients from their environment and incorporate them into their own tissues for growth and development
- This nitrogen can be synthesized by consumers, or it can run into the ocean, providing aquatic ecosystems with enough nitrogen
- When these organisms die, decomposition occurs and organic nitrogen present in these organisms through the nitrogen cycle reverts back into ammonium
78
Mineralization
- The process by which organic matter, such as dead plants and animals, is broken down into inorganic substances like minerals
- This releases nutrients back into the soil or water for use by other organisms
- Last step before nitrification can begin again
79
Denitrification
The process by which nitrate is converted back into nitrogen gas
80
Ammonification
The conversion of organic nitrogen compounds into ammonia (NH3) by decomposer bacteria
81
Phosphorus cycle
The movement of phosphorus around the biosphere
82
Steps of the phosphorus cycle
1. When materials like rock are weathered, organic phosphorus is released into surrounding environments
2. It is then transported between land and water through aquatic functions like rain or excess runoff
3. After phosphorus has been transported between groundwater and soil, living organisms can absorb it and use it for production of DNA and other important biomolecules
4. These absorbers will eventually die, and their decomposition will release phosphorus back into the environment to restart the cycle
83
Eutrophication
Excessive richness of nutrients in a lake or other body of water, frequently due to runoff from the land, which causes a dense growth of plant life and death of animal life from lack of oxygen
84
Geologic uplift
The process by which Earth's crust is raised, resulting in the elevation of landforms such as mountains and plateaus
85
Terrestrial biomes
Geographical regions that each have a particular combination of average annual temperature and precipitation and contain distinctive plant growth forms that are adapted to that climate
86
Aquatic biomes
Biomes categorized by particular combinations of salinity, depth, and water flow
87
Habitat
An area where a particular species lives in nature
88
Oligotrophic
A lake with a low level of productivity
89
Mesotrophic
A lake with a moderate level of productivity
90
Eutrophic
A lake with a high level of productivity
91
Ecosystem services
The process by which life-supporting resources, such as clean water, timber, fisheries, and agricultural crops are produced
92
Environmental indicators
An indicator that describes the current state of an environmental system
93
Five global-scale environmental indicators
○ Biodiversity
○ Food production
○ Average global surface temperature and carbon dioxide concentration in the atmosphere
○ Human population
○ Resource depletion
94
Biodiversity
The diversity of life forms in an environment
95
3 scales of biodiversity
- Ecosystem
- Species
- Genetic
96
Genetic diversity
- A measure of the genetic variation among individuals in a population
○ Populations with a high genetic diversity are better suited to respond to environmental change
97
Species diversity
- The number of species in a region or in a particular ecosystem
○ Higher species diversity causes more resilience to environmental changes and are more productive
○ Critical environmental indicator
98
Speciation
The evolution of a new species
99
Background extinction rate
The average rate at which species become extinct over the long term
100
Ecosystem diversity
- A measure of the diversity of ecosystems that exist in a given region
○ A greater number of healthy and productive ecosystems results in a healthier environment overall
101
Species' richness
- The number of species in a given area
○ Used to measure biodiversity in a given area
102
Species' evenness
- The relative proportion of individuals within the different species in a given area
○ Tells us whether a particular ecosystem is numerically dominated by one species or whether all of its species have similar abundances
103
Microevolution
Evolution below the species level
104
Macroevolution
Evolution that gives rise to new species, genera, families, classes, or phyla
105
Mutation
- A random change in the genetic code produced by a mistake in the copying process
○ Mutations can affect an organism's survival and make their chances better or worse
106
Recombination
- The genetic process by which one chromosome breaks off and attaches to another chromosome during reproductive cell division
○ Does not create new genes but brings together new combination of alleles on a chromosome and therefore can produce novel traits
107
Artificial selection
The process in which humans determine which individuals breed, typically with a preconceived set of traits in mind
108
Natural selection
The process by which the environment determines which individuals survive and reproduce
109
Gene flow
- The process by which individuals move from one population to another and thereby alter the genetic composition of both populations
○ Alters the frequency of alleles in populations
○ Can bring in genetic diversity to a population that lacks it
110
Genetic drift
A change in the genetic composition of a population over time as a result of random mating
111
Bottleneck effect
- A reduction in the genetic diversity of a population caused by reduction in its size
○ When a population is reduced, its genetic diversity reduces as well
○ Can causes individuals to be less equipped to face environmental problems, disease, or low fertility
112
Founder effect
A change in the genetic composition of a population as a result of descending from a small number of colonizing individuals
113
Regulating services
Natural ecosystems help to regulate environmental conditions
114
Support systems
- Natural ecosystems provide several support systems that would be very costly for humans to generate
○ Ex: The pollination of food crops and natural pest control services
115
Resilience
- Ensures an ecosystem will continue to exist in its current state
○ Depends greatly on species diversity
116
Cultural services
Ecosystems provide beauty that many people are willing pay for
117
Theory of island biogeography
- A theory that demonstrates the dual importance of habitat size and distance in determining species richness
○ Depends on habitat size and distance from mainland
118
Range of tolerance
The limits to the abiotic conditions that a species can tolerate
119
Fundamental niche
The suite of abiotic conditions under which a species can survive, grow, and reproduce
120
Realized niche
The range of biotic and abiotic conditions under which a species actually lives
121
Distribution
- Areas of the world in which a species lives
○ Realized niche helps us understand the distribution of a species
122
Mass extinction
- A large extinction of a species in a relatively short amount of time
○ 5 mass extinctions have occurred over Earth's history
123
6th mass extinction
During the last 2 decades, scientists have stated that we are currently experiencing a sixth mass extinction of a magnitude within the range of the previous 5 mass extinctions due to human activities
124
Geographic isolation
Physical separation of a group of individuals from others of the same species
125
Allopatric speciation
The process of speciation that occurs with geographic isolation
126
Sympatric speciation
The evolution of one species into two, without geographic isolation
127
Reproductive isolation
The result of two populations within a species evolving separately to the point that they can no longer interbreed and produce viable offspring
128
Polyploidy
The heritable condition of possessing more than two complete sets of chromosomes
129
Primary succession
Succession that starts with an essentially lifeless area where there is no soil or bottom sediment in an aquatic area
130
Pioneer species
The first organisms to colonize a barren or disturbed area
131
Secondary succession
The process of ecological change that occurs after a disturbance, such as a fire or clear-cutting, where an existing community is destroyed but the soil remains intact
132
Keystone species
A plant or animal that plays a critical role in maintaining the structure and function of an ecosystem
133
Indicator species
Organisms whose presence, absence, or abundance can provide information about certain environmental conditions or changes
134
Invasive species
animals or plants from another region of the world that don't belong in their new environment
135
Species adaptation
The process by which a species changes over time in response to its environment, allowing it to survive and reproduce successfully
136
Selective pressures
Environmental factors that influence which individuals within a population are more likely to survive and reproduce
137
Trophic cascade
Occurs when predators limit the density and/or behavior of their prey and thereby enhance survival of the next lower trophic level
138
Niche generalist
- A species that can live under a wide range of abiotic or biotic conditions
○ Fare better under changing conditions
139
Niche specialist
- A species that is specialized to live in a specific habitat or to feed on a small group of species
○ More vulnerable to extinction from habitat changes
140
K-selected species
- A species with a low intrinsic growth rate that causes the population to increase slowly until it reaches carrying capacity
○ Large mammals and most birds are K-selected species
141
r-selected species
- A species that has a high intrinsic growth rate, which often leads to population overshoots and die-offs
○ These species reproduce often and produce many offspring
○ Small organisms are r-selected species
142
Survivorship curves
Graphs that represent the distinct patterns of species survival as a function of age
143
Type I survivorship curve
A pattern of survival over time in which there is a high survival throughout most of the life span, but then individuals start to die in large numbers as they approach old age
144
Type II survivorship curves
A pattern of survival over time in which there is a relatively constant decline in the survivorship throughout most of the life span
145
Type III survivorship curve
A pattern of survival over time in which there is low survivorship early in life with few individuals reaching adulthood
146
Carrying capacity (K)
The maximum population of a particular species that a given habitat can support over a given period
147
Density-independent factors
A factor that has the same effect on the individual's probability of survival and the amount of reproduction at any population size
148
Density-dependent factors
A factor that influences an individual's probability of survival and reproduction in a manner that depends on the size of the population
149
Limiting resource
A resource that a population can't live without and that occurs in quantities lower that the population would require to increase in size
150
Population growth rate
The number of offspring an individual can produce in a given time period, minus the deaths of the individual or its offspring during the same period
151
Instrinsic growth rate (r)
The maximum potential for growth of a population under ideal conditions with unlimited resources
152
Exponential growth model
- A growth model that estimates a populations future size after a period of time based on the intrinsic growth rate and the number of reproducing individuals currently in the population, without considering limiting factors
□ This model produces a J-shaped curve
□ Exponential growth is a density-independent factor
153
Logistic growth model
- A growth model that describes a population whose growth is initially exponential, but slows as the population approaches the carrying capacity of the environment
□ This model produces a S-shaped curve
□ Logistic growth is a density-dependent factor
154
Overshoot
When a population becomes larger than the environment's carrying capacity
155
Die-off
A rapid decline in a population due to death
156
Total fertility rate (TFR)
Average number of children each woman will have
157
Replacement fertility rate
- The total fertility rate for a nation that would keep its population stable
○ For most nations, this number is 2.1%
□ Greater number = increase ; lesser number = decrease
158
Crude birth rate
births per 1,000 individuals/year
159
Crude death rate
deaths per 1,000 individuals/year
160
Global population growth rate
(CBR - CDR)/10
161
National growth rate
[(CBR + immigration) - (CDR + emigration)]/10
162
Doubling time
- When a population grows exponentially and the number of years it takes for it to double
○ 70 / % growth rate
163
Rule of 70
- n = 70/R
○ R = growth rate
164
Factors that influence human population
* Population size
* Birth/death rates
* Fertility
* Life expectancy
* Migration
165
Population growth characterisitics of developing countries
○ Higher fertility, infant mortality, and death rates
○ Lower life expectancy
○ Low per capita resource use
166
Population growth characteristics of developed countries
○ Lower fertility, infant mortality, and death rates
○ Higher life expectancy
○ High per capita resource use
167
Factors affecting life expectancy, infant mortality and child mortality
* Available health care/prenatal care
* Adequate food supply
* Portable drinking water
* Good sanitation
* Moderate to low levels of pollution
168
Factors affecting life spans (gender)
* Gender-specific diseases
* Hazardous lifestyle choices
* Wars
* Dangerous jobs
169
Theory of demographic transition
The theory that as a country moves from a subsistence economy to industrialization and increased affluence, it undergoes a predictable shift in population growth
170
Stage 1 of demographic transition
○ CBR = CDR
○ Short life expectancy, high infant mortality
○ US/Europe = before 18th century
○ No countries in stage 1 now
171
Stage 2 of demographic transition
○ Death rates decline
○ Fertility rates remain high -> imbalance
○ US = early 19th century ; India = now
172
Stage 3 of demographic transition
○ # of births decline -> more birth control available
○ CBR = CDR again
○ Economy/education improves
173
Stage 4 of demographic transition
○ CBR < CDR
○ High affluence/economic development
○ More elderly
○ Government may encourage immigration or gives incentives to have more children
174
Three stages of age structure
○ Pre-reproductive
○ Reproductive
○ Post-reproductive
175
Theory of plate tectonics
The theory that pieces of Earth's lithosphere are in constant motion, driven by convection currents in the mantle
176
Convergent plates
- Two tectonic plates collide or come together
- Causes mountains, volcanic activity, and earthquakes
- Ex: Mariana Trench
177
Subduction
One tectonic plate moves beneath another plate at a convergent boundary, resulting in the recycling of old crust back into the Earth's mantle
178
Divergent plates
- Two tectonic plates move away from each other, resulting in the creation of new crust as magma rises to fill the gap
- Causes visible fault lines, rift valleys, seafloor spreading, volcanoes, and earthquakes
- Ex: Mid-Atlantic Ridge
179
Transform plates
- Two tectonic plates slide past each other horizontally
- Causes earthquakes
- Ex: San Andreas Fault
180
Soil horizons
- Distinct layers of soil that form as a result of various processes such as weathering, organic matter accumulation, and leaching
- Each horizon has unique characteristics that influence the movement of water, nutrients, and organisms within the soil
181
The process of soil formation
- Starts with parent material
- Over time, weathering occurs and the parent material is broken down into smaller and smaller particles
- Particles from other places might be introduced through the deposition
- Once a small layer of soil has been formed, moss and other small vegetation begin to grow
- With the presence of small vegetation and organisms, more soil horizons form and nutrients are added to the soil
- From here, the soil continues to develop as more plants and organisms interact with it
182
Soil erosion
- Often, soil can be washed away or eroded away by wind and water
- This happens when no plants or vegetation are available to hold the soil in place
183
Water quality and soil erosion
- Erosion can negatively impact water quality
- No soil or vegetation means that water won’t be filtered which might result in unclean water with higher amounts of pollutants
184
Water-holding capacity of soil
- The ability of a soil to retain water for plant use
- Particle size and amount of organic matter are significant factors in water-holding capacity
185
Porosity
- The measure of how much empty space, or pores, there is in a material such as soil or rock
- Indicates the ability of a substance to hold and transmit fluids
186
Permeability
- How easily fluids can flow through a material such as soil or rock
- Measures how well interconnected the pores are within a substance
187
Fertility
- How well-suited soil or land is for supporting plant growth
- Depends on the presence of essential nutrients, organic matter, and other factors that promote healthy plant development
188
Chemical properties of soil
- Soil pH
- Cation exchange
189
Soil pH
The measurement of acidity or alkalinity in soil
190
Physical properties of soil
- Aeration
- Soil compaction
- Permeability
- Particle size
191
Aeration
The ability of soil to take in essentials like nutrients, water, and oxygen
192
Soil compaction
- How compacted the soil particles are
- This can affect porosity, permeability, and aeration given space between individual particles
193
Biological properties of soil
Determined by the organisms and plants that live in it
194
Soil texture triangle
- A graphical tool used to classify different types of soils based on their proportions of sand, silt, and clay particles
- Follow the lines of each particle based on percent
- The point where the lines intersect is the type of soil it is
