Ch. 2 - Cycles of Matter (Excluding AP Content) Flashcards
(117 cards)
1
Q
What elements make up 95% of all living things?
A
Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus, Sulfur
2
Q
What happens to these elements that make up most of living things?
A
They are cycled through the biosphere so they are available to living things.
3
Q
What is the conversion of these elements of living things called?
A
Nutrient Cycling, and can be biotic or abiotic.
4
Q
Water comprises how much of all plant and animal tissue? How much of the human body? How much of this water must humans replace daily?
A
More than 50% of all plant and animal tissue.
The human body is around 70%.
We lose and replace 3% of our water.
5
Q
There is a limited amount of water in the biosphere. What happens to it so it doesn’t run out?
A
It has to be naturally recycled.
6
Q
What percentage of water exists in liquid form?
A
More than 97%.
7
Q
Water vapour is a greenhouse gas. What effect does it have on the planet?
A
Readily traps and transfers heat.
8
Q
What happens to water as it is recycled through the atmosphere?
A
Purified and made available to organisms.
9
Q
Water is also a product of cellular respiration. Water produced by cellular respiration is called what?
A
Metabolic water
10
Q
What are the six main components of the water cycle? What’s the water cycle’s alternative name?
A
- Condensation
- Precipitation
- Infiltration
- Surface run-off
- Evaporation
- Transpiration
AKA. the Hydrologic Cycle.
11
Q
In the water cycle, what is precipitation?
A
Any form of water that falls from the sky (rain, snow, hail, etc.)
12
Q
In the water cycle, what is infiltration?
A
Surface water becomes groundwater by moving down through the soil.
13
Q
In the water cycle, what is surface run-off?
A
When soil is infiltrated to full capacity, any excess water flows over the land.
14
Q
In the water cycle, what is condensation?
A
Water vapour returns to liquid form, either by saturation (dew) or in clouds by accumulating in large droplets.
15
Q
In the water cycle, what is evaporation?
A
Water ends up as a vapour in the atmosphere by evaporating from ponds, lakes, rivers, and oceans.
16
Q
In the water cycle, what is transpiration?
A
The movement of water through a plant and its evaporation from leaves, stems, and flowers.
17
Q
What is evapotranspiration?
A
Water vapour ends up in the atmosphere as a result of this: the combined evaporation and transpiration from a terrestrial area.
18
Q
Where is the majority of evaporation from?
A
86% from the ocean.
19
Q
What makes water so special?
A
Water has properties that make it an excellent carrier of dissolved material and other materials as well as an effective medium for transferring energy.
20
Q
What are the four (five) unique properties of water?
A
- Water is a universal solvent
- Water has a relatively high melting and boiling point
- Water has special cohesive and adhesive properties
- Water has a high heat capacity
(Most dense at 4 degrees Celsius)
21
Q
Why is water called the universal solvent?
A
As water moves from place to place or changes state, it carries a variety of substances with it. Some are beneficial, but others can be toxic.
22
Q
Chemically, a water molecule is?
A
Two hydrogen atoms covalently bonded to an oxygen atom.
But, it is polar and forms hydrogen bonds between the one slightly negative oxygen molecule and the slightly positive hydrogen molecules of nearby other molecules.
23
Q
What type of compounds does the structure and polarity of water allow it to do?
A
Dissolve a wide range of substances from molecular compounds such as CO2 to ionic compounds like NaCl -> Na+, Cl-
24
Q
Are individual hydrogen bonds strong?
A
No, they are relatively weak and in liquid water they break and reform constantly.
25
Despite the weakness of individual hydrogen bonds, why does water still have such a high melting and boiling point?
Many hydrogen bonds are very strong. These bonds must be broken in order for water to change from liquid to gas. Thus, lots of energy is required to boil water.
26
What property of ice (melting point) is influenced by hydrogen bonds?
It has a relatively high melting point.
27
Unlike most substances, water in its solid state has what property?
Solid water (ice) is less dense than water in its liquid state.
28
The hydrogen bonds in ice form what?
They hold water molecules in an open crystal structure.
29
Due to the open crystal structure of water, what happens to water as it freezes?
It expands.
30
As ice melts, what happens to the crystal structure?
It collapses and density increases.
31
At what temperature does water reach its highest density?
4 degrees Celsius. After that density decreases because of thermal expansion.
32
How do nutrients cycle in lakes in the spring?
1. Water becomes more dense as it warms until 4 degrees.
2. The denser water sinks
3. This leaves colder water at the surface to be warmed by the Sun
4. The colder water subsequently sinks
(repeat)
33
How do nutrients cycle in lakes in the fall?
1. Water becomes cooler towards 4 degrees Celsius
2. The cooler water becomes denser and sinks
3. This leaves warmer water on top
4. The warmer water cools and sinks until it reaches maximum density at 4 degrees Celsius.
34
As water sinks and rises, what happens to nutrients and oxygen?
Nutrients and oxygen are cycled with it.
35
How does water unlock nutrients? (Define percolation)
Water percolates into spaces in rocks and expands when it freezes, weathering rocks to create sand and soil and nutrients in the process.
"Break up"
36
What is the role of ice floating on top of the lake?
They insulate the water and keep it from freezing to the bottom.
The bottom is often warmer because of radiating ground heat.
37
What is cohesion?
Attraction of water molecules to each other, is responsible for surface tension.
Surface tension helps organic debris on top of the water where they provide nutrients for aquatic organisms.
Ex: For water striders
38
What is adhesion?
Attraction of water molecules to other substances.
Water molecules are attracted to the inner surface of a tree's xylem tissue, providing an upward force to help move water from the roots to the leaves.
39
What happens as a result of the hydrogen bonding in water to its heat capacity?
This results in a high heat capacity, meaning that it requires large amounts of energy to cause small temperature changes
Water heats up more slowly and holds heat longer than almost any other liquid.
40
How does water's high heat capacity affect living organisms like us?
Because living organisms have a large concentration of water in their tissues, water's high heat capacity allows them to maintain a fairly consistent internal temperature.
41
What does water's high heat capacity have on climate?
Bodies of water have a moderating effect on air temperature over nearby land.
42
How is heat transferred near the equator?
Near the equator, large amounts of heat energy heat the ground, causing evaporation. Evaporated water rises and moves towards the poles, distributing its heat as it cools. Process distributes heat away from the equator.
43
What are ocean currents and what do they do?
These transfer warm water to cooler regions. The warm water heats air and moderates temperatures over nearby land. Have a large impact on climate.
44
What were Canada's two largest water-related natural disasters?
Droughts in the 1930s and the 1980s.
45
If global temperatures rise, what happens to water?
Rate of evaporation increases.
Plants closes stomata, less CO2 taken, less photosynthesis, more CO2.
46
What causes our increased demand for water? What does it cause?
The increased demand for water caused by population and industrial growth would put Alberta's rich supplies of fresh water in danger.
47
What are biogeochemical cycles?
The routes that chemical nutrients takes through the biotic and abiotic components of the biosphere.
48
What do producers, such as plants, require?
Matter to build cell structures and provide energy.
49
What does the recycling of matter through the ecosystem allow?
Both autotrophs and heterotrophs to obtain essential nutrients.
50
At each step in a biogeochemical cycle, where are substances temporarily stored?
Nutrient reservoirs, such as organisms, soil, water, and air.
51
How does the time in which substances are stored in reservoirs vary?
Some substances are stored for a certain period of time, while other substances move through the environment from reservoir to reservoir.
52
What is rapid cycling? Example.
Substances that cycle quickly between nutrient reservoirs.
For example, breathing. The atmosphere. Or, the top layer of the ocean.
53
What is slow cycling? Example.
Some substances accumulate and are stored for long periods of time in nutrient reservoirs.
For example, fossil fuels, coal/oil which are carbon reservoirs formed over millions of years. Or, the deep ocean.
54
What is the carbon the key element in?
Organic compounds, since it forms chains with itself; can form almost limitless numbers of compounds.
55
Which is more, the plant consumption or the plant emission of carbon dioxide?
They consume billions of tons of C in the form of CO2 each year. This is much more C than animals/plants release during cellular respiration.
56
What does much of the carbon released into the atmosphere come from? Related to plants.
Forest fires and decocmposition of organic matter by decomposers.
57
How is inorganic CO2 converted? To what?
To an organic form (sugar) through photosynthesis.
58
After the CO2 conversion to sugar, what is sugar converted to?
All other organic compounds (starch, amino acids, proteins, fats)
59
Carbon is stored where?
Long term, in plants. Also, the largest is the ocean (ocean absorption).
A carbon sink is a natural or artificial process that "removes CO2 from the atmosphere".
60
What do trees and forests act as?
Carbon sinks, absorbing and storing much more carbon than they emit. Carbon is only released when a tree dies and decomposes or is combusted.
61
How much carbon emissions does deforestation account for?
The release of about 2 gigatonnes of carbon into the atmosphere per year.
62
What role do photosynthetic organisms in the ocean, like plankton and algae, play in the slow cycling of carbon?
Reproduce rapidly large amounts of biomass and incorporate carbon into their structures.
63
What happens to the carbon in biomass?
It is consumed by heterotrophs but a small % drifts to the ocean floor. Over millions of years, it may be incorporated into rocks or turned into fossil fuels.
64
How do human activities influence the slow cycling of carbon?
The combustion of fossil fuels rapidly releases carbon back into the atmosphere.
Since the Industrial Revolution, CO2 levels in the atmosphere have increased by 30%.
65
How is sulfur important to organisms?
All organisms require sulfur, and play an important part of proteins and vitamins.
66
How do plants and algae use sulfur?
In the form of sulfate (SO4 2-), which readily dissolves in water.
67
How is sulfur incorporated into plants and algae?
Is incorporated into their cells and tissues. When they die, decomposers quickly return the sulfur to the soil and the atmosphere.
68
Bacteria play a major role in the sulfur cycle. Different types have different roles. What are the two types and how do they interact with each other?
- Sulfate reducers
- Sulfur oxidizers
The waste generated by one type of bacteria is required by another (i.e. Winogradsky Column)
69
What is the role of sulfur reducers?
Convert:
Sulfate to Sulfide
70
What is the role of sulfur oxidizers?
Convert:
Sulfide to elemental sulfur, and then to sulfate.
71
Do sulfur compounds stay in the atmosphere long, and why?
No, because rain and snow return the sulfur to the Earth's surface where it is eventually used by plants, algae, and bacteria.
(Acid rain)
72
What is acid deposition?
Term used to describe sulfurous compounds returning to the ground from the air, since sulfates and sulfur dioxide dissolves in water.
(Acid rain, which lowers pH and causes erosion)
73
How do volcanic activity and human industries impact the sulfur cycle?
It distributes sulfur into the air, soil, and water.
74
What is the main player in the nitrogen cycle?
Bacteria.
Lightning also turns N2 to nitrate (nitrification).
75
How much of the Earth's atmosphere by volume does nitrogen make up?
78.1%, and is the main nitrogen reservoir
76
Why is nitrogen essential to organisms? How do humans get nitrogen?
An essential part of proteins and DNA.
Through our diet since N2 can’t diffuse into lungs.
77
Why isn't elemental nitrogen used?
Most organisms cannot use atmospheric nitrogen.
78
What forms of nitrogen can plants use?
NH4 (ammonium) and nitrate.
79
What is nitrogen fixation?
Some bacteria can convert N2 gas into ammonium (NH4) in this process.
Ex: Lumpy nodules on roots of legumes like clover containing nitrogen-fixing bacteria. They convert N2 to NH4 which is shared with the plant, In return, plants give bacteria sugar from photosynthesis.
80
What is ammonification?
NH4 is also produced when decomposers break down organic matter.
81
What is nitrification?
Where the soil bacteria convert NH4 to NO2 (nitrite) and then to NO3 (nitrate).
Also, lighting converting N2 to nitrate.
Plants can use nitrate (NO3) as a nitrogen source.
82
What is the order in which the nitrogen cycle goes through?
Nitrogen fixation, nitrification, ammonification, assimilation (dissolve into tissues), denitrification.
83
What is denitrification?
Completes the cycle by converting nitrite and nitrate back into N2 gas.
This process is done by denitrifying bacteria and occurs when there is very little oxygen.
84
Summarize the nitrogen cycle.
1. Nitrogen gas (N2) is removed from the atmosphere via nitrogen-fixing bacteria, converting it to ammonium (NH4), which plants can use.
N2 -> NH4 (nitrogen fixation)
2. NH4 is also produced when decomposers break down organic matter via AMMONIFICIATION.
3. Bacteria convert NH4 into nitrite (NO2), then nitrate (NO3), which plants can also use. (Nitrification) And lightning.
NH4 -> NO2 -> NO3
4. Denitrifying bacteria then complete the cycle by converting nitrite or nitrate back into nitrogen gas via DENITRIFICATION (NO3 OR NO2 -> N2)
85
Why is phosphorous significant to organisms?
Phosphorous is a part of DNA, cell membranes, and ATP (energy carrier molecule that is essential to all cells) AND a major component of bones and teeth.
86
What makes the phosphorous cycle different?
It does not cycle through the atmosphere.
Doesn’t become a vapour.
87
Where is phosphorous found in?
Soil and water. Rocks have phosphate. Animals absorb phosphates by eating plants or plant-eating animals.
(From infiltration and run-off)
88
How do consumers obtain phosphorous?
Consuming foods like milk, grain, and meat.
89
What form of phosphorous can producers only obtain?
Producers can only obtain phosphorous in the form of phosphate (PO4), which is water soluble.
90
What does the scarcity of phosphorous cause?
Keeps the growth of producers in balance.
91
What are algal blooms?
The overgrowth of algae.
Produces large amounts of organic material.
As decomposers break down this material, they use up O2 in the water, resulting in the death of fish and other aquatic organisms.
92
What causes algal blooms?
Excess phosphorous, NOT nitrogen.
This is why phosphates are banned in soaps and detergents.
93
How does algal bloom occur?
1. Excess phosphorous enters the aquatic ecosystem
2. Algal bloom and overgrowth occurs
3. Sunlight cannot penetrate below the surface
4. Plants below the surface cannot photosynthesize and die.
5. The decomposer population grows quickly, depleting O2.
6. Fish and other organisms requiring oxygen die.
94
What is eutrophication?
The general term describing the process by which a body of water acquires a high concentration of sediments and nutrients, especially phosphates and nitrates.
Some typically promote excessive growth of algae.
95
As the algae die and decompose, high levels of what do what to the water?
Organic matter and the decomposing organisms deplete the water of available oxygen, causing the death of other organisms, like fish.
96
How fast does eutrophication take and what influence do humans have on it?
Eutrophiciation is a natural, slow-aging process for a water body BUT human activity greatly speeds up the process (with fertilizers, etc.)
97
What is hypoxia?
The condition in which dissolved oxygen is below the level necessary to sustain most animal life.
98
What is oligotrophic?
Opposite of eutriophic.
A lake/pond that has low levels of nutrients and high levels of dissolved oxygen. Often in mountains.
99
What is productivity? What is it measured in (there are two things)? What does it measure then?
The rate at which an ecosystem's producers capture and store energy within organic compounds.
Measured in terms of energy per unit area, per year (J/m^2/A) OR expressed as the biomass of vegetation, added per area, per year (g/m^2/A).
(A = annum = year)
Thus, it is the rate at which new biomass is produced NOT A MEASURE OF TOTAL BIOMASS.
Producitivty increases = better photosynthesis, for example.
100
In general, what two things limit a region's productivity?
The amount of solar energy and productivity also depend on moisture.
(Climate)
101
What is homeostasis?
Maintaining a state of equilibrium.
102
How does life itself maintain homeostasis in the biosphere?
Life itself plays a vital role in maintaining the conditions of the biosphere that allow organisms to survive.
Scientists believe that if life had never existed on Earth, the atmosphere would be 98% CO2 and the oceans 13% salt.
103
What was the composition of Earth before humans?
Stromatolites that contain black bands of iron oxides must have formed when free iron ions
and dissolved oxygen were found in the oceans. As oxygen produced by photosynthesis built
up, it would have become bound to the oceans’ store of iron ions until there were no more free
ions. At this point, the black bands in stromatolites would have stopped forming, as there were
no more free ions in the water. Additional oxygen gas from photosynthesis would have escaped
into Earth’s atmosphere. If Earth’s atmosphere had always contained oxygen, presumably the
black bands of iron oxides would have formed earlier as atmospheric oxygen was mixed with
ocean water, forming iron oxides.
- Scientists think that the sudden increase in oxygen 2.5 billion years ago was mostly due to the activity of photosynthetic cyanobacteria (though these are more toxic than algae).
104
What are stromatolites?
Micro-organism cells pile up that form sedimentary rocks.
105
What is cyanobacteria?
The first photosynthetic bacteria.
106
Why is it hard to replicate the Earth's biosphere? What are some ongoing projects?
The balance of energy and matter exchange in the Earth's biosphere depends on extremely complex systems.
- Biosphere 2
- NASA Advanced Life Support (ALS) Program
- NASA Haughton-Mars Project
107
What was the result of Biosphere 2?
Functioned for several months, but O2 levels eventually dropped, as CO2 levels increased to unsafe levels.
108
What is the NASA Advanced Life Support (ALS) Program?
Research how plants may be grown in a space colony for food and O2 regeneration, and research how to convert waste to usable resources.
109
What is the NASA Haughton-Mars Project?
Situated in the Arctic is a self-situated environment used to simulate a possible colony on Mars.
110
What are dead zones?
Regions in lake/oceans where life has suffocated due to algal blooms. There are approximately 150 dead zones in oceans, ranging in area from 2.6 to 100 000 km^2.
111
What are algal blooms and their more complex causes?
Can occur seasonally in response to the turnover of nutrient-rich waters in warmer temperatures.
However, pollution can also cause blooming:
- Nutrients in soil exposed by deforestation washed into rivers by rain
- Sewage discharged into bodies of water carry large amounts of phosphate and nitrate
- Run-ooff can carry fertilizer and manure from fields/lawns to rivers, lakes, and oceans.
112
Why is wetland destruction a significant issue?
- Wetlands act as large water filters
- Many wetlands have been drained to make room for agricultural + urban growth.
For example, wetlands in East Calcutta, India.
113
What are some examples of far-reaching consequences (6) of our impact to the biosphere?
- Ecologists discover that biogeochemical cycles are **linked in unexpected ways**
- Transfer of matter through the biosphere is closely **linked to the transfer of energy** through the biosphere
- Effects of disruptions to natural cycles in the biosphere are **difficult to predict**
- Out tap water may contain water molecules **once transpired by a tree in a tropical rainforest**
- **Fertilizers** applied to lawns may find their way into a distant waterway, causing a **dead zone**
- Satellite data and computer modelling are helping scientists **better understand what keeps the transfer of energy and cycles of matter in balance** and the biosphere hospitable to life.
Ex: Moulins (holes) in Greenland Ice Caps
114
Which two cycles do humans have most impact on?
Carbon and sulfur cycle.
115
Why can overapplying pesticides be bad?
Kill of important pets to the soil (beneficial) and thus the soil structure.
116
What is the form of carbon in the ocean?
38000 GT in dissolved CO2 and 11000 GT in ocean floor as methane hydrates.
117
What type of stone contains carbon?
Calcium carbonate, coming from shells of aquatic organisms. As limestone weathers, small amount of carbon releases back to the soil, air, and H2O.
