topic four Flashcards
(103 cards)
1
Q
what is a species
A
a group of genetically similar living organisms that are able to interbreed and produce fertile offspring. Fertile offspring are those which can in turn interbreed and pass on their genes to another generation.
2
Q
population
A
A group of organisms of the same species that live in a particular area at the same time.
3
Q
community
A
A group of populations living and interacting in a particular area.
4
Q
ecosystem
A
A community and its abiotic environment.
5
Q
abiotic factors
A
Non-living factors, such as pH, salinity, wind speed, type of soil, etc.
6
Q
biotic factors
A
Living factors in an ecosystem, such as the plants and animals.
7
Q
autotroph
A
Organisms that are capable of making their own complex organic molecules from carbon dioxide and other simple compounds are called autotrophs
8
Q
heterotroph
A
Organisms that obtain their organic compounds through feeding on other organisms are called heterotrophs.
9
Q
consumers
A
organisms that gain nutrients by feeding on other organisms using ingestion or absorption.
10
Q
primary consumers feed only on
A
autotrophs
11
Q
secondary consumers feed on
A
primary consumers
12
Q
teritary consumers feed on
A
secondary consumers
13
Q
omnivores
A
consumers who feed on both producers and consumers.
14
Q
detritivores
A
heterotrophs that obtain their organic nutrients from detritus, which is waste or other organic debris, by internal digestion.
15
Q
internal digestion
A
the process by which an organism digests its food inside of its body, usually with the aid of a digestive tract.
16
Q
saprotrophs
A
organisms that get their nutrients by secreting digestive enzymes into their environment to break down organic debris around them.
17
Q
extracellular digestion
A
the process by which organisms secrete enzymes into their environment to break down organic debris around them.
18
Q
ecology
A
the study of relationships between living organisms and their interactions with their environment
19
Q
mutualism
A
symbiotic rel where both parties benefit
20
Q
commensalism
A
where one organism benefits and the other is unaffected
21
Q
parasitism
A
when one organism benefits and the other is harmed
22
Q
A predator-prey relationship is one in which
A
one organism hunts and feeds on another.
23
Q
community
A
a group of populations of different species living in the same area and interacting with each other.
24
Q
nutrient cycle
A
25
advantages of mesocosms
Treatments are easily replicated.
The effect of several environmental factors can be tested.
Food webs can be established.
Direct and indirect effects can be studied.
Contamination influence can be evaluated.
Constants can be controlled to see the effect of one environmental factor at a time.
The sustainability of an ecosystem can be tested
26
what does chi quared test
how likely it is that an observed distribution is due to chance. categorical data only
27
what is the null hypothesis
the hypothesis that states that there is no association between the two populations being tested in the chi-squared test.
28
The ecological frequency is
the number of times a plant species occurs in a given number of quadrats. Frequency is usually expressed as a percentage and is sometimes called a Frequency Index.
29
expected frequency is calculated y
multiplying the row total by column total and dividing by the grand total
Row total×Column total/Grand total=Expected frequency
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expected frequency
the number of quadrats a population is expected to occupy in an area.
31
chi squared formula
x2=Σ(O−E)^2/E
Χ 2 = the test statistic
∑ = the sum of
O = Observed frequencies
E = Expected frequencies
32
X 2 calculated >X 2 critical:
H 0 is rejected and the variables are associated
33
X 2 calculated ≤ X 2 critical:
H 0 is accepted and the variables are not associated
34
quadrat
a tool used to measure population distribution in a given area. It is often made in a square shape.
35
random sampling
necessary in order to obtain data that is random and unbiased.
36
The energy that is contained in the carbon compounds consumers ingest is used for the following cellular activities (this is not a complete list):
Nucleic acid and protein synthesis
Ion exchange across membranes
Cell division for reproduction, growth and repair
Movement of components within cells.
37
how is atp generally produced
by oxidising, or breaking down, glucose and other carbon compounds through the process of respiration
38
food chain
a model that shows how nutrients and energy are passed from producer to primary consumer, then secondary consumer, and so on. It clearly shows how each organism in the chain gets its food as well as the direction the energy flows through the chain. Food chains generally begin with plants and end with animals.
39
which way do the arrows point in food chains
direction of nutrient and energy flow
40
food web
shows the interconnections that exist among food chains. In a food web, each organism may have several sources of nutrition, or may be a source of nutrition for several other organisms.
41
how is energy lost in food chains
bones not eaten
fur not eaten
faeces
heat
42
The energy transfer between each trophic level is estimated to be around ??? to account for energy lost to the environment through movement, excretory products, faeces, heat and unconsumed materials.
10 to 20%
43
An energy pyramid is a model used to
represent the energy flow in a community.
44
key difference in eenrgy flow and nutrient cycle
energy must be in constant supply from the sun, but nutrients are only found on Earth and in finite amounts
45
carbon dioxide combines with water to form
carbonic acid
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carbonic acid
the molecule that forms when CO2 combines with water. This molecule is unstable and dissociates easily in water into hydrogen ions (H+) and hydrogen carbonate ions (HCO3-). The H+ that are released in this dissociation lower the pH of the water (makes it more acidic).
47
stomata
pores found on the underside of leaves which allow for gas exchange. Aquatic plants are adapted to have stomata on the upper side of their leaves for gas exchange.
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leaf
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anerobic conditions
environmental conditions that lack oxygen for aerobic respiration. Also, known as anoxic conditions.
50
methane
a carbon molecule which is produced in anoxic conditions and can oxidise into carbon dioxide and water.
51
how is methane produced
from organic matter under anaerobic conditions (meaning organisms that live without oxygen) by methanogenic archaeans (single-celled prokaryotes). These bacteria are found in several anoxic (without oxygen) environments, for example, wetlands, such as swamps, marshes, and bogs, as well as lake beds, the guts of ruminants, termites and landfill sites. Once formed, methane may either diffuse into the atmosphere or accumulate in the ground.
52
Methanogenic archaeans –
bacteria that are found in several anoxic environments and produce methane as part of the carbon cycle.
53
ruminants
mammals that have a mutualistic relationship with methanogenic archaeans that help them to digest cellulose from the cell walls in the plants they eat. This creates methane, which is released as gas from the mammal.
54
how do ruminants produce methane
Ruminants chew on plants breaking down the molecules, such as some carbohydrates, into smaller monomers (using their saliva) by the process of hydrolysis.
Organic matter is first changed to organic acids and alcohol, such as ethanol, by a group of bacteria in a process called acidogenesis.
Other bacteria then convert these organic acids and alcohol into acetate (through acetogenesis), carbon dioxide and hydrogen.
Finally, methanogenic bacteria can produce methane either through the reaction of carbon dioxide and hydrogen (1) or through the breakdown of acetate (2), also known as methanogenesis.
55
hyrdolysis
the chemical process of breaking large polymers into dimers or monomers using water.
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acidogenesis
the chemical process in which bacteria convert organic matter into organic acids and alcohol.
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acetogeneiss
the chemical process in which bacteria convert organic acids and alcohol into acetate.
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methanogenesis
the chemical process in which methanogenic bacteria can produce methane through the reaction of carbon dioxide and hydrogen or through the breakdown of acetate.
59
peat formation
there are some waterlogged areas where the stagnant water creates an anaerobic (no oxygen present) environment in which the saprotrophs cannot grow. The result is an environment that becomes progressively acidified over time. Any surviving saprotrophs die, and the remaining organic matter is only partially digested. New layers of leaf litter and other organic debris fall on top of this older layer of material, further compressing it.
60
uses of peat
As a substitute for firewood for cooking and heating
To increase the moisture holding capacity of soil (that is rich in sand particles) in horticulture
To increase the water infiltration rate of soils rich in clay particles
To acidify soils for specific pot plants.
61
Methanogens are archaea that are:
Anaerobic organisms that obtain energy through the synthesis of methane from CO2 and H2 or acetate.
62
fossil fuels
organic material that has been compressed over time, to form coal, oil and gas.
63
combustion
a process of burning which releases CO 2 from organic material such as fossil fuels or biomass.
64
Name one type of fossil fuel that was formed at the bottom of lakes and oceans millions of years ago and can be found in porous rock.
oil
nautral gas
65
calcium carbonate
an important source of carbon in the environment which makes up shells and exoskeletons and can eventually become porous sedimentary rock such as limestone.
66
where does calium carbonate dissolve
acid but not alkaline
67
lithification
the process of compressing organic matter over a long period of time until it becomes rock.
68
For the formation of limestone rocks from the shells of molluscs and the exoskeleton of corals, the conditions should be:
slightly alkaline
69
reservoir
a place where a certain element, such as carbon, has accumulated or pooled. Also, known as a sink when discussing nutrient cycling.
70
flux
the process that moves an element from one reservoir or sink to another.
71
lithiosphere
the portion of the Earth that consists of the crust and upper mantle.
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biota
the portion of the earth that consists of the living organisms
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carbon cycle
74
For carbon, the cycling process involves:
A reservoir
An exchange pool
A biotic community
75
Greenhouse gases
gases found in the atmosphere such as water vapour, carbon dioxide, methane and nitrous oxides, that contribute to the greenhouse effect.
76
Water vapour –
water found in the atmosphere in a gaseous form. It is the most abundant greenhouse gas.
77
greenhoue gas proportions
78
in order for a gas to contribute to the greenhouse effect, it needs to be able to absorb what
longer wavelength radiation
79
which greenhouse gases contrribute more to the greenhouse effect
Methane (CH 4 ) and nitrous oxides (N 2 O and NO) are able to absorb longer wavelength or infrared radiation. They contribute to the greenhouse effect, but not as much as carbon dioxide and water vapour whciha re present in larger quantities.
methane traps 20 times more heat than the same amount of carbon dioxide; that is, methane causes faster warming of the planet.
80
what is the carbon dioxide equivalent / CO EQ
a term for describing different greenhouse gases in a common unit. For any quantity and type of greenhouse gas, CO 2 EQ signifies the amount of CO 2 which would have the equivalent global warming impact.
81
Why do some gases cause a greenhouse effect but not others?
The basic reason is that some gases, such as water vapour, carbon dioxide, methane, and nitrogen oxides can absorb longer wavelengths of light and re-emit them as heat.
82
radiation
energy that may be a subatomic particle, for example an electron (gamma rays) or in the form of an electromagnetic wave, for example ultraviolet radiation.energy that may be a subatomic particle, for example an electron (gamma rays) or in the form of an electromagnetic wave, for example ultraviolet radiation.
83
solar radiation
energy from the sun that comes in the form of electromagnetic waves. This includes many types of waves such as visible light or ultraviolet light.
84
ozone layer
O 3 – is a layer of the Earth’s atmosphere that protects the Earth from ultraviolet radiation coming from the sun. It is not considered a greenhouse gas because it does not absorb longwave radiation.
85
UV radiation
ultraviolet radiation is a type of shortwave radiation coming from the sun, but is filtered out by the ozone layer of the atmosphere.
86
long wavelength radiation
also known as infrared light, a type of radiation that is emitted from the Earth and its atmosphere. Examples include, microwaves and radiowaves.
87
short wavelength radiation
this type of radiation comes from the sun in the form of visible light and ultraviolet light. It is absorbed by the Earth and re-emitted as long-wavelength radiation.
88
infared
this type of long-wavelength radiation is given off from the Earth in the form of heat.
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global warming
the warming of the Earth and its atmosphere due to the intensified greenhouse effect.
90
the first step of the greenhosue efect: solar radiation
Sunlight contains different types of energy that travel as waves. These waves cover a range from very short to longer lengths. A part of sunlight, which we can see as colors, makes up about 44% of this energy.
When sunlight enters our atmosphere, a layer called the ozone layer stops some of the harmful radiation. This layer doesn't trap heat like greenhouse gases do. Only the short and not harmful waves from the sun can pass through this layer and reach the ground. Some of these waves bounce off the surface, but most get through the gases that surround our planet and reach the ground.
91
secnond step of the greenhosue effect
The Earth absorbs some of this shortwave radiation while some is reflected. This absorbed radiation is then re-emitted, mainly as infrared (heat) , which is a longwave radiation (with a peak around 10 000 nm).
part of this longer wavelength radiation escapes Earth’s atmosphere into space. However, much of it is absorbed by greenhouse gases in the atmosphere.
92
final step of greenhoue gas effect
The greenhouse gases re-emit the absorbed light in all directions as heat. Some of this radiation is re-emitted towards the Earth, thus contributing to global warming.
93
greenhoues effect
94
Why are oxides of nitrogen classed as greenhouse gases?
Oxides of nitrogen trap some of the longwave radiation emitted by the Earth’s surface.
95
impact of global warming
Climate change: Higher global averages mean that the total amount of water that evaporates from oceans and lakes increases. More water in the atmosphere leads to heavier rainfall. Global warming can also have substantial effects on wind and ocean currents causing stronger hurricanes and typhoons.
Rising seawater : Another consequence of the increased global temperature is the rising seawater temperature and the melting effect on the polar ice caps and glaciers around the world.
Loss of habitat : The polar ice caps and glaciers are melting, decreasing ice habitats for some arctic organisms. Also, when these ice caps melt they cause a rise in sea levels, as mentioned above, destroying coastal habitats.
Biotic factors : The warming of any habitat would change the species that live in the area and can cause changes to migratory patterns. Temperate species move into warmer arctic areas and compete with the arctic species. Arctic species need to adapt to competition and the change in temperature or emigrate to a new habitat. This would cause a change in the distribution of species, possibly a decrease in population sizes and, in extreme cases, extinction of species. As you learned in subtopic 4.2 , changes such as these could have severe impacts on the food chains of an ecosystem disrupting the food web and having a large impact on organisms in higher trophic levels. Other effects on the biota may be an increase in decomposition due to melting permafrost, which exposes saprotrophic bacteria to oxygen, releases methane, and, with an increase in temperature and moisture there will be an increase in pest species and pathogens.
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climate change def
changes in the long-term weather patterns in an area or region due to the intensified greenhouse effect.
97
precautionary principle
also known as the burden of proof, this principle states that even without concrete evidence of a causal relationship, precautionary measures should be taken to ensure that humans are not causing detrimental harm to the environment or human health.
98
coral reefs
a ridge in the ocean where living coral polyps attach and secrete calcium carbonate. Coral reefs are typically very diverse places found in warm shallow waters.
99
ocean acifdification
the drop in pH of the ocean due to the absorption of carbon dioxide, which forms carbonic acid. The H+ ions become dissociated from carbonic acid causing the water to become acidic.
100
calcification
the process used by molluscs, crustaceans, and corals to build their shells and exoskeletons using calcium carbonate.
101
What is the main cause of the dissolution of the calcium carbonate exoskeletons?
ocena pH has dropped
102
An increase in the concentration of dissolved carbon dioxide represents a threat for coral reefs because:
It will reduce calcification in corals and make them more brittle
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