Topic 5 Flashcards
(116 cards)
1
Q
What is the biosphere?
A
The part of earth inhabited by living organisms
2
Q
What is organic matter?
A
- proteins, triglycerides, polysaccharides and nuclei acids
- will be broken down via hydrolysis into soluble monomer units
3
Q
Describe abiotic
A
An ecological factor that is part of the non-living or physical environment of an organism
4
Q
Describe biotic
A
An ecological factor that is part of the living environment of an organism
5
Q
Describe autotroph
A
An organism that builds up the organism molecules it requires from small inorganic molecules
- AKA producers
6
Q
Describe heterotrophs
A
An organism that gains its nutrients by feeding on other organisms
- break down complex organic molecules and then will build up the organic molecules it needs
- AKA consumers
7
Q
Describe producer
A
An organism that can make its own organic compounds from inorganic compounds
- start of all food chains
8
Q
Describe primary consumer
A
An organism that consumes plant material for its food
- herbivore
9
Q
Describe secondary consumer
A
An organism that feeds on primary consumers
- carnivore
10
Q
Describe predator
A
An organism that kills another organism before eating it
11
Q
Describe trophic level
A
The position an organism occupies ina food chain
12
Q
Describe decomposer
A
A microorganism that lives by breaking down organic compounds in dead material and other waste products into carbon dioxide, water and mineral ions
- release digestive enzymes
- bacteria and fungi
- specialist heterotrophs
13
Q
Describe detritivore
A
A primary comsumer that feeds on dead organic matter called **detritus
- complex organisms
- digestive enzymes inside
14
Q
Describe food chain
A
A sequence that represents the way in which energy is transferred from one organism in a community to another
15
Q
Define ecosystem
A
A community of living organisms and their physical environment in an area, which is self-sustaining
16
Q
Define habitat
A
The environment with a distinct set of conditions where a species or a group of species live
17
Q
Define community
A
Populations of living things interacting with each other in a habitat or ecosystem
18
Q
Define population
A
A group of interbreeding organisms of the same species living together in the same area at the same time
19
Q
Give examples of abiotic factors
A
- temperature of air,soil and water
- humidity
- edaphic (soil) factors
-composition
-compaction
-pH, moisture - water availability
- air quality
- light intensity
- wave action
- pollution
- natural disasters
- mineral ion conc.
- rainfall
- space
- topography (landscape)
- climate
- water O2 content
- wind speed and direction
- altitude
- gradient
- aspect (direction)
- salinity
20
Q
Give examples of biotic factors
A
- competition -Interspecific/intraspecific
- mutualism
- Parasitism
- trampling
- population size
- species pop. Size
- human interference
21
Q
What is intraspecific competition
A
Competition within species
22
Q
What is interspecific competition
A
Between species
23
Q
What are anthropogenicfactors
A
Factors caused by humans
24
Q
Define niche
A
The role on organism plays ina habitat
25
Define succession
A sequence of changes in a community over a period of time
- community/organisms/species/plants
26
Describe primary succession
- no soil at start
- newly formed habitat
27
Describe pioneer phase/colonisation
- no soil- bare land
- pioneer species
-algae,lichen,mosses- will produce soil and add organic content
-extreme conditions
- no organic content
- ow species richness
The pioneer species will grow first and produce soil and this will allow shallow plants to grow
28
Describe development phase
- soil content continues to. Increase and organic material increases
- larger plants, primary/secondary consumers - ecosystem formed
- less extreme conditions
- increasing species richness
Larger plants/animals will outcompete _____ for ______
29
Describe climactic community phase
- self-sustaining
- dominant species - trees
- species richness may decrease
- high species richness
- remains unchanged and stable
30
What is a dominant species
The largest most abundant plant species
31
Define climax community
The final stage/sere of succession
- stable, self-sustaining, dominant species
32
Describe a secondary succession
Happens when an existing community has been cleared
- starts with soil and pioneer species
- succession will occur more rapidly
- will result in a different CC than the previous
33
Describe deflected succession
When a community remains stable only because of human prevention
- plagioclimax reached
- anthropogenic
34
Define primary productvity
the rate at which energy is incorporated into organic molecule in an ecosystem
35
what are photosythetic autotrophs
organisms that make their own organic compounds from inorganic compounds using **light**
light energy -> chemical energy
36
what are chemosynthetic autotrophs
organisms that make their own organic compounds from inorganic compounds using **energy from chemical reactions**
37
what is the equation for photosynthesis
6CO2 + 6H2O --> C6H12O6 + 6O2
in the presence of chlorophyll and light
38
what is **photolysis**
using energy from sunlight to split the stron OH bonds in water
H2O --> 2H+ + 2e- + 0.5O2
39
what happen to the hydrogen ions produced in photolysis
reacts with CO2 to 'store' yhe hydrogen as **glucose**
40
how is glucose used
- store as starch
- creates organic molecules
- (aerobic) respiration
41
name the parts of a chloroplast
- thylakoid membrane
- thylakoid space
- granum
- stroma
- loop of DNA
- starch grain
- inner and outer membrane
42
what is the role of thylakoid space
contains enzymes for photolysis
43
what is the role of the thylakoid membrane
- proteins (chlorophyll/photosystems, ATP synthase, electron carriers)
- involved in light dependent reactions
- system of interconnected fluid filled sacs
44
what is the role of the stroma
contains all enzymes for light independent reactions
45
what is a granum
a stack of thylakoids
plural = grana
46
what is a starch grain
stores the product of photosynthesis
47
describe the inner and outer membrane
- permeable to CO2 and H2O
- contains proteins that regulate the passage of substance across the membranes
48
describe the DNA loop
contains genes for some proteins
49
what are the two mainstages of photosynthesis
- light dependent
- light independent
50
describe the steps of the light dependent reactions
- light absorbed by chloroplast PSII in thylakoid membrane ans **2** electrons are excited to high energy levels
- electrons leave PSII and are picked up by the first electron carrier molecule in electron transport chain ETC, electrons replaced by photolysis- hydrogen and oxygen are by-product
- electrons move through ETC in a series of **redox reactions**
- during redox ENERGY IS LOST and used in **photophosphorylation** used to synthesis ATP
- light excties 2 electrons in PSI and they leave to the 2nd ETC, electrons replaced by PSII electrons
- electron from PSI ETC combines with H+ and NADP to reduce ot to NADPH
51
what is the movement of H+ known as
chemiosmosis
52
describe ATP
- adenosine triphosphate
- energy transport molecule
- contains adenine, ribose and 3 phosphate groups
53
describe ADP and Pi
- adenosine diphosphate
has been **dephosphorylated** in a hydrolysis reaction
- the lost phosphate group (Pi) get hydrated
releases energy
CATALYSED BY ATPase
54
describe phosphorylation
- ATP produced by condensation reaction
ADP + Pi ----> ATP
requires energy and ATP synthase
55
is the ADP + Pi ----> ATP reaction reversible?
yes
56
what is NADP
a co-enzyme
- hydrogen carrier
57
where does the light dependent reactions take place
- thylakoid membranes
- only in day time/light
58
where does the light independent reactions take place
- stroma
- happens in light and dark
59
what is the Calvin cycle
- a metabolic pathway where each stage is catalysed by enzymes
- the light independent reactions in photosynthesis
60
what is carbon fixation
the carbon from inorganic molecules is fixed in organic molecules, making it available to other organisms
61
describe the process of carbon fixation
6CO2 combines with 6RuBP (ribulose biphosphate) to create an unstable 6C compound that immediately breaks down to 12 GP (glycerate 3-phosphate)
- catalysed by RuBISCO - globular protein (ribulose biphosphate carboxylase)
62
describe the formation of GALP
12 GP receive energy from dephosphorylation of ATP and receive a hydrogen atom from the oxidation of NADPH
- GP is reduced
12 GALP is made (glyceraldehyde 3-phosphate)
63
what happens after the 12 GALP are produced
- 2 GALP is removed
- the remaining 10 GALP are phosphorylated by the hydrolysis of ATP to produce 6RuBP
64
what can the 2 GALP removed be used for
- nucleic acids
- amino acids- proteins
- alpha glucose - starch - **respiration**
- beta glucose- cellulose
- glycerol- triglycerides and phospholipids
KNOWN AS ORGANIC MATTER OR NPP
65
Why does photosynthesis take place in chloroplasts?
- maintain optimum local environment separate from the rest of the cell
Thylakoids keep electrons carriers in close and correct order, increases efficiency of reaction
Compartmentalisation increases no. Of collisions and therefore increases reaction rate
66
What is a food chain
Feeding relationships where energy is transferred from producer to consumer
67
What is a trophic level
A position a species occupies in a food chain
68
What is a food web
Where each organism eats or is eaten by several other organisms
69
What are detritivores
Primary consumers that feed on dead material called detritus
70
What are decomposers
Species of bacteria and fungi that feed on dead remains of organisms and animal faeces
- secrete enzymes to digest food externally
71
What are the limiting factors of photosynthesis
- temperature
- light intensity
- light wavelength
- CO2 concentration
- water availability
72
How do you calculate percentage efficiency of photosynthesis
% efficiency = GPP/ amount of energy arriving at plant surface. X 100
73
How are NPP and GPP linked
GPP = NPP +R
R is respiration
74
Define productivity
The rate of the incorporation of energy into organic molecules/biomass is an ecosystem
75
Define GPP
Gross primary productivity
- rate a high energy is incorporated into biomass from plants
76
Define NPP
- net primary productivity
Rate at which energy is transferred into biomass that makes up new plant biomass
- the energy after respiration
77
Define biomass
The mass of living material present in a given area
78
Why dens 100% of available light get turned into biomass
- light reflects off leaf
- energy used to evaporate water
- chlorophyll only absorbs 40% of light - specific wavelengths
- light may travel straight through the leaf without hitting chlorophyll
- light may be in excess of
79
How is energy lost between producers and primary consumers
- Not all available food gets eaten
- some food will remain undigested
- respiration
80
Why is energy transfer more efficient between primary and secondary
- most of a herbivore may be eaten
- high protein diet is more easily digested
81
Define productivity
The rate of the incorporation/generation of energy into organic molecules/biomass in an ecosystem
82
What is GPP?
Gross primary productivity
- the arte at which energy is incorporated into biomass by plants
83
What is NPP
Net primary productivity
- GPP -R = NPP
- rate at which energy is transferred into biomass that make up new plant biomass
84
Define biomass
The mass of living material present in a given area/ecosystem
85
Why isn’t 100% of the light that falls on leaves incorporated into biomass?
- light is reflected off the leaf
- energy is used to evaporate water
- chlorophyll only absorbs specifics wavelengths
- light doesn’t hit chlorophyll and transmits straight through the leaf
- light may be in excess
86
What is the equation for % efficiency of photosynthesis
% efficiency = GPP/ amount of energy on plant surface X100
- Jm*-2*y*-1*
87
Why is Jm*-2*y*-1* used as a unit
- m*-2* allows comparison between habitats
- y*-1* cover all seasons and weathers
88
How is energy lost between producers and primary consumers
- not all food is eaten
- some food will remain undigested (cellulose)
- respiration
89
Define food chain
Feeding relationships where energy is transferred from producer> 1/2/3 consumer
90
Define trophic level
The position a species occupies in a food chain
91
Define food web
Where each organism eats or is eaten by several other organisms
92
Describe detritivores
Primary consumer that feed on dead material called detritus
93
Describe decomposers
Species of bacteria/ fungi that feed on the dead remains of organisms and animal faeces
- heterotrophs and secrete enzymes the digest food externally
94
What are the limiting factors of photosynthesis
- temperature
- CO2 conc.
- water availability
- light intensity
- light wavelength
95
Why is energy transfer more efficient between 1-2 consumers
- most of a herbivore can be eaten
- the rote in rich diet is easily digested so less is lost in faeces
96
What are the 3 main possible outcomes for energy entering a trophic level
- transferred to surroundings in respiration
- transferred to next trophic level
- transferred to decomposers
97
Why is pollen useful
- vast quantities are made and is available for analysis
- resistant to decay
- distinctive and unique allowing for plant identification
- forms in layers in peat so time frame is established
- gives info on past climates
98
Describe temperature records
- go back 200-300 years
- however equipment used to collect data may be inaccurate
99
Describe peat bogs
An accumulation of partially decayed organic matter
- go back 2-3 centuries
- have anaerobic and acidic conditions that prevent decomposition
-growth, enzyme activity
- waterlogged
100
Describe dendrochronology
Studying tree rings
- every year another is made as a new layer of xylem vessels is formed
- water availability and warmth will impact growth
- better growing conditions- larger xylem vessels- thicker rings
- can be used to date a tree and look at past climates
101
Describe ice cores
Used to indicate past climates as the air trapped in bubbles will give an indication of the atmosphere at that time
- oxygen isotopes, CO2 conc. and air temp.
102
What has happened to rainfall patterns
- intensity of rain has increased but not necessarily the number of days t rains
103
Describe what happens to solar radiation
- most UV will by absorbed by ozone in stratosphere
- some visible radiation is reflected by earth
- some is reflected by clouds
- most solar radiation is absorbed but the earth’s surface which warms up
104
Describe what happens the the infrared radiation emitted form the earth’s surface
- some will escape the earth’s atmosphere and will cool don the earth
- some will be absorbed by greenhouse gases warming the troposphere
105
What are the main gases in the atmosphere
- nitrogen , oxygen, argon
106
What are g=considered green house gases
- CO2
-CH4
- nitrous oxide
- CFCs
107
Describe the greenhouse effect
- greenhouse gases (CO2/CH4) accumulate in atmosphere
- absorba nd trap IR radiation from the earth’s surface
- results in an increase in mean temp. Of the earth’s surface and atmosphere
108
What 3 things should be considered about a green house gas
- abundance in atmosphere
- average lifetime (long lifespan)
- global warming potential / can absorb IR radiation
109
What processes release CO2
- combustion of fossil fuels
- respiration
- lower CO2 absorption vía deforestation
110
What processes release methane
- anaerobic decomposition of organic matter/domestic waste
- incomplete combustion
- digestive systems (of cattle)
111
Define a controversial issue
An issue where alternative viewpoints can be reasonably held
112
Why is climate change remain controversial
- science can’t prove theories, only disprove them
-data may support an idea but does not prove it
- the is I’m=complete knowledge of climate systems
113
What is the general consensus on climate change
Temperatures are rising and the climate is changing (may be partly due to increased CO20
- reached from the gradual build up of scientific evidence
114
What may others believe about climate change
- changes in temp. Are part of a natural climate cycle
- changes in sun’s activity
115
What may influence people’s conclusion
- personal values and viewpoint
- political + economic considerations
116
What are the ethical arguments surrounding climate change
- we all have the right to choose whether or not to use fossil fuels
- we have a duty to allow others to improve living standard
- we have a duty to preserve the environment for the next generation
