5

Question 1

biotic and abiotic

Answer 1

a-physical and chem factors like soi and climate
b- factors detrmined by organisms- predation and comeptition

Question 2

ecosystem

Answer 2

all the organisms living in a parcular area, known as the community, as well as all the nonliving elements of that parcular environment (e.g. climate, nutrients being cycled etc.)- abiotic and biotic features

Question 3

community

Answer 3

all of the populaons of all the organisms living in a parcular habitat at a parcular time

Question 4

habitat

Answer 4

place where an organism Iives

Question 5

population

Answer 5

group of interbreeding individuals of the same species found in an area

Question 6

how abiotic and biotic factors control species abundance

Answer 6

Each species has a parcular role in its habitat, called its ecological niche. This consists of its biotic and abiotic interactions within the environment. Species distribuon and abundance within a habitat will depend on the number and type of ecological niches available within that habitat.
The niche concept states that only one organism can occupy each niche in a given habitat at a given me - if two or more species have a niche that overlaps, the best adapted will out-compete the others in surviving to reproduce.
interactions between abiotic and bitotic- poor weather reducing survival of a species affecting predators

Question 7

abiotic

Answer 7

solar energy inputcllimatetopography– altitude, slope, aspect, drainageo2 concedaphic factors- soil pH and mineral ion conc- underlying geology of the area pollution catastrophes

Question 8

biotic

Answer 8

competitiongrazing, predation, disease and parasitismmutiaismdensity depndent

Question 9

anthropogenic factors

Answer 9

arirising from human activity

Question 10

succession

Answer 10

the change in species inhabiting an area over time. It is brought about by changes to the environment made by the organisms colonising it themselves.

Question 11

primary succession

Answer 11

starts in a newly formed habitat where there has never been a community before

Question 12

stages of succession

Answer 12

pioner phase: colinisationpioner species-llinchen or algae- organisms able to survive inhospitable conditions at bare ground stagepioneers break up rock surface allowing some organic material to accumulate, create a shallow soil change conditions in the habitat just enough to make them suitable for other speciessmaller more complex plants able to grow in shallow soilsecondary communitysecondary community:pioneer species are replaced & complexity of species increases-As organisms die, they are decomposed by microorganisms, thus adding humus (the organic component of soil). This leads to the formaon of soil, which makes the environment more suitable for more complex organisms. As more organisms are decomposed over me, the soil becomes richer in minerals, thus enabling larger, more varied and more producve plantsEventually, a climax community is established - this is the most producve, self-sustaining and stable community of organisms that the environment can support, usually with only one or two species

Question 13

secondary succession

Answer 13

on bare soil where an existing community has been cleared- cleared from deforestation/ natural disasters- soil not completely bare- seeds dormnat in soil/ mineral present in soil

Question 14

defelcted succession

Answer 14

communty does not develop and succession is not completed due to human activity- grazing

Question 15

primary productivity of an ecosystem

Answer 15

the rate at which energy in incorporated into organic molecules in an ecosystem

Question 16

produces/autotrophs

Answer 16

organisms that can make their own orgain compounds from inorganic compounds

Question 17

chemisynthetic autotrophs

Answer 17

make organic molecules using energy released from chem reactions

Question 18

Net primary productivity (NPP)

Answer 18

the rate at which energy from the sun is converted into the organic molecules that make up new plant biomass.

Question 19

Gross primary producvity (GPP)

Answer 19

the energy transferred to primary consumers

Question 20

energy formula

Answer 20

R=energy used in respirtaion
NPP=GPP-R

Question 21

why energy is ost at each trophic level

Answer 21

• Undigested maer
• Respiraon (exothermic, transfers thermal energy to the surroundings)
• Metabolic waste products like urea

Question 22

photosynthesis equation

Answer 22

6CO2 + 6H2O -> C6H12O6 + 6O2

Question 23

chloroplasts

Answer 23

contain stacks of thylakoids called grana- thylakoids (flattened fluid filled sacs) contain the photosynthec pigments, such as chlorophyll, arranged as photosystems and electrin carriers. This is the site of the light-dependent stage of photosynthesisDNA loop- genes for some of their proteinsthyakoid space-fluid within the thylakoids membrane sacs which contains enzymes for photolysisouter membrane which is freey permabolle to molecules Ike co2 and H20 inner membrane contains many transport molecules- membrane proteins which regulate the passage of subastances in and out of the chloroplat- sugars and proteins synthesized in the cytoplasm of the cell but used in the chloroplast starch grain store products of photosyntheisstroma- fluid surrounding the thylakoids membrane- contains all enzymes needing to carry out ight indpendent reaction

Question 24

light dependent reaction

Answer 24

energy from light raises two electrons in each chlorophyll moleculreto a higher energy level- excites electronselectrons leave excited chlorophyll molecues and pass along a series of electron carrier molecules emmbeed in the thylakoids membrane- electron transport chainelectrons from photosytem II chlorophyll pass from one carrier to the next in a series of oxidation and reductio reactions- losing energy in process-energy from electrons pumps H+ from stroma- into thylakoid interior- greater H+ in interior creates a proton gradient- enhanced by protons being used in reduction of of NADP and photolysis- proton gradient used to generated ATP- ATP synthase has an ion channel where protons diffuse down into stroma- this causes photophosphoryation to occur - where ATP is formed from ADP +PIelectrons from PSII replace those lost in PSIelectrons lost from PSII chlorophyll need to be replacedin thyakoid space catalysing photolysis to give o2 gas ,H+ and e- these ectrons replaced those lost in PsII chlorophyll- raises hydrogen ion conc- in thyakoid space- 2H+ + 2e- + ½O2electrosn from PSI have passed along electron transport chain and combine with co enzymes NADP and hydrogen ions from water to form reduced NADP

Question 25

light independent reaction

Answer 25

takes place in stroma and uses reduced NADP and ATP- NADp acts as a hydrogen carrier carbon fixation- carbon dioxide combines with 5-carbon compound RuBP- catalysed by RuBISCO6-carbon compound formed in unstable and immediately breaks into 2 3 carbon compounds - GPGP is reduced to form a 3 carbon sugar GALP-hydrogen for reduction comes from the reduced NADP- ATP provides the energy required for endothermic reaction2/12 GALPs formed are involved in creating a 6 carbon sugar which can be converted to other compounds sych as amino acids or lipids10/12 GALPs are involved in the recreation of RuBP- 10 GALp rearrange to form 6 5 carbon compounds which are then phosphorylated using ATP to form RuBP

Question 26

% efficiency

Answer 26

(GPP/ around of light reaching pant)x100

Question 27

relationship between structure and function of geranium in thylakoid membrane

Answer 27

made of many layers of thylakoid membranes to increase surface area for absorbing light contain chlorophyll for absorbing light electron carrier proteins in thylakoid membrane involved in production of ATP and NADP

Question 28

why GPP is low than light energy available

Answer 28

not all the light falls on the leaves some light reflected from the surface of the leaves some of the light misses the chloroplasts and goes right through the leaf some of light is wrong wavelength and not absorbed bu the chlorophyll

Question 29

how respiration affects the production of biomass

Answer 29

NPP=GPP-R glucose used in respiration to provide energy because the more glucose/organic molecules used in respiration, the less is available for the production of biomass

Question 30

sampling method

Answer 30

soil- take temperature, humidity readings, elevation, soil type, water content, humus content use quadrats random sampling within area- random co-ordinates

Question 31

affects of pioneer species

Answer 31

bare rock colonised by pioneer species these pioneer species break up the rock dead plants add humus as they decompose eventually allows growth of more complex organisms as soil deeper, can retain more water had contains more organic materials

Question 32

role of thylakoid membrane

Answer 32

1. idea of compartmentalisation (from stroma) 2. site of light-dependent reaction 3. contian chlorophyll + electron carrier proteins 4.{ATPase synhase } in (thylakoid) membranes ; 5. idea that (thylakoid) membranes provide a space for accumulation of H+ ; 6. reference to photophosphorylation ;

Question 33

succesion

Answer 33

idea of a series of changes (that occur to the composition of species in the community) of organisms ( present in an area) over a period of time ;

Question 34

why environment climax

Answer 34

2. includes (both) animals and plants / has many species / has high biodiversity / eq ; 3. reference to {interaction / eq} between species / eq ; 4. idea of balanced equilibrium of species ; 5. reference to {dominant / codominant} (plant or animal) species ; 6. reference to stable if no {change to environment / human influence} ;

Question 35

temperature records

Answer 35

long data sets showing fluctuations of atmospheric a ocean temp over timemethodical thermometer based records started in 1850gives reliable but short term measure record of global temp changegeneral trend of temp is increasing

Question 36

peat bogs

Answer 36

pollen preserved in peat bogs- resistant to decaya plant species cane be identified from its pollen- each having a distinct type each plant has a particular set of ecological conditions climate affects the type of plant growing- increased colonization of plants suited to warmer climates over time depicts an increase in temperature throughout the yearsdepth of peat correlates with period of time since pollen was produced- seen through carbon dating changes in pollen overtime shows a change in climate

Question 37

dendrochronology

Answer 37

every year trees produce a new layer of xylem vessels by the division of cells underneath the barkdiameter of xylem vessel varies according to the seasonwide vessels in spring when the tree grows quicklynarrow vessels in summerlittle if any growth takes place during autumn and winterage of tree can also be found by counting rings or comparing thickness of rings to dated samples↳ diameter of rings will be the same for diff. trees in same area/ time due to similar climate

Question 38

co2 increase effects on ocean

Answer 38

• carbon dioxide dissolves in the (sea) water (1) • this increases the acidity of the water (1) • increased global warming could increase the water temperature (1) • therefore change in {temperature / pH} will denature the enzymes (so less seagrass survives) (1)

Question 39

ice cores

Answer 39

cylinders of ice drilled out of ice sheet / glacier on freezing , water traps air bubbles containing sample of atmosphere ↳provide direct measure ot past concentration of gases in atmosphere -temp can also be deduced by chemical analysis ↳ ratio of isotopes of oxygen changes wl climate

Question 40

greenhouse gases

Answer 40

sun radiates energy absorbed by earth earth radiates infrared back some radiated form earth absorbed by gases in atmosphere- greenhouse gases methane produced from anaerobic decay of organic matter in waterlogged conditions- decomposition of animal waste- digestive system of animals _ incomplete combustion

Question 41

hill reaction

Answer 41

Remove stalks​ from leaf samples. Cut into small sections. Grind sample using a pestle and mortar and place into a ​chilled isolation solution​. Place several layers of muslin cloth into funnel and wet with isolation medium to filter sample into a beaker. Suspend the beaker in an ​ice water bath​ to keep sample chilled. Transfer to centrifuge tubes and ​centrifuge at high speed for 10 minutes​. This will ​separate chloroplasts​ into the ​pellet​. Remove ​supernatant​ and add pellet to fresh isolation medium. Store isolation solution on ice. Set the colorimeter to the ​red filter​. ​Zero​ using a cuvette containing ​chloroplast extract ​and ​distilled water. Place test tube in rack ​30cm​ from light source and add​ DCPIP​. Immediately take a sample and add to cuvette. Measure the ​absorbance​ of the sample using the colorimeter Take a sample and measure its absorbance​ every 2 minutes for 10 minutes​. 11.Repeat for different distances from lamp ​up to 100 cm.​ This will vary the ​lightintensity​.

Question 42

why plant proteins produce less greenhouse gases than meat

Answer 42

• because plants produce {organic compounds/biomass} from photosynthesis (1) • plants remove carbon dioxide (from the atmosphere)(1) • because animals produce (more) carbon dioxide by respiration (1) • because (some) animals produce methane (1)

Question 43

why deforestation leads to increased greenhouse gases

Answer 43

• (deforestation cuts down) trees which are carbon sinks (1) • {burning / decomposition} of these trees releases carbon dioxide into the atmosphere (1) • without trees there is {less/no} photosynthesis to remove carbon dioxide (from the atmosphere) (1)

Question 44

why conditions of peat bogs prevent decomposition

Answer 44

• conditions are anaerobic (1) • therefore less (aerobic) respiration by decomposers(1) • acidic conditions {inhibit /denature} enzymes (1) • therefore (enzymes) cannot {digest / break down} organic material (1) water logging reduced oxygen concentration

Question 45

quadrants random sampling

Answer 45

use of quadrats for sampling (1) • method of determining co-ordinates for random sampling (1)- random number table • record percentage cover of sphagnum (in each quadrat) (1) • several {quadrats/samples} measured and mean calculated (1) • sample at regular time intervals (1) • calculate the rate of change in sphagnum cover (1)

Question 46

hill reaction

Answer 46

• Plants grown in the same conditions e.g. temperature, humidity • Plants grown in either 5% light or 25% light or a range of light intensities • Take same masses of leaf • Add to equal volume of isolation medium • Homogenise (e.g. blend / grind in pestle and mortar) for same length of time • Filter suspensions of plant material (through muslin) or centrifuge to concentrate chloroplasts • Resuspend pellet of chloroplasts if centrifuged • Expose suspensions to 5% and 25% light intensity • Keep temperature controlled • Add DCPIP and record time for DCPIP to decolourise • Carry out repeats to calculate mean time to decolourise the DCPIP • If the difference is due to the light dependent reaction, shade tolerant plants would decolourise more quickly at lower light intensity

Question 47

hill reaction

Answer 47

Homogenise leaves pasteadd sucrose (prevents diffusion of water out cell) and buffer solution(resists changes in ph so enzymes aren't dentaured)filter through muslin cloth put into test tubecentrifugetest tuber made up of supernatant and pelletremove pellet,into another test tube- add sucrose and buffer and over ice-mix- stops enzyme activity add DCPIPtest tube with only supernatant and only buffermeasure time to decolucrise in different conditions +

Question 48

effects of climate changes impact on change in rainfall patterns and seasonal patterns

Answer 48

change in distribution of species- species move to more northern areas where there are cooler climates- lead to extinction of some species through increased interspecific competition change to development- sex of many reptiles is determined by temp therefore an increases in temp will have an effect on the sex ratio of certian species thus contributing to extinction

Question 49

temp and enzyme activity

Answer 49

initally as temp increases arte of reaction increases as rate of frormation of enzyme-substarte complexes increases as kinetic energy of molecules increases thus leading to more frequent collisions decreases above optimum temp as enzymes start to denature

Question 50

Q10

Answer 50

rate of reaction at temp T + 10 °C / rate of reaction at temperature T rate of reaction aprox x2 on each increase of 10 °C describes what happens to the rate of reaction when the temp increases by 10 °C- value of 2 means the rate of reaction x2 upon each 10 °C increase does not apply above optimum

Question 51

global warming's disruption to life cycles

Answer 51

spawning, hatching, growth rate - warming environmental tempertuares affecting enzymes - growing/hatching earlier

Question 52

how change in hatching time impacts food supply

Answer 52

many species synchronise the hatching of their eggs with periods of max food availability - photoperiod laying of predators vs temperature dpendent laying of prey has negative impacts on prey pop when temps increase

Question 53

struggle for existence graph

Question 54

different types of sympatric isolation

Answer 54

ecological- diff parts of habitat temporal- same area buy reproduce at diff times behavioural-do not respond to each others' courtship behaviour physical incompatibility- co-exist but restricted by physical incompatibility- size or shape of genitals

Question 55

Carbon cycle

Question 56

fossil fuels

Answer 56

carbon remains locked in the fossil fuels instead of being recycled through decay and decomposition- carbon sink burning releases co2 into atmosphere- not net 0 as carbon was removed millions of years ago

Question 57

forests

Answer 57

carbon dioxide intake from photosynthesis expected to be level to carbon released from respiration carbon sinks, burnt or decomosed releases carbon trapped in the trees back into atmosphere whilst reudcing the amount carbon dixoide removed from the atmopshere through photosynthesis

Question 58

biofuels

Answer 58

produced directly from plants or indirectly from animals- carbon neutral and renewable- burning woods relases carbon taken from atmsophere from photosynthesis - need to take into account co2 used for transport methane, ethanol more expensive than fossil fuels destrution of trees to rpoduce areas for biofuel- realsing mass co2- harms widelife

Question 59

reforestation

Answer 59

carbon stores- repsiration lower than photosynthesis

Question 60

describing Q10

Answer 60

the ratio of the rate of an enzyme reaction taking place at temperatures differing by 10 degrees

Question 61

why might a piece of data not be useful in depicting a trend

Answer 61

cannot assume a trend will continue not enough data collected data only from one location- small sample size fluxuations in data

Question 62

ecosystem

Answer 62

organisms and non living components (abiotic factors)

Question 63

wh can biofuels not be defined as carbon neutral

Answer 63

ma overall be a increase in carbon dixoide conc carbon neutral forests carbon sink so clearing land leads to a net increase of co2 in atmosphere less plants means less carbon dixoide used for photosynthesis burning trees + decomosition leads to release of carbon dioxide burining biofuels releases carbon dioxide

Question 64

pioneer species

Answer 64

organisms able to survive inhospitable conditions at bare ground

Question 65

trophic levels

Answer 65

position of an organism in a food chain- producers=proudce organic molecules, passed up each tropic level, only pass 2% of amiable energy, digestion- sweat respiration, sun rays not on plant , reflect, decreases in ergo going up trophic levels

Question 66

how changes in chlorophyll result in changes of wavelengths of light absorbed\

Answer 66

change in the {3D structure / tertiary structure / bonds formed} (1) changes shape of (chlorophyll) light absorbing region (1) changing the quantity of energy needed to {release / excite} an electron

Question 67

how a community is climax

Answer 67

includes (both) animals and plants / has many species / has high biodiversity / eq ; reference to {interaction / eq} between species / eq ;- intra+inter 4. idea of balanced equilibrium of species ; 5. reference to {dominant / codominant} (plant or animal) species ; 6. reference to stable if no {change to environment / human influence} ;

Question 68

successzion points to remeber

Answer 68

more complex more comeptiotn for resorucesmore plants provider more niches for aimals, providing more biodivdersityNPP may reduce if trees redcing light intesnity

Question 69

how data indicates climate change

Answer 69

1. idea of {extrapolating / eq} data ; 2. idea of use for {modelling / investigation ofcorrelations} ; 3. idea of providing evidence for global warming ; 4. idea of using this data along with data from other sources ;

Question 70

how data does not indicate climate change

Answer 70

Idea that there is not enough data ; idea that data has only been collected from one area ; 3. reference to {no way of confirming data / no proof / not reliable} ; 4. idea of { fluctuations too great / no real trend} ; 5. idea that means are a poor representation of raw data ; 6. reference to {scatter / spread / eq} (of raw data) is indicator of reliability ; 7. idea that method of estimated temperature from growth rings is questionable / eq ; 8. other environmental changes (affecting trees)not taken into account / eq

Question 71

when to use transect wioth quadrats

Answer 71

because there is environmental gradient (1)