Topic 5 Ecology Flashcards
Define ecosystem
A community of organisms in conjunction with non living factors
Define Community
The various different populations found in an area
Define population
A group of individuals of a single organism
Define habitat
Area with distinct set of conditions where an organism lives
Give the definition of biotic and abiotic factors
Biotic: factors based on living things like plants and animal interactions
Abiotic: factors based on non living things like sunlight and rainfall
State when it would be appropriate to use a spearman’s rank correlation analysis. Give an example
When examining two sets of data to determine how correlated they are to one another, an example of this would be plant coverage and light intensity along a transect.
State how you would correctly write a conclusion for the spearmans rank correlation if the result was significant.
At 10 DF and 5% significance level, the critical value is 0.648, our value is X, X>0.648 therefore we reject the null hypothesis, so there is a significant correlation between the two figures.
State how you would select the correct critical value to compare to in spearmans rank correlation
Use the number of pairs in the data at the 5% significance level
Stare how you would correctly write a hypothesis for the spearmans rank correlation
Null Hyp = there is no significant correlation between the two sets of data
Alt Hyp = There is a significant correlation between the two sets of data.
Give the definition of primary succession
Primary succession is the progression of a habitat from rocks to a climax habitat as the biodiversity of the area increases
Give the definition of a pioneer species
A plant species that can withstand harsh conditions that grows with very little nutrients, usually the first species to grow on rocks. The species has to transfer seeds by wind. Has to be able to fix nitrogen
Explain how pioneer species change the abiotic conditions in an ecosystem
When they die they break down into nutrient rich soil which can allow new plants to grow in their wake
Give the definition of a climax community
A community that has finished succession with a vast array of niches, and that has a vast biodiverse community of plants and animals
Explain the stages of succession from colonisation to climax community
Pioneer species grow on bare rock such as lichen,
Pioneer species break down into soil which is then exploited by new plants to grow and supply roots to hold the soil in place
New plants break down and form more soil, as the layer of soil becomes larger and more nutrient dense, larger plants can survive off the soil
Climax community where all plants and animals have competition and there is a vast variety of niches, Very little change occurs in the species at this point.
Where do light dependant reactions occur in the chloroplast
Thylakoid membranes
Where do light independent reactions occur in the chloroplast
Stroma
Define phosphorylation
Adding phosphate to a molecule (e.g. ADP-ATP)
Define Photophosphorylation
Adding a phosphate group using light
Define photolysis
Splitting (lysis) of a molecule using light (photo)
Define Hydrolysis
splitting of a molecule using water
Define decarboxylation
The removal of a carbon dioxide from a molecule
Define Dehydrogenation
The removal of hydrogen from a molecule
Define redox reactions
Reactions that involve oxidation and reduction.
What three things can be described by ‘reduction’
Gain of electrons,
Gain of hydrogen,
Loss of oxygen
What three things can be described by oxidation
Loss of electrons
Loss of hydrogen
Gain of oxygen
Definition of a Co-Enzyme + an example of a co-enzyme
A molecule that aids an enzyme, transfers a chemical group (e.g. hydrogen) from one molecule to another, e.g. NADP in photosynthesis
Give the use of NADP in photosynthesis
Transfers hydrogen from one molecule to another, therefore it reduces a molecule if it gives a hydrogen away or oxidises it if it takes it away from a molecule.
Give the balanced symbol equation for photosynthesis
6CO2 + 6H2O —> C6H12O6 + 6O2
Give the definition of photosynthesis
A series of chemical reactions that occurs in producers where light energy is converted into chemical energy
Explain the meaning of the acronym OILRIG
Oxidation is Loss of electrons,
Reduction is Gain of electrons
Give the equation to form ATP, state the name of the reaction and the enzyme responsible
Light dependant reaction, ATP synthase,
ADP + Pi + H2O —> ATP + O2
Explain how ATP can be used as an energy source
Broken down by hydrolysis to form ADP + Pi, which in turn releases energy
Describe the structure of ATP
Adenine base bonded to a ribose sugar bonded to three phosphate groups
(adenosine triphosphate)
Compare and contrast the structure of ATP to a DNA nucleotide
Both contain a nitrate group and a phosphate group
DNA contains deoxyribose whereas ATP contains ribose
DNA contains adenine, cytosine, thymine and guanine whereas ATP contains adenosine
ATP contains three phosphate groups whereas DNA only contains one.
State the adaptations a chloroplast has for photosynthesis
Chlorophyll for absorbing high energy frequencies of light,
Starch grain to provide energy for respiration
Enzymes to catalyse photosynthesis reaction
Higher surface area to increase light absorption.
Explain photolysis
Light energy excites electrons in bonds and causes them to move away from molecule, breaking the molecule
State the term used to describe the production of ATP via the light dependent reaction. Explain why it is given this name
Photophosphorlation because it requires light energy to attach a phosphate group to it
State the term used to describe the process by which electrons move down the electron transport chain. Explain why the term is used
Redox, as one molecule gets reduced and another molecule gets oxidised
State the three products of the light dependent reaction
ATP, Reduced NADP, Oxygen
State the role of the three products of the light dependent stage
ATP: Provides energy
Reduced NADP: Provides Hydrogen for LIR
Oxygen: Respiration / waste product
State the precise site of the LIRs
Stroma
State the alternate name for the light independent reactions
Calvin cycle
Describe what happens in carbon fixation
6CO2 binds to 6RuBP to form 12 GP, catalysed by rubisco
Describe what happens in reduction
12ATP hydrolysed to 12ADP + 12P, NADPH oxidised to NADP and 12GP Reduced to 12GALP
Describe what happens in phosphorylation in the LIR
2GALP Used in plant processes, 10GALP phosphorylated by 6P released by the hydrolysis of 6ATP to form 6RuBP
Describe the process of the light independent stage
6RuBP are bonded to 6CO2, catalysed by rubisco enzyme to form 12GP. 12ATP is hydrolysed to make 12ADP + 12P and 12 Reduced NADP Oxidised to 12NADP. These two processes cause 12GP to be reduced to 12GALP, 2 of those GALP form glucose and other metabolic products, 10GALP will form the 6RuBP via the hydrolysis of 6 more ATPs to form 6ADP + 6P which is used to phosphorylate the 10GALP
Describe how the products of the Light independent stage can be used to form cellulose cell walls.
GALP Condensed to form B-Glucose which then react together via condensation reaction to form an alternating inversion polysaccharide chain
Explain why the light independent stage relies on the light dependent stage occurring
Because the light dependent stage produces ATP and Reduced NADP which are used in various stages in the light independent stage
List 3 greenhouse gasses
CO2, CH4, Nitrous oxides
Give a definition of the term anthropogenic
Caused by human influence
Explain how greenhouse gases lead to the greenhouse effect
UV light shines onto earths surface, increasing surface temp, Heat energy is reemitted as infrared radiation into the atmosphere. Some infrared radiation escapes, some is absorbed by greenhouse gasses and reemitted back onto the earths surface, increasing average surface temp by trapping the infrared radiation in the atmosphere.
Give a definition of global warming
Increase in average global surface temp due to greenhouse gas action.
List the evidence of climate change
Pollen in peat bogs,
Dendrochronology
Temperature and carbon dioxide records
Give the definition of a biofuel
A fuel made from organic materials that can be sustainably reproduced
Explain why biofuels are considered carbon neutral
Plants absorb CO2 from atmosphere for photosynthesis, use this CO2 to produce the oils that are used as fuel, so when the fuel is burned it rereleases the CO2 back into the atmosphere therefore no new CO2 is being released.
Give the advantages of using biofuel over using fossil fuels
Doesnt release stored carbon into the atmosphere therefore does not contribute to global warming
Doesnt rely on finite resources therefore is sustainable
Give the disadvantages of using biofuels over fossil fuels
Biofuel production and transport requires energy that is produced by the burning of fossil fuels, therefore it is not carbon neutral
Biofuel production also requires the growing of monocultures which causes a decrease in biodiversity in the area and removes habitats that ecosystems used to rely on to thrive.
Give the definition of allopatric speciation
Speciation due to geographic isolation
Give the definition of sympatric speciation
Speciation due to random mutation that causes reproductive isolation
Two populations of mice occupy the same habitat but are defined as two separate species. State what type of speciation occurred to form these two species, give a reason for your choice
Sympatric speciation as they are not geographically isolated but still speciated
Two populations of sloth live on either side of the Andes mountain range and are defined as two separate species. State what type of speciation occurred to form these two species, give a reason for your choice
Allopatric speciation as there is a geographic isolation between the two species (mountain)
