Topic 5 Flashcards
How does carbon dioxide act as a greenhouse gas?
Absorbs infrared radiation reflect off the surface of the earth
Explain how studying pollen grains in peat bogs can provide evidence of climate change?
Pollen is preserved in peat bogs
Plant species can be identified from its pollen
Climate change will affect how different species grow
Depth of the peat correlates to how long since the pollen was produced
Changes in pollen overtime indicate changes in climate change
What are some methods that can provide evidence for climate change?
Dendrochronology
Peat bog pollen analysis
Ice cores
Discuss the possible impact of climate change on the effects of leaf rust on the yield of wheat crops.
Climate change can result in increased temperature / humidity / change in rainfall patterns / drought
Increase in temp would cause more growth of leaf rust
Increased rainfall / humidity would increase the spread of the leaf rust
Period of drought could reduce the leaf rust
Therefore this would impact crops
Explain why anthropogenic emissions of greenhouse gases are affecting the climate.
Human activity example (burning fossil fuels / landfill / deforestation / cattle farming)
This will increase greenhouse gas (carbon dioxide / methane)
Therefore more heat energy / infrared radiation is trapped in the atmosphere
This causes a mean increase in the surface atmospheric temperature
State what is meant by the term Q10 temperature coefficient
The ratio of the rate of an enzyme reaction taking place at temperatures differing by 10
State what is meant by the term ecosystem
Organisms and (non living components / abiotic factors)
How would you describe the role of photosynthesis in the carbon cycle?
Carbon dioxide is reduced to form organic molecules
Explain why the value for GPP is lower than the light energy available to the ecosystem
Not all light falls on leaves / plants / producers
Some of the light is reflected from the surface of the leaf
Some of the light misses the chloroplasts and passes straight through the leaves
Some of the light is not absorbed by chlorophyll (wrong wavelength)
Explain why respiration affects the production of biomass
GPP - R = NPP
Organic molecules / glucose used in respiration provide energy
The more organic molecules / glucose used in respiration, the less available for the production of biomass
Explain why burning wood chips does not increase carbon dioxide to the atmosphere in the long term.
CO2 produced by burning wood replaces that absorbed by trees
Trees absorb CO2 from the atmosphere for photosynthesis
New trees are grown to replace those that are cut down
Therefore no net increase in CO2
Explain how two species of African elephant could evolve from a common ancestor.
Two populations because geographically isolated from each other
Therefore reduced gene flow between the two populations
This leads to allopatric speciation
Different selection pressures will lead to natural selection
Tropical rainforests play a role in maintaining biodiversity and in storing carbon. Explain how reforestation of tropical rainforests can be used to minimise climate change
New / young / growing trees
Resulting in a net uptake of CO2 / more CO2 taken in by photosynthesis than released by respiration
Therefore reducing CO2 in the atmosphere
This slows the rate of global warming
Describe how the Hardy-Weinberg equation can be used to provide evidence for changes in the elephant population in Mozambique.
Can calculate the allele frequencies / number of dominant and recessive alleles in the population
Regular sampling over a period of time
Describe how forests can be managed as a sustainable resource
Replacing trees that have been cut down
Removing / cutting down older trees
Replace with seedlings / rapidly growing trees
Explain the impact of cutting down trees on climate change.
There will be less photosynthesis
Less CO2 will be fixed / more CO2 in the atmosphere
CO2 is a greenhouse gas so more heat energy trapped in the atmosphere
Increase in atmospheric temperature / increase in climate change
Name the plant organelle that fixes carbon dioxide from the atmosphere.
Chloroplast
Describe how starch is formed from the products of the light-independent reactions of photosynthesis.
Two GALP used to produce a glucose molecule
Glucose molecules are joined by glycosidic bonds to form starch
Condensation reactions
Producing amylose and amylopectin
Describe the light-dependent reactions of photosynthesis.
Light energy excites electrons in chlorophyll / increases electrons energy level
Photolysis to produce oxygen, hydrogen ions and electrons
Electrons used in ETC to replace those lost in chlorophyll / PSII
Photophosphorylation / generation of ATP
Reduction of NADP
Explain why this increase in carbon dioxide concentration affects the growth of plants in glasshouses.
CO2 is a limiting factor
CO2 is fixed to produce GP/ GALP
Increased CO2 results in more polysaccharides / glucose / carbohydrate being produced
Which leads to greater rate of cell division
Where, in the chloroplast, do the light-dependent reactions take place?
Thylakoids
What are the products of the light-dependent reactions?
Reduced NADP, ATP and Oxygen
State the location of chlorophyll in a chloroplast.
Thylakoid membrane / granum
What is the name of the enzyme used by plants to fix carbon dioxide?
RUBISCO
What is the immediate product of the light-independent reactions of photosynthesis?
Which of the following is the immediate product of the light-independent reactions of photosynthesis?
GP
State the location of the Calvin cycle.
Stroma of the chloroplast
Describe the roles of the products of the light-independent reactions in the Calvin cycle
Products are ATP and NADP
ATP is used to convert GP to GALP / GALP to RuBP
Reduced NADP used to convert to GP to GALP
Explain the importance of RUBISCO to the productivity of an ecosystem.
Fixes (inorganic) carbon
Allowing formation of organic molecules by the calvin cycle
These organic molecules allow transfer of energy to the next trophic level
Explain the relationship between the structure and functions of a granum in photosynthesis.
Granum is formed from many layers of thylakoid membrane to increase surface area (for absorbing light)
Thylakoid membrane contains chlorophyll to absorb light
Electron carrier molecules in thylakoid membrane involved in ATP production
Give two biotic factors, other than cutting down trees, that could affect the number of bird species observed in a forest.
Food availability / interspecific competition / predation / disease
Describe the difference between the terms niche and habitat.
Niche is the way an organism interacts with its environment
Habitat is the pace where an organism lives / community of organisms lives (has a distinct set of conditions)
Compare photosythsies,aerobic respiration and anaerobic respiration
Photosythsies - occurs in all photosynthetic organism, stores energy,converts light enegy into chemical energy , anabolic (builds molecules), ATP produced by photophoshorylation,occurs in chloroplast , requires light, requires a supply of co2, NADP Used, end products oxygen and glucose
Aerobic respiration- occurs in all living organisms, releases energy, converts chemical energy into chemical, catabolic reaction (breaks molecules) , ATP produced by substrate level phosphorylation and oxidative phosphorylation, occurs in mitochondria, does not require light, requires supply of oxygen, NAD used,end products co2 and water
Anaerobic respiration - lactate fermentation muscles and ethanol fermentation plants/fungi, releases energy, converts chemical energy into more accessible chemical energy , catabolic reaction (breaks down), ATP produced by substrate level phosphorylation, occurs in cytoplasm , does not require light, occurs in absence of oxygen, NAD used, end products lactate or ethanol
