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
