Topic 5 Wood Flashcards
Abiotic
non-living or physical
Anthropogenic
factors that arise from human activity can be biotic or abiotic
Bioshere
part of the Earth that is inhabited by living organisms
Biotic
living factors
Community
the different populations that share an ecosystem or habitat
Ecosystem
consists of all living organisms in a given area including the abiotic factors (is DYNAMIC)
Edaphic
ground/soil related conditions e.g. pH, salinity
Habitat
particular place where an organism is found
Interspecific
competition between different species
Intraspecific
competition within the same species
Niche
the role of an organism within its environment e.g. where it lives, what eats, mates (two organisms can’t share the same niche)
Population
a group of individuals belonging to one species
Topography
height and gradient of the land e.g. altitude, slope, aspect. climate, drainage
Examples of abiotic factors
- solar energy input
- climate
- topography
- oxygen availability
- edaphic factors
- pollution
- catastrophes
Examples of biotic factors
- competition (both inter and intra specific)
- grazing
- predation
- parasitism –> one depends on the other and only one gains something from it
- mutualism –> both depend on each other and gain something from the relationship
Examples of anthropogenic factors
- climate –>pollution
- topography –> buildings
- oxygen availability –> deforestation
- competition –> destroying habitats, zoos
- grazing –> control where they graze
Adaptations
species survive due to adaptations that enable them to cope with conditions in their niche
Carrying capacity
a central value that the environment can hold (more than central, too much competition)
Adaptations come about by
random spontaneous genetic mutations
What methods give evidence for climate change?
- temperature
- ice cores
- dendrochronology
- pollen
How do ice cores show climate change:
- as water freezes, bubbles of air are trapped in the ice, this traps oxygen and carbon dioxide
- the ratio of different oxygen isotopes present gives an estimate of average temperature when the ice was formed
- carbon dioxide concentration of bubbles can be measured
- ice core data is similar to directly measured data which suggests accuracy of technique and therefore ice core data
What is peat?
an accumulation of partially decayed organic matter, mainly remains of dead plants
What is within a peat bog?
decayed organic matter
How do peat bogs slow/ stop decay rate?
the anaerobic and acidic conditions slow decay rate/ stop decay completely because no microbes or other organisms that allow decay to occur are within it
How does pollen show climate change?
- pollen falls to the ground
- pollen is resistant to decay
- each species of plant has distinct pollen
- peat forms in layers –> older peat (carbon dated)
- each species of plant has ecological conditions where it flourishes
- pollen found in different layers of peat bogs can be used to indicate the conditions at that time
Overview of evolution
- variation within population
- random spontaneous mutations
- changing selection pressures
- advantageous/ not –> survive, breed, pass on/extinction
- changing allele frequencies due to inheritance
Speciation observations
- offspring resemble parents
- all individuals display variation
- all organisms have potential to produce large numbers of offspring
- populations remain fairly constant
Speciation conclusions
- most offspring don’t survive to breed
- only best adapted individuals survive to pass on characteristics
- over time and with the correct circumstances a number of changes may give rise to new species
Species
closely related individuals that can interbred successfully to produce fertile offspring
Speciation
the formation of a new species from an existing one - there must be an isolating medium for it to occur
Allopatric speciation
- relies on physical barriers like mountains or islands to separate populations
- new species arise due to genetic drift and local adaptation
Sympatric speciation
- organisms within the same habitat
- new species arise due to different aspects within the habitat (food, mates, biochemical)
- often species that won’t mate with in other in the wild will do so under lab conditions
Ecological Isolation
species occupy different parts of the same habitat
Temporal isolation
exist in the same area but reproduce at different times
Behavioural isolation
exist in the same area but don’t respond to each others courtship behaviour
Physical incompatibility
co-exist, but there are physical reasons that prevent them from having sex
Hybrid inviability
produce hybrids, however they don’t survive long enough to breed
Hybrid sterility
produce hybrids which survive to reproductive age but cannot reproduce
Geographical isolation
separated by physical barriers
Why are carbon dioxide levels increasing?
because the carbon cycle isn’t in balance –> this is due to combustion of fossil fuels and deforestation
CO2 - combustion of fossil fuels
when fossil fuels are burnt, the carbon released is that that hasn’t been circulating in the atmosphere for millions of years, we’re burning them faster than they’re forming
CO2 - deforestation
if an ecosystem is stable then photosynthesis = respiration, if cut down photosynthesis drops and eventually respiration drops and initial CO2 released > absorbed
How can we maintain carbon balance?
- use sustainable resources e.g. biofuels which are carbon neutral
- reforestation –> would absorb some CO2 but there would be a limit to this and the ocean acts as carbon sinks
- renewable energy sources
Why increase quadrat size?
- make it more precise
- easier to work out distribution of organisms
Valid results
- repeats
- control variables
- actually testing statement
- no data on other factors
How does the presence of organelles such as chloroplasts lead to greater efficiency in biochemical pathways within cells?
the organelles are specialised in function which leads to a greater efficiency as everything for a particular process is in one area of the cell - doesn’t need to be transported around
