On the Wild Side Flashcards
Describe abiotic factors.
Physical or chemical factors: Solar energy input Climate Topography (altitude, slope, aspect, drainage) Oxygen concentration Edaphic (soil pH and mineral content) Pollution Catastrophes.
Describe biotic factors.
Living factors: Competition Grazing Predation Disease Parasitism Mutualism.
These factors are density dependent.
Describe anthropogenic factors.
Human activity.
Describe succession.
Colonisation is led by a pioneer species.
The final species is the climax community.
Secondary succession: seeds have wide dispersal, rapid growth, short life cycle, abundant seed production.
Describe deflected succession.
Remains stable due to human activity preventing succession.
Define gross primary productivity.
The rate at which energy is incorporated into organic molecules.
Define autotrophs.
Organisms that can make their own organic compounds from inorganic compounds.
Define net primary productivity.
The rate at which energy is transferred into the organic molecules making up cell biomass.
What is the calculation for net primary productivity?
Net primary productivity = gross primary productivity minus respiration.
Describe light-dependent photosynthesis.
Occurs in the thylakoid membrane.
Light energy excites two electrons per chlorophyll to an excited energy state.
Electrons travel down the electron transport chain via a series of redox reactions.
Energy is lost to synthesis ATP in photophosphorylation. Electrons from PSII replace those from PSI. Photolysis occurs, producing oxygen gas, H+ ions and electrons. The electrons combine with NADP to form NADPH.
Describe light-independent photosynthesis.
6xRuBP (5C) and 6xCO2 are catalysed by RuBISCO to form 12xGP (3C). 12xNADPH are oxidised to produce 12xNADP and 12xATP are phosphorylated to produce 12xADP and 12xPi. 12xGALP (3C) are produced. 2xGALP are removed to form Glucose (6C). The remaining 10xGALP are used to phosphorylate 6xATP to 6xADP and produce 6xRuBP (5C).
Describe primary consumers.
Herbivores. Heterotrophs that eat plant material.
Describe secondary consumers.
Carnivores. Eat primary consumers.
Describe tertiary consumers.
Eat other consumers.
Describe detritivores.
Primary consumers that feed on dead organic materials (detritus).
Describe peat bogs.
Anaerobic and acidic.
Plants all have different types of pollen. Pollen grains have a tough outer layer that is decay resistant. Peat forms in layers. Each plant has specific conditions.
Describe dendrochronology.
Trees grow new layers of xylem vessels. New vessels grow in accordance to season. Wide vessels in spring, narrow vessels in summer.
Describe DNA hybridisation.
When DNA is heated, base pairs break. We can mix it to make a hybrid. Not all bases complementary base pairs. Hybrid DNA denatures at lower temperatures.
Define profile sequencing.
Compares sequence of bases in different species. Fewer differences are more common ancestors.
Describe molecular clocks.
Molecular change in DNA over time can be used. Evolutionary trees can be formed.
Describe profiling.
Restriction enzymes cut at specific sequences. Produces fragments that can be visualised in bands. If there are mutations, restriction enzymes will not cut DNA.
Define allopatric speciation.
Geographical isolation.
Define sympatric speciation.
Reproductive isolation.
Describe ecological speciation.
Live in different parts of the habitat.
Describe temporal speciation.
Reproduce at different times.
Describe behavioural speciation.
Do not respond to mating behaviour.
Describe physical incompatibility.
Physical issues with reproduction.
Describe hybrid inviability.
Do not survive long enough to reproduce.
Describe hybrid sterility.
Cannot reproduce.
Describe the carbon cycle.
Release: Combustion Deforestation Volcanic activity Sedimentation Increase in acid rain.
Remove:
Sustainable resources.
Reforestation.
