ecology

• structural adaptions are features of the body structure eg. shape or colour, such as camouflage, insulation, attracting a mate, defense
• behavioural adaptations are when behaviour changes throughout the year, such as migration or hibernation
• functional adaptations are processes inside an organism's body, such as conservation of water, reproduction, defense
• a population is a group of organisms of the same species living in an ecosystem
• a community is all living organisms, of all species, living in an ecosystem
• an ecosystem is all living organisms and non-living components in a specific area, and their interactions
• biotic factors are living factors that affect other organisms or shapes the ecosystem in one way, such as predation, amount of disease or amount of food
• abiotic factors are all non living parts of the environment that affect organisms, such as light intensity, temperature or carbon dioxide concentration
• interdependence is when organisms are dependent on each other for survival, eg food, shelter, pollination, seed dispersal. if one species is removed, it can affect the whole community. a stable community is where all species and environmental factors are in balance - population sizes remain constant over time.
• producers are organisms that make their own food, eg plants convert light energy into chemical energy and make glucose, lipids, sucrose and amino acids for their own benefit
• consumers are organisms that are unable to make their own food. they have to feed on other organisms to take in complex organic molecules and break them down into simpler molecules that can be absorbed by digestion.
• a food chain shows the feeding relationships between organisms, involving the transfer of energy and nutrients from one organism to another
• a food web is a more accurate representation of feeding relationships as most organisms eat more than one type of food.
• a top carnivore is a carnivore occupying the top level of a food chain, they aren't consumed by other animals
• a scavenger is an organism that consumes decaying biomass
• detritus feeders consume dead/decaying plants and animals and their excreta
• decomposers decompose organic material
• parasites are organisms that live in or on a host organism and gets food at the expense of its host
• a saprophyte is an organism that lives on dead or decaying organic matter.
• predator-prey relationships: a predator consumes and hunts other organisms, it is adapted to hunt and kill, eg sharp teeth, claws, strength, speed, venom/toxins. a prey is what predators kill for food, they are adapted to avoid capture, eg camouflage, good senses, defensive behaviours, speed
• deforestation is when forests/woodland are cut down for timber. land is cleared for crops for human food, to produce biofuels, and for grazing of animals. it can be prevented by managing forest resources, banning clearcutting, and replanting trees. the effects are infertile land, leaching of soluble nutrients in soil, soil washed away, an increase in carbon dioxide and a decrease in oxygen
• peat bogs are natural areas of land that are acidic and waterlogged, so when plants die they do not fully decay as the environment is anaerobic. lots of carbon dioxide is locked up inside peat. they are drained for farmland or peat is used as fuel or compost. however, this means carbon dioxide is released into the atmosphere when peat is burned.
• greenhouse gases in the atmosphere act as an insulating layer, this is essential to keep the temperature of the earth at a level to sustain life. high gas levels cause global warming. carbon dioxide is produced when fossil fuels and wood are burned. methane is released from cattle and rice fields. climate change leads to ice caps melting (rising sea levels), change in rainfall patterns (flooding), and a change in ecosystems (extinction and loss of biodiversity)
• pollution is the presence in the environment of substances in the wrong amount, place, or time.
• air pollution

  • soot - tiny particles of carbon and tar blacken buildings, damage leaves and stop light reaching the ground
  • particulates cause respiratory problems
  • sulfur dioxide and nitrogen dioxide cause acid rain
  • carbon monoxide is toxic and causes illness and death
  • CFCs are stable and unreactive so react with ozone to form chlorine monoxide
• water pollution

  • more fertilisers (containing nitrates and phosphates), sewage (from homes), toxic chemicals (from acid rain), heavy metals (from industry), and plastic in rivers, lakes, and oceans
  • the presence/absence of indicator species can indicate levels of pollution in an area, as different invertebrates can tolerate different levels of pollution
• eutrophication is the sudden increase in nutrient content of a lake or river;

  • organic material, eg fertilisers, pollute water, causing algae to grow rapidly (algae bloom)
  • algae block out light below as they absorb the light for photosynthesis
  • plants in the water die
  • bacteria decompose the organic matter and use up all oxygen for aerobic respiration
  • oxygen levels fall and aerobic organisms die
• the carbon cycle

  A) combustion

  B) respiration

  C) respiration in decomposers

  D) feeding

  E) photosynthesis

  F) respiration

  G) fossilisation

  
• the water cycle

  A) evaporation

  B) transpiration

  C) condensation

  D) precipitation

  E) ground water