Paper 2

• Decomposition

  Death of organisms and excretion

  Putrefying bacteria and fungi break down the material to ammonia
• Nitrification

  Ammonia is converted to nitrates

  Nitrifying bacteria carry out this process
• Denitrification

  Nitrates convert into nitrogen gas

  Denitrifying bacteria carry out this process
• Assimilation

  Nitrates are absorbed by active transport into plant root hair cells

  Plants use this to make amino acids to form proteins
• Nitrogen fixing

  Nitrogen in the air is converted into nitrates in soil

  Nitrogen fixing bacteria
• What do animals compete for?

  Food

  Territory

  A mate
• What do plants compete for?

  Water

  Minerals

  Sunlight
• Ecosystem

  All the living organisms and physical conditions present in an area
• Deposition

  The change from water vapour to solid water through the liquid phase
• Biomass

  The mass of all living material
• Transpiration

  The release of water vapour from plants and soil into the air
• Evapotranspiration

  The sum of evaporation and plant transpiration from the earths land surface to atmosphere
• Advection

  The movements of water in any state through the atmosphere
• Percolation

  Where water flows horizontally through the soil and rocks under the influence of gravity
• Sublimation

  The change from solid water to water vapour without passing through the liquid phase
• Infiltration

  The flow of water from the ground surface into the ground
• Run off

  The variety of ways in which water moves across the land
• Biotic factors

  The living components of an ecosystem interacting with one another
• Abiotic factors

  Non living chemicals and physical factors that influence the living components of an ecosystem
• Examples of abiotic factors:

  Physiographic

  Soil (edaphic)

  Climatic
• What are physiographic factors?

  Aspect (direction faced in relation to the sun)

  Slope

  Altitude
• What are soil (edaphic) factors?

  pH

  Texture

  Air content

  Water retention
• What are climatic factors?

  Light

  Temperature

  Water

  Atmospheric

  Gasses

  Wind
• What does the producer do?

  Photosynthesise to create glucose using energy from the sun
• What does the consumer do?

  Eats other organisms to gain energy
• What does the predator do?

  Hunts or kills another organism for food
• What is consumption?

  Animals eat plants and digest the plant proteins to make their own proteins
• What is a habitat?

  A place where an organism lives
• What is a community?

  All the different populations living in the same habitat at the same time
• What is population?

  The number of organisms of the same species living in an area
• What are species?

  Organisms that can reproduce to create fertile offspring
• Interspecific

  Different species
• Intraspecific

  Same species
• Interdependence

  Where all organisms within a food web or ecosystem are dependent on one another for survival
• Mutualism

  Both organisms benefit
• Parasitism

  The parasite benefits but the host organism is harmed
• Heterozygote

  An organism that has two different alleles for a gene
• Homozygote

  An organism that has two of the same alleles for a gene
• Genotype

  The combination of alleles an organism has
• Phenotype

  The observable characteristics an organism has