Ecosystems

• A habitat is the place where an organism lives. The environment is the conditions which exist in a habitat
• An ecosystem is a particular habitat within a community where they interact together
• woodland consists of areas with fewer trees and more scattered trees then forests 


  A maquis is a shrubby, mostly evergreen vegetation found in Mediterranean coastal regions. There are very few or no trees, but mostly shrubs are found here
• A Garigue is low open shrubland with many evergreen shrubs, low trees, aromatic herbs and bunchgrasses found in poor or dry soil in the Mediterranean region. land is more deprived of fauna then maquis 


  Freshwater has a low salt concentration usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration (for example the ocean). There are different types of freshwater regions : ponds and lakes
• Sand dunes are hills of sand, typically found in deserts and other arid regions. The formation of sand dunes is affected by wind

  Rocky shores are an intertidal area (where waves break in rock pools) of seacoasts where solid rock predominates
• An organism's environment is made up of two parts. One of which is the physical (abiotic) environment for example light, temperature and water
• An organism's environment is made up of two parts. One of which is the biological (biotic) environment, for example, factors caused by all other organisms in the habitat, such as competition, predation and disease
• A nature reserves is Ghadira Nature Reserve
• An ecological niche of a species is the role that species has in the ecosystem. It is when a species interacts with other members of its community and the physical features of its suroundings
• In an ecosystem, there can be organisms which are native to that particular ecosystem and have evolved and are an integral part of the natural system
• alien species are species that were introduced to an ecosystem. These species cause disruptions in the ecosystem and result in the displacement of Indigenous organisms
• Endemic species are organisms which are native species and are also restricted to living in certain places
• symbiosis is the interaction between two different organisms living in close physical associations (animal interaction)
• Preditation is the most common relationship in nature that helps to keep both predator and prey in check
• An example of a prey in Malta is the Egyptian vulture
• For an organism not to be eaten, it hides. One of the ways that it hides is by mimicry which is characterised by the superficial resemblance of two or more organisms that are not closely related taxonomically
• For an organism not to be eaten, it hides. One of the ways that it hides is by camouflage which is a defence or tactic that organisms use to disguise their appearance, usually to blend in with their surroundings
• mutualism is an association where two partners are presumed to derive some benefit from the association (so both organisms benefit from each other) an example is good bacteria
• certain bacteria can absorb nitrogen and build it up into nitrates and proteins. They are called nitrogen-fixing bacteria and are found living in the roots of leguminous plants (peas and beans) where they cause swellings called root nodules. The plant benefits from extra nitrates that the bacteria provide where the bacteria are protected in the plant's cells and can also use the sugars made by the plants photosynthesis
• Nodules are the sacs that contain protein, carbon, hydrogen, nitrogen and sometimes sulfur. Nitrogen is needed for the pant to build protum
• Taenia (tapeworm)


  • Scolex with two rows of hooks and four suckers to hold on tightly to the intestine wall
  • Thick cuticle not digested by host's digestive juices due to substance produced
  • Flat shape for large surface area to absorb host's digested food
  • Anaerobic respiration due to little oxygen in intestine
  • Hermaphrodite to produce both male and female gametes essential as only one worm can be accommodated at a time
• Taenia (tapeworm)


  • 2-8m long
• The adaptations of the Taenia (tapeworm) to a parasitic mode of life
• Response of plants to abiotic factors: tropisms

  A shot will grow towards a light source but away from gravity. A root will go towards gravity but away from light

  Responses to light are called phototropisms and responses to gravity are caled geotropisms
• A shoot is made to grow by a hormone called auxin produced in the tip. The auxin passes down the shoot causing the cells behind the tip to expand

  Auxin moves away from the sun
• Water is another aerobic factor that affects the roots of a plant as the roots of the plant will move to where there is water available. This is called hydrotropism
• The pyramid of numbers shows the number of organisms there are and it is usually inverted because there could be many organisms feeding off of one tree/plant
• The pyramid of biomass is an upright pyramid showing the amount of organisms
• Decay is the breakdown of the bodies of dead organisms. Decomposers bring it about. Decomposers are microorganisms (mainly bacteria and fungi). The conditions needed for decay are

  Moisture

  warmth
• food chains that are important to humans are

  Grass-->cattle--> human

  Plant plankton-->animal plankton--> animal plankton--> fish--> human
• Although the earth can be considered as a closed system, there is still an exchange of energy and of some matter