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Describing Biodiversity

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Describing Biodiversity

  1. 1. Describing Biodiversity Sarah Jones
  2. 2. Observation and Inference • Observations are things or events that you notice i.e. see, smell, hear, touch or taste. • An observation can allow you to make an inference. • You can infer something when you use your observations and your previous knowledge to explain something.
  3. 3. Classification in Science • Classifying things into groups make them easier to remember, describe and identify again in the future. • The science of classifying is called Taxonomy. • There are almost 2 million classified organisms but Scientists believe there could be as many as 10 million organisms on Earth.
  4. 4. The 5 Kingdoms Biologist today have classified and divided all living things into five groups they call Kingdoms. These kingdoms are based on how living things are the same, and how they are different. • Monera • Protists • Fungi • Plants • Animals
  5. 5. Divisions • Kingdom • Phylum • Class • Order • Family • Genus • Species
  6. 6. Dichotomous Keys • Dichotomous = ‘cutting in two’
  7. 7. Characteristics for classifying • Size – microscopic/macroscopic • Skeleton – internal/external • Body Temperature – endotherm/ecthotherm • Legs – jointed/not jointed • Reproduction – internal/external • Skin – moist/smooth/scaly • Body covering – fur/shell
  8. 8. Invertebrates (95%) External or no skeleton
  9. 9. Vertebrates (5%) Internal skeleton or backbone
  10. 10. Endoskeleton and Exoskeleton • 75% of all animals have an exoskeleton – skeleton on the outside of the body. • Enodskeleton is a skeleton on the inside of the body. • No skeleton
  11. 11. 7 Subgroups of Vertebrates • Mammals • Aves (Birds) • Reptiles • Amphibians • Fish (with a cartilaginous skeleton) • Fish (with a bony skeleton) • Jawless fish
  12. 12. Endothermic and Ectothermic Endothermic animals can maintain a constant body temperature and are called warm blooded. The body temperature of ectothermic animals changes depending on their surrounding environment.
  13. 13. Types of mammals Placental Mammals – Very well developed when they are born – Grow inside the body – Attached by a cord to the placenta – Feed on milk
  14. 14. Marsupials – give birth when their young are at a very early stage of development and the mother provides milk – Almost all marsupials have a pouch – Include – kangaroos, koalas, possums and wombats
  15. 15. Monotremes – Only found in Australia and some nearby islands – Only two are the platypus and the echidna – They lay leathery-shelled eggs and after hatching the feed on milk.
  16. 16. Classifying plants • Bryophytes – mosses and liverworts • Gymnosperms – conifers • Angiosperms – flowering plants • Pteridophytes – ferns
  17. 17. Environment The environment of an organism is its surroundings, both living and non-living.
  18. 18. Ecosystems An ecosystem is a part of the environment containing living organisms interacting with each other and the non-living parts of the environment.
  19. 19. Ecology Ecology is the study of relationships living organisms have with each other and their environment.
  20. 20. Biodiversity “Biological diversity – or biodiversity – is the term given to the variety of life on Earth. It is the variety within and between all species of plants, animals and micro-organisms and the ecosystems within which they live and interact.”
  21. 21. Biodiversity comprises all the millions of different species that live on our planet, as well as the genetic differences within species. It also refers to the multitude of different ecosystems in which species form unique communities, interacting with one another and the air, water and soil.
  22. 22. Genetic Diversity Genetic diversity refers to the variety of genes within a species. Each species is made up of individuals that have their own particular genetic composition. Within a species there may also be discrete populations with distinctive genes.
  23. 23. Species Diversity • Species diversity refers to the variety of species within a region. • Species diversity is not evenly distributed around the world or across continents. Thirty-four biodiversity hotspots have been identified globally.
  24. 24. These hotspots collectively comprise just 2.3% of the Earth’s land surface yet hold especially high numbers of species that occur nowhere else – half the world’s plant species and 42% of all terrestrial vertebrate species.
  25. 25. Ecosystem Diversity Ecosystem diversity refers to the variety of ecosystems in a given place. Within any broader landscape there is a mosaic of interconnected ecosystems.
  26. 26. Ecosystems
  27. 27. Aquatic Ecosystems
  28. 28. Saltwater - open seas, estuaries and saltwater lakes. Approximately 65% of the Earth's surface is covered by oceans. Tides, currents, waves and wind continuously move the water in the surface layers. Freshwater - includes still water such as lakes and ponds, swamps, and moving water such as springs creeks and rivers.
  29. 29. Terrestrial Ecosystems
  30. 30. Terrestrial environments vary as a result of topography, climate, availability of water, and human activity. Examples: rainforest, open forests, mountain tops, deserts, grasslands, farms and cities.
  31. 31. Population A group of living organisms of the same kind living in the same place at the same time.
  32. 32. Community Organisms living together in a particular place.
  33. 33. Habitat The habitat of an organism is the place where it lives. These can vary in size e.g. desert, under tree bark, within the digestive system of another organism.
  34. 34. Ecosystems will fail if they do not remain in balance. No community can carry more organisms than its food, water and shelter can accommodate. Food and territory are often balanced by natural phenomena such as fire, disease, and the number of predators.
  35. 35. Abiotic Factors of Ecosystems
  36. 36. Light Wind Rainfall Temperature (daily and seasonal) Topography (altitude and depth) Tides, currents and waves Water (salinity, pH and availability) Substrate (surface on which an organism grows or is attached) Space and shelter Oxygen
  37. 37. Biotic Factors of Ecosystems
  38. 38. Availability of food Number of competitors Availability of mates Number of predators Disease causing organisms Limiting factors - anything that makes it difficult for a species to live and grow, or reproduce in its environment.
  39. 39. Food Chains and Food Webs
  40. 40. Organisms have roles in ecosystems: Producers - organisms that make their own food using the energy of sunlight - plants.
  41. 41. Consumers - obtain their food by consuming other creatures - if they consume a producer then they are primary consumers or herbivores - if they consume herbivores they are secondary consumers or carnivores.
  42. 42. If they consume carnivores they are tertiary consumers or carnivores. Some species eat both producers and other consumers and they are called omnivores. Some creatures eat dead producers or consumers and are called detritivores.
  43. 43. Decomposers Bacteria and fungi that break down dead organic material. Decomposers have an important role in ecosystems - they absorb nutrients from dead organisms or waste materials and return organic matter to the soil.
  44. 44. Food chains are simple ways of representing feeding relationships among organisms. Grass > insect > spider > bird Food webs show the feeding relationship of all organisms in a particular location (food web = many food chains intertwined together).
  45. 45. Energy
  46. 46. Photosynthesis Photosynthesis is the process by which plant cells capture energy from sunlight and use it to combine carbon dioxide and water to make sugars and oxygen. Six molecules of water plus six molecules of carbon dioxide produce one molecule of sugar plus six molecules of oxygen.
  47. 47. All living things ultimately depend on this process - photosynthesis. Organisms that consume the plants gain nutrients and energy, animals that eat the plant-eaters gain energy from them, therefore the energy is passed on.
  48. 48. Respiration Respiration is the process by which cells obtain energy. Organic molecules (particularly sugars) are broken down to produce carbon dioxide and water, and energy is released.
  49. 49. Biomass and Energy Pyramids
  50. 50. Relationships
  51. 51. Predation This is a feeding relationship in which one animal (predator) obtains its food by killing another animal (prey). This relationship increases the predators chance of survival and reproduction at the expense of the preys.
  52. 52. Allelopathy The production by a plant of specific chemicals that can be detrimental or beneficial to another plant. These chemicals influence the growth and development of neighboring plants by repelling predators and parasites, or poisoning competitors. E.g. Camphor produced in leaves of the camphor laurel tree accumulates in the soil, preventing germination or growth of seedlings around each established group.
  53. 53. Parasitism A parasite obtains its food from a host. Although the host is harmed in some way, it does not necessarily die. Most free-living organisms have parasites. Many bacteria, viruses and fungi which cause diseases are parasites. Other relationships involve ticks, fleas and tapeworms.
  54. 54. Symbiosis A type of interaction between organisms where two different species live together in a close association. The association benefits at least one of them, and the other is not disadvantaged. The two types of symbiosis are commensalism and mutualism.
  55. 55. Mutualism If two organisms are more closely associated so that both benefit. Commensalism A relationship that benefits one species and does not harm the other. The organisms are not dependent on this type of relationship: they could survive without each other.
  56. 56. Competition
  57. 57. Competition is the struggle between organisms for the same resource. A particular ecosystem can support only a certain number of each type of species. Competition may be between members of the same species, or between members of different species.
  58. 58. Short term - competition reduces the chance of survival and restricts the abundance of all of the competitors.
  59. 59. Long term - one of the competitors will usually be more successful and drive out or reduce the numbers of other competitors.
  60. 60. Adaptations
  61. 61. Adaptation - a feature of an organism that makes it well suited to its environment and lifestyle.
  62. 62. Structural Adaptions A physical characteristic relating to the structure of an organisms body.
  63. 63. Physiological Adaptation Related to the way the organism functions e.g. Poisonous frogs
  64. 64. Behavioural Adaptation How an organism responds to its environment e.g. Bird migration