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National 5 Biology Key Area 1: Biodiversity and the Distribution of Life

Learn about the importance of biodiversity and its impact on human life. Discover the factors that affect biodiversity, including biotic and abiotic factors, natural hazards, and human influences. Explore examples and understand the consequences of habitat destruction, deforestation, overfishing, intensive agriculture, genetic pollution, and oil spills.

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National 5 Biology Key Area 1: Biodiversity and the Distribution of Life

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  1. National 4 Biology Key Area 2: Impact of population growth and natural hazards on biodiversity National 5 Biology Key Area 1: Biodiversity and the Distribution of Life

  2. National 4&5 outcomes By the end of the lesson you will be able to ….. • Define the word Biodiversity. • Explain why a high level of biodiversity is important to humans

  3. Biodiversity Life Variety Biodiversity is the total variety of all living things on Earth David Attenborough - Wonderful World – BBC 2:04

  4. Why is high biodiversity important? Human rely on high biodiversity for numerous reasons: • Regulation of ecosystems: • pollinate crops • absorbs CO2 gases • Products: • Food • Raw materials • Medicines • Cultural Benefits • recreation and tourism

  5. National 4&5 outcomes Can you now …. • Define the word biodiversity. • Explain why a high level of biodiversity is important to humans.

  6. Quick Question 1. The total variety of all living things on Earth is described as • An ecosystem • Biodiversity • A population • Competition 2. Give two reasons why humans depend on a high level of biodiversity.

  7. National 4&5 outcomes By the end of the lesson you will be able to ….. • Give examples of factors that affect biodiversity

  8. Factors that affect biodiversity 1. Biotic and Abiotic Factors Relating to living things Relating to NON -living things • Food availability • Predation • Grazing • Disease • Competition for resources • Moisture • Light Intensity • pH • Temperature Can change variety of fish species in a pond

  9. 2. Natural Hazards • Many natural disasters (e.g. forest fires) can decrease biodiversity.

  10. 3. Human Influences

  11. “Habitat loss is probably the greatest threat to the variety of life on this planet today” WWF 2013 • removes an animals source of food and their shelter. • Many animals will die of starvation or exposure. • Habitat destruction – decreases biodiversity by destroying where an organism lives.

  12. 2. Deforestation – decreases biodiversity by removing large areas of forest Deforestation in Kenya • In 1963 10% of Kenya was rich forest • In 2006 only 1.7% remained as untouched forest • Demand for hardwoods • Employment & cash crops Deforestation (3:49)

  13. 3. Over fishing– decreases biodiversity by catching too many fish and destroying habitats. • Food and Agriculture Organization (FAO) estimate, over 70% of the world’s fish species are either fully exploited or depleted Overfishing the consequences (2:34)

  14. 4. Intensive agriculture– decreases biodiversity by using machinery, pesticides and herbicides to produce large quantities of food crops. Intensive agriculture lowers biodiversity by • Encouraging large areas of ‘monoculture’ where only one type of crop is grown • Increased use of pesticides and herbicides • Eradication programmes (e.g. wolves and badgers removed to protect livestock)

  15. 5. Genetic Pollution – decreases biodiversity by introducing new genes into wild populations. • Genetic pollution occurs when genes from GM crops/animals are passed into wild populations. • This can reduce biodiversity because the modified organisms could out compete their ‘wild’ relative forcing them into extinction. “In 2002 farmers' traditional maize varieties in two remote Mexican states, Oaxaca and Puebla, had been contaminated with DNA from genetically modified (GM) maize. Genetic pollution is alarming both because it is illegal to grow GM maize in Mexico” (http://www.foodfirst.org/en/node/53)

  16. 6. Oil or chemical spills– decreases biodiversity by introducing toxic chemicals that change the environment. Hawaii: molasses spill • 12th September 2013 • 233,000 gallons of molasses spill into the water of Honolulu Harbour from a pipeline supplying tankers • Equivalent to 5,500 barrels of oil Honolulu molasses spill (2:12)

  17. National 4&5 outcomes Can you now …. • Give examples of factors that affect biodiversity

  18. Quick Question • Name one biotic factor that can affect biodiversity. • What effect does deforestation have on biodiversity? • Describe the effect habitat destruction has on biodiversity. Food Availability or Predation or Grazing or Disease or competition It DECREASES biodiversity It also DECREASES biodiversity because it destroys where an organism lives. Organisms are left exposed and/or starving

  19. By the end of the lesson you will be able to ….. • Give examples of resources that animals and plants compete for • Define interspecific and intraspecific competition and give examples of each

  20. Competition • Habitats have limited supplies of the resources needed by living organisms. • Organisms must compete with others to get enough of these resources.

  21. Plants compete for:

  22. Animals compete for:

  23. Different types of competition • Interspecific competition is when individuals of different species compete for the same resource in an ecosystem • Intraspecific competition is when individuals of the same species compete for exactly the same resources

  24. An example of Interspecific Competition The Grey squirrel vs. The Red squirrel Red squirrel – 4:44

  25. Competition between members of different species • Red and Grey squirrels compete for the same food... • North American Grey squirrels were introduced to Britain and competes with the native red squirrel • The grey squirrels competes more aggressively for food and have become more widely distributed • Therefore the red squirrel is now in decline! vs.

  26. Can you now …. • Give examples of resources that animals and plants compete for • Define interspecific and intraspecific competition and give examples of each

  27. Quick Question • What resources would animals compete for? • What is interspecific competition? • Which type of competition is fiercest, interspecific or intraspecific? Why? Food/Mates/Shelter/ Territory When members of different species compete for the same resource Intraspecific

  28. Quick Questions • Name one human activity that affects Biodiversity • Describe how this activity affects biodiversity. • Habitat destruction • Deforestation • Intensive agriculture • Over-fishing • Genetic pollution • Oil or chemical spills. It causes it to decrease because ……..

  29. By the end of the lesson you will be able to ….. • Define the term endangered species. • Give examples of ways to protect biodiversity • Give the advantages and disadvantages of reintroducing a species to an environment

  30. Endangered Species Species in danger of becoming extinct. Ways to prevent extinction: • Wildlife reserves • Captive breeding programmes • Re-introduction of animals Yellowstone: the return of the wolf 5:42

  31. What factors contribute to animals becoming extinct? Factors that contribute to species becoming extinct…. • Hunting or culling. • destruction of habitat • outbreaks of disease • declining birth rates • changes to their food source • adverse weather • pollution

  32. Can you now …. • Define the term endangered species. • Give examples of ways to protect biodiversity • Give the advantages and disadvantages of reintroducing a species to an environment

  33. Quick Questions • What is the difference between a biotic and abiotic factor? • Sort the following factors into biotic and abiotic Biotic factors relate to living things, Abiotic factors relate to non living things Grazing Temperature pH Rainfall Predation Disease

  34. By the end of the lesson you will be able to ….. • Describe how the biotic factors, such as predation, affect biodiversity. • Interpret (describe the patterns shown by) predator-prey graphs.

  35. Predation • Remember! • Predator – an animal that consumes another animal for energy • Prey – an animal that is hunted and consumed by another animal for energy • Can affect biodiversity • The numbers of prey and predators are very closely linked

  36. Predator-Prey Interactions • Ladybirds and aphids

  37. Predator-Prey Interaction • The number of predators depends on the number of prey (and vice versa!). • Predator numbers increase when there is lots of prey. • Prey numbers increase when there are low numbers of predators.

  38. Can you now …. • Describe how the biotic factors, such as predation, affect biodiversity. • Interpret (describe the patterns shown by) predator-prey graphs.

  39. Quick Questions • Define the word prey. • Define the word predator. Animal that is hunted and eaten by another animal for energy An animal that hunts and eats other animals for energy 3. Which line in the graph shows prey numbers? 4. Explain why predator numbers are increasing in the highlighted area of the graph A B A More food available!

  40. By the end of the lesson you will be able to ….. • Define the word biome. • Name (at least) three different biomes. • Give two factors that influence the global distribution of biomes on earth.

  41. Biologists divide the world into large natural regions called biomes. • These are two you may have heard of …. Desert Rainforest Introduction to Biomes 3:09

  42. How many biomes are there? • Depends on who you ask! • For National Biology we will be looking at 8 different Biomes You are not required to know the individual biomes by name but must be able give the definition for Biomes and name two factors that affect their distribution.

  43. Biomes • Biomes are the various regions of our planet distinguished by their similar climate, fauna (animal life) and flora (plant life).

  44. Global distribution of biomes can be influenced by … • Temperature • Rainfall

  45. Can you now …. • Define the word biome. • Name (at least) three different biomes. • Give two factors that influence the global distribution of biomes on earth.

  46. Biomes of Our Earth: Major Life Zones .

  47. Quick Questions • Define the word prey. • Define the word predator. Animal that is hunted and eaten by another animal for energy An animal that hunts and eats other animals for energy 3. Which line in the graph shows prey numbers? 4. Explain why predator numbers are increasing in the highlighted area of the graph A B A More food available!

  48. Quick Questions Define the word Biome. Name three different biomes State the two environmental factors that control the distribution of biomes. The various regions of our planet distinguished by their similar climate, fauna (animal life) and flora (plant life). Any three from ….. Tundra, Taiga, temperate deciduous forest, tropical savannah, temperate grassland, desert, Mediterranean, tropical rainforest. Rainfall and temperature

  49. By the end of this lesson you will be able to… • Define the word Ecosystem • Name the different components contained within an ecosystem

  50. Biomes • We have looked at biomes. • Biomes are the various regions of our planet distinguished by their similar climate, fauna (animal life) and flora (plant life). • Huge!! Within these biomes there are smaller areas called ecosystems

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