Success Criteria Life on Earth - National 5 Colour the box at the side of each objective: RED I don t know much about this or am confused by it. AMBER I know a bit about this but do not feel I know it well. GREEN I am very confident that I know this 1. Biodiversity and the distribution of life. 1. Know that biotic and abiotic factors affect biodiversity in an ecosystem. 2. Give examples of human activities which can affect biodiversity in an ecosystem (pollution, habitat destruction etc) 3. State that grazing, competition, disease, food availability and predation are examples of biotic factors. 4. State that temperature, light intensity, moisture and ph are abiotic factors. 5. Know that a Biome can be described as various regions of our planet with a similar climate, fauna (animal life) and flora (plant life). 6. Understand that global distribution of biomes is influenced by temperature and rainfall (specific examples of Biomes are not needed). 7. State that an ecosystem is composed of all living things (the community) in a particular habitat and their non-living environment. 8. Understand that the niche of an organism is the role it plays within a community (including the use it makes of resources such as light, temperature and nutrients as well as its role in competition, parasitism and predation). 1.
2. Energy in Ecosystems. 1. Know that in transfers from one level to the next in a food chain, 90% of energy is lost. 2. Understand that the energy is lost as heat, movement or production of undigested materials. 3. Know that 10% of the energy produced is used for growth (the 10% that is passed on). 4. Know and understand the possible shapes all 3 types of pyramid take. 5. State that a pyramid of number shows the total number of organisms at each stage in a food chain. 6. State that a pyramid of biomass shows the total mass of all the organisms at each stage in a food chain. 7. State that a pyramid of energy shows the energy available at each stage in a food chain. 8. Understand that animal and plant proteins are produced using nitrogen from nitrates. 9. Decomposers (bacteria and fungi) break down the protein in dead organisms and their waste products and convert them to ammonium compounds. 10. Nitrifying bacteria in the soil convert ammonium compounds into nitrites and then nitrates. 11. The process of converting other compounds into nitrates is called nitrification. 12. Legumes are a group of plants, including peas, beans and clover, which have swellings called root nodules on their roots. 2.
13. The root nodules of legumes contain nitrogen fixing bacteria. 14. Nitrogen-fixing bacteria are also found living free in the soil. 15. Nitrogen-fixing bacteria convert nitrogen gas from the air into nitrates. 16. The conversion of nitrogen gas to nitrates is called nitrogen fixation. 17. Lightening also converts atmospheric nitrogen to nitrates, which then dissolve in the rain and fall to the ground. 18. There are also denitrifying bacteria living free in the soil. 19. Denitrification is the conversion of nitrates into nitrogen gas, which is released back into the air. 20. Animals obtain the nitrogen required to produce protein by consuming plants. 21. Know that in order to be defined as the same species, organisms should have similar characteristics and be able to breed to produce fertile offspring. 22. Define a population as the number of organisms of the same species which live in a particular habitat. 23. Know that a producer is an organism which can synthesise (make) its own food. 24. Understand that a consumer is an animal which must eat other organisms to gain energy. 25. Know that a herbivore is an organism which only eats plants. 26. Define a carnivore as an organism which eats other animals to gain energy. 27. Know that an omnivore is the term used to describe an organism which eats both animals and plants. 3.
biotic 28. Know that Interspecific competition is individuals of different species requiring similar resources in an ecosystem. 29. Know that Intraspecific competition is individuals of the same species requiring the same resources. 30. Understand that intraspecific competition is therefore more intense than interspecific competition. 3. Sampling techniques and measurement of biotic and abiotic factors. 1. Know that quadrats can be used to sample organisms that are fixed (small plants) or partly fixed (slugs) to a surface. 2. Understand that pitfall traps are used to sample invertebrate animals that move around on the soil. 3. Know the sources of error for both pitfall traps and quadrats. 4. Know how to use and construct paired statement keys to identify the organisms found during sampling techniques. 5. Describe how to measure light intensity, temperature, ph and soil moisture (abiotic factors affecting distribution in an ecosystem). 6. Know the sources of error when measuring abiotic factors. 4.
4. Adaptation, natural selection and the evolution of a new species. 1. Know that a mutation is a random change to genetic material. 2. Know that mutations can be neutral or confer an advantage or disadvantage to an organism. 3. Understand that mutations are spontaneous. 4. Understand that mutations are the only source of new variation in a species. 5. Know that environmental factors, like radiation, high temperatures and chemicals, can increase the chance of a mutation occurring. 6. New alleles produced by mutation allow plants and animals to adapt to their environment. 7. These adaptations can by structural or behavioural. 6. Be aware that variation within a population makes it possible for a population to evolve over time (in response to a changing environment). 7. Know that all species produce more offspring than the environment can provide for (due to limited resources). 8. Understand that members of a species show variation through different mutations they carry. 9. Know that a struggle for survival then follows. 10. Natural selection makes sure that the organisms who are best suited to their environment (because of the variation) survive AND REPRODUCE. 11. Favourable genes are passed on, passing on the selective advantage to the offspring. 12. Understand that natural selection occurs when there are selection pressures. 13. Know examples of selection pressures to include predation, disease, rainfall and temperature. 5.
14. State that speciation is the term used to describe the formation of a 1 or more new species from 1 original species. 15. Know that speciation occurs after part of a population becomes isolated by an isolation barrier. 16. Give examples of isolation barriers to be; geographical, ecological or reproductive. 17. Know the steps of speciation: 1. ISOLATION - Population becomes isolated. 2. MUTATION - Different mutations occur in each sub-population (because mutations are random). 3. NATURAL SELECTION - Natural selection selects for different mutations in each group (due to different selection pressures). 4. SPECIATION -Each sub-population evolves until they become so genetically different they are two different species. 5. Human impact on the environment. 1. Understand that as the human population increases this requires an increased food yield. 2. Know that fertilisers are often used to improve the growth of a crop (and therefore increase the yield). 3. Understand that fertilisers can leach from the fields into fresh water. 4. Know that the fertiliser causes increase in the growth of algae, leading to an algal bloom. 5. Explain why algal bloom leads to a reduction in the oxygen levels of water: 1. Algal bloom reduces light levels killing aquatic plants. 2. The dead plants, as well as dead algae, become food for bacteria. 3. The bacteria increase greatly in number. 4. Large quantities of oxygen are used up by the bacteria. 5. Oxygen availability is reduced for other organisms. 6.
6. Know that pesticides are sprayed onto crops to kill a range of pests and increase the crop yield. 12. Know that genetically modified (GM) crops may be an alternative to the use of fertilisers. 7. Understand that some pesticides are non-biodegradable (they don t naturally break down). 8. Know that non-biodegradable pesticides can accumulate (build up) in the bodies of organisms over time. 9. Understand that as pesticides accumulate, they can become toxic and sometimes lethal. 10. State that an indicator species is a species that by their presence or absence indicate the quality of the environment (the levels of pollution). 11. Know that Biological control may be an alternative to the use of pesticides. 7.