B3 Life on Earth

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  • Created by: JAMEZJB
  • Created on: 11-03-16 13:07
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  • B3 Life on Earth
    • What is Adaptation?
      • A species is a group of organisms that breed together to produce fertile offspring. They have features that help them survive in their environment. These are adaptations. Adaptation increases the chance of survival.
    • How do spices interact?
      • Within a place where the organism lives – its habitat. There is competition. Animals – food, shelter and mating Plants- space and light Species rely on each other and their environment. Species are independent A food web shows what eats what in a habitat. Changes in the food web can affect other animals. This could result in extinction of a species.
    • How plants do use energy from the sun?
      • Plants absorb 1-3% of light from the sun that fall on their leaves. Photosynthesis uses this energy. This produces a chemical reaction that makes plant cells and store energy. Plants are producers. Animals, bacteria and fungi rely of plants for food. All life is dependent on energy from the sun.
    • How is energy transferred?
      • Energy is transferred by... When consumers eat other organisms When decomposers and detritions eat dead organism Only small amounts of energy are passed on the food web. The rest is lost through Using the life processes Escapes as heat Is excreted as waste Cannot be eaten and is passed on to decomposers Because so much energy is lost, food chains do not have more than 4 species. 32/160 x 100 = 20%
    • How is carbon recycled?
      • It is recycled by the environment. Take out co2: photosynthesis, dissolved in water, animals respiration by breaking down glucose. Return co2: decomposition, combustion, volcanic activity.
    • How is nitrogen recycled?
      • Microorganisms are vital to the nitrogen cycle. Decomposer bacteria break down dead organisms Nitrogen fixing bacteria in some roots convert into nitrogen compounds, including nitrates. Plants use nitrates to make protein. Animals digest plants to make animal proteins. Denitrifying bacteria break down nitrates into the soil and release nitrogen into the air. This is denitrification.
    • How has life evolved?
      • Life began 3500 years ago. All species evolved from simple living things. Fossil and DNA analysis provide evidence for evolution. Variation between individuals of species Genetic variation is caused by mutations to the genes. These are then passed on to the offspring. This produces new features. Causes of evolution: Mutations Natural selection Environmental changes Isolation Natural selection is different from selective breeding in which humans choose characteristics of plants and animals.
    • Monitoring the environment
      • Scientist use indicators to measure environmental change. Living indicators: phytoplankton- measure ocean temperatures Lichens- air quality Mayfly nymphs monitor oxygen levels in rivers Non living indicators: Nitrate levels in streams, rivers and lakes Co2 levels and temperature in air and oxygen
    • How did Darwin develop his theory?
      • Developed his theory by natural selection. He made many observations and used creative thoughts to explain. His theory was better than Lamarck’s as it fits modern genetics and was supported by more evidence.
    • How do we classify organisms?
      • Huge variety of life on earth. These include organisms that are animals, plants a microorganism within theses species there are many variations. This is biodiversity. Scientist use DNA, similarities and differences of an organism to put into groups. This is classification. Classification helps make sense of the diversity of life and helps show how animals evolved. Biggest group of animal kingdom > animals > vertebrates> mammals> carnivores> cats
    • Why does biodiversity matter?
      • Sustainability means meeting the needs of people today without damaging earth for future people.Preserving biodiversity is a vital part of living sustainably:Wide variety of crops to develop new varieties of food crops We use plant substance for medication, Growing single crops in a large field (monoculture) is not sustainable. These crops can easily be attacked by pests and disease. But more plants are likely to become resistant to diseases.
    • Why do species become extinct?
      • If all members of the species die out, that species is extinct. Species become extinct by: changes in the environment which cannot be adapt to Competition Changes in the food web
    • Why is packing a problem?
      • The production and transport of packing uses allot of energy. As well as allot of waste. This waste takes up space in land fill sites.  Biodegrablable packaging often fails to decompose because of the levels of oxygen. It is more sustainable to reuse packaging.




Are you sure this is B3 on the OCR board?? I have my revision book next to me, and it says B2 contains everything you have got on your mind map. (just want to add - there is nothing wrong with your mind map, it is perfect!)

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