Science

Science

biology
1. classification
  1. 1) the largest groups are called kingdoms
  2. 2) the kingdoms are then split up into smaller and smaller groups (phylum, class, order, family, genus, species
  3. 3) it can be hard to classify organisms into distinct (clear) groups. this is because some organisms seem to fit into more than one group
  4. 4) classification is important because it helps us to understand: - how organisms are related (their are evolutionary relationships) - how organisms interact (their ecological relationships)
  5. the five kingdoms
    1. 1) the plant kingdom: multicellular- cell walls made up of cellulose- uses energy from the sun to make food by Photosynthesis
    2. 2) the animal kingdom: multicellular- don`t have cell walls- feed of other organisms
    3. 3) the fungi kingdom: single-celled and multicellular organisms- cell walls made up of chitin- reproduce using spores
    4. 4) the protoctisia kingdom: single-celled organism- has a nucleus to control the cell
    5. 5) the prokaryote kingdom: single-celled organism- don`t have a nucleus to control the cell
  6. four main groups of the Arthopods
    1. myriapods: lots of legs(around 20-400 legs)- bodies are made up of segments (bands)
    2. arachnids: eight legs and no antennae
    3. crustaceans: mostly live in water- legs branch into two at the end
    4. insects: has six legs and two antennae- bodies are made up of three parts
2. pyramids of biomass and Numbers
  1. each bar on the pyramid of biomass represents the mass of living material at that particular stage of the food chain
  2. the weight of the all the organisms together
  3. pear tree- 1000kg
    1. aphids- 5kg
      1. ladybirds- 1.5kg
        partridges- 0.5kg
  4. The pear tree bar is bigger because it weighs more
  5. the pear tree is at the bottom of the pyramid because it is at the bottom of the food chain
  6. to construct a pyramid of biomass you have to use the `dry biomass` of the organism
  7. you have to remove the water from the organisms before weighing them
  8. each bar on a pyramid of NUMBERS shows the number of organisms not the mass
  9. the pyramid of biomass is shaped as a pyramid but a pyramid of numbers is not
11. energy transfer and energy flow
  1. the suns energy is the source of energy for nearly all life on earth
  2. the sun enters the food chain when plants absorb the sunlight for photosynthesis
    1. photosynthesis is where a plant uses the suns light to produce their own food
  3. all of the organisms in the food chain depend on the energy from plants
    1. animals can only get energy by eating plants, or by eating other animals that have eaten plants
  4. energy is passed through the food chain as animal eat the plants and each other
  5. at each (tropic level) energy is lost as heat from respiration
  6. energy is also lost from the food chain as waste products (poop)
    1. food is passed out as poop
    2. excretion is when the waste products of the body are released e.g as wee wee
  7. waste products and uneaten parts (bones) can become starting points for other food chains
    1. example: houseflies eat poop. YUM
  8. energy lost at 1st trophic level= 80000 kj- 10000 kj= 70000 kj
12. interactions between organisms
  1. animals compete for:
    1. food
    2. water
    3. shelter
    4. mates
  2. plants compete for:
    1. soil minarals
    2. water
    3. light
  3. organisms compete for these to survive and reproduce
  4. competitions between organisms affect:
    1. population
    2. disribution
      1. example: where they live
  5. similar animals that live in the same habitat will be closely competing for the same things
    1. example: the same food
  6. there are two types of relationships:
    1. parasitic relationships
      1. parasites live on or in a host (an animal or plant)
        they will take what they need to survive and not give anything back to the host
    2. mutualistic relationship
      1. both organisms benifit
      2. cleaner species
        example: Oxpeckers live on a buffalos back and feed on the harmful insects that live on the buffalos back
13. food chains and food webs
  1. food chains show what eats what in an ecosystem
    1. food chains always start with a producer. the producer MAKES THEIR OWN FOOD using energy from the sun
    2. producers are usually green plants, but they can be other organisms (such as algea)
    3. an animal that EATS PRODUCERS is called a PRIMARY CONSUMER
    4. a SECONDARY CONSUMER is an animal that EATS the PRIMARY CONSUMER
    5. food webs are made up of lots of food chains joined together
      1. example: grass is eaten by a snail and the hedgehog but the snail is eaten by a thrush and a hedgehog
        the snail is a primary consumer
        the thrush is a secondary consumer
        the hedgehog is both a primary and secondary consumer
    6. each stage in a food chain or web is called a TROPIC LEVEL
14. species
  1. a species is a group of organisms which can interbreed to produce fertile offspring
  2. the binomial system
    1. this system gives each species a two-part Latin name
      1. the first part is refered to as the genus that the organism belongs to
        a genus is a group of closely related species
      2. the second part refers to the species
      3. example: humans are known as Homo sapiens
        Homo is the genus
        Sapiens is the species
    2. used by scientists all over the world
  3. variation of any speccies
    1. the same species can show a great amount of vatiation
      1. dogs are the same species but have different breeds
    2. they often look alike each other and often live in similar types of habitats
      1. example: dolphins and whales
    3. closely related species may look very different if they have evolved to live in different habitats
      1. example: zebras and horses
16. predators, prey and adaption
  1. the size and population can grow depends on how much food there is for it to eat
  2. if a population of prey increases, the population of predators will also increase because there is more food
  3. as the population of predators increases, the number of prey will decrease because there are more being eaten
  4. adaptations are features or behaviours of organisms that help them to compete and survive
  5. some animals are adapted to be successful predators. others are adapted to avoid being caught as prey
  6. most predators have binocular vision
    1. this means they can judge the size and distance of their prey
  7. many predators chase their prey
    1. example: wolves often chase deer over long distances
  8. some hunt in teams
    1. example: groups of lions can kill large animals
  9. others ambush their prey
    1. example: alligators hide and wait for their prey to move closer
  10. many predators only breed when there is lots of prey available to feed their young

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	Created by Emily 1998 almost 11 years ago