bio

• Characteristics of living organisms


  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• Movement


  Action by all (or part) of an organism that causes change in position or place
• Respiration


  Chemical reactions in cells where nutrient molecules are broken down to release energy for metabolism
• Sensitivity


  Ability to detect and respond to changes in internal or external environment
• Growth


  Permanent increase in size and dry mass
• Reproduction


  Processes that make more of the same kind of organism
• Excretion


  Removal of waste products of metabolism and substances in excess of requirements
• Nutrition


  Taking in materials for energy, growth and development
• Classification system


  System to classify organisms into groups by the features they share
• Species


  Group of organisms that can reproduce and produce fertile offspring
• Binomial system


  Internationally agreed system to classify organisms using two-part scientific names showing genus and species
• Traditional classification systems reflect evolutionary relationships and are based on morphology and anatomy
• A more accurate way to classify organisms is by the sequence of bases in DNA and the sequences of amino acids in proteins
• Five Kingdoms


  • Animals
  • Plants
  • Fungi
  • Prokaryotes
  • Protoctists
• Eukaryotic


  Having membrane bound organelles, e.g. animal cells have mitochondria and a nucleus
• Prokaryotic


  Having no membrane bound organelles, e.g. bacteria
• Main features of animals

  • Multicellular
  • Cells contain a nucleus
  • Do not have cell walls
  • Feed on organic substances made by other organisms
  • Have internal digestion process
• Main features of plants

  • Multicellular
  • Cells contain a nucleus, chloroplasts, cell wall
  • Cell wall made from cellulose
  • Produce food by photosynthesis
• Vertebrate


  Animal with a backbone
• Main features of vertebrates

  • Mammals: Fur-covered skin, Mammary glands, Placenta, External ears
  • Birds: Wings, Feathers, Beak, Scales on legs and feet
  • Reptiles: Dry, scaly skin, Lay soft-shelled eggs on land
  • Fish: Scales, Fins, Gills
  • Amphibians: Smooth, moist skin, Adults live on land with lungs, Larvae live in water with gills
• Common features of microorganisms

  • Bacteria (Prokaryotes): Cell wall, No distinct nucleus, Circular chromosomes and plasmids
  • Protoctists: Variable, Can be similar to animal cells (protozoa) or plant cells (algae)
  • Fungi: Cell wall made of chitin, Contain usual organelles, Unicellular or multicellular, Hyphae have many nuclei
• Main features of invertebrates

  • Insects: Compound eyes, Three body segments, Antennae, Three pairs of legs
  • Myriapods: Antennae, Many body segments, Each segment has at least one pair of legs, Hard exoskeleton
  • Arachnids: Two body segments, Simple eyes, Four pairs of legs, No antennae, Powerful jaws
  • Crustaceans: Claws with hard serrated edges, More than four pairs of jointed limbs, Gills under shell, Two pairs of antennae
• Plant groups


  • Ferns
  • Angiosperms (flowering plants)
• Features used to classify ferns

  • Leaves called fronds
  • Fronds carry sporangia
  • Sporangia release spores
  • Reproduction occurs through spores
  • Have underground rhizomes
  • Simple, true roots
• Features used to classify angiosperms

  • Produce flowers
  • Produce fruit
  • Reproduce sexually through pollen and stigma/ovaries
  • Can be monocotyledons or dicotyledons
  • Extensive root systems
• Differences between monocotyledons and dicotyledons

  • Monocotyledons: Petals in multiples of 3, Leaves have parallel veins, e.g. wheat plants
  • Dicotyledons: Petals in multiples of 4 or 5, Have reticulated leaf veins
• Virus


  Made up of a protein coat and genetic material (either DNA or RNA), but is non-living as it does not excrete, respire, move etc. and requires a host cell to replicate
• Cell components common to all living organisms

  • Cytoplasm
  • Cell membrane
  • DNA (as genetic material)
  • Ribosomes for protein synthesis
  • Enzymes involved in respiration
• Cell components common to plant and animal cells

  • Nucleus
  • Cytoplasm
  • Mitochondria
  • Cell membrane
• Additional components found in plant cells

  • Chloroplasts
  • Vacuole
  • Cell wall
• Components found in bacterial cells

  • Cell wall
  • Cell membrane
  • Cytoplasm
  • Ribosomes
  • Circular DNA (nucleoid)
  • Plasmids
• Carbohydrate storage


  • Animals: Glycogen
  • Plants: Starch
  • Fungi: Glycogen
• New cells are produced by division of existing cells
• Specialised cell types and their functions

  • Ciliated cells: Move mucus out of trachea and bronchi
  • Root hair cells: Absorption of water and mineral ions
  • Palisade mesophyll cells: Photosynthesis
  • Neurones: Conduction of electrical impulses
  • Red blood cells: Transport oxygen around the body for respiration
  • Sperm cells: Reproduction
  • Egg cells (ovum): Reproduction
• Cell


  Group of organelles working together to perform the same function
• Tissue


  Group of cells working together to perform the same function
• Organ


  Group of tissues working together to perform the same function
• Organ system


  Group of organs working together to perform the same function
• Main plant organs


  • Leaves
  • Roots
  • Stems
  • Flowers
• Main human organ systems

  • Reproductive system
  • Circulatory system
  • Digestive system
  • Gas exchange system
  • Nervous system
  • Excretory system
  • Endocrine system