all science coordinated igcse

• Features that all living organisms have in common

  • Movement
  • Respiration
  • Sensitivity
  • Nutrition
  • Excretion
  • Reproduction
  • Growth
• Organelles that both animal and plant cells share

  • Cell membranes
  • Cytoplasm
  • Nuclei
  • Ribosomes
  • Mitochondria
• Additional organelles found in plant cells

  • Cell wall
  • Vacuole
  • Chloroplasts
• Nucleus


  Controls the activities of the cell
• Cytoplasm


  Where chemical reactions take place
• Cell membrane


  Controls what enters and leaves the cell
• Cell wall


  Made of cellulose, protects and supports the cell
• Vacuole


  Filled with cell sap, helps maintain cell structure
• Chloroplasts


  Contain chlorophyll, where photosynthesis takes place
• Red blood cell


  • Transports oxygen around the body
  • Contains hemoglobin which binds to oxygen
  • Biconcave disc shape for increased surface area
  • No nucleus to allow more hemoglobin
  • Extremely flexible to pass through capillaries
• Ciliated cell


  • Lines the trachea
  • Contains cilia which waft mucus and bacteria out of the airway
• Sperm cell


  • Made by testes
  • Fuses with ovum in fertilization
  • Has a flagellum tail to swim
  • Middle section contains many mitochondria for energy
  • Head contains acrosome with digestive enzymes
  • Haploid nucleus with one set of chromosomes
• Ovum


  • Involved in reproduction
  • Haploid nucleus with one set of chromosomes
  • Has a jelly coat that changes after sperm penetration
• Root hair cell


  • Absorbs water and minerals
  • Has a hair-like shape to increase surface area
• Palisade layer


  • Contains many chloroplasts to absorb sunlight for photosynthesis
• Converting units


  1. Pico to nano: x1000

  2. Nano to micro: x1000

  3. Micro to milli: x1000

  4. Milli to centi: x100

  5. Centi to metre: x100

  6. Metre to kilo: x1000
• Diffusion is the net movement of particles from high to low concentration
• Osmosis is the net movement of water from high to low water potential across a partially permeable membrane
• Organic compounds


  • Carbohydrates
  • Lipids
  • Proteins
• Carbohydrates


  Contain carbon, hydrogen and oxygen
• Proteins


  Contain carbon, hydrogen, oxygen, nitrogen and sulfur
• Nucleic acids


  Contain carbon, hydrogen, oxygen, nitrogen and phosphorus
• Types of carbohydrates


  • Monosaccharides
  • Polysaccharides
• Polysaccharides


  • Cellulose
  • Starch
  • Glycogen
• Protein


  A chain of amino acids whose order is determined by genes
• Enzymes


  • Biological catalysts that speed up reactions without being used up
  • Have an active site where the substrate binds
  • Form an enzyme-substrate complex which then splits to form products
• Increasing temperature


  Increases enzyme activity
• Extreme temperature or pH

  Denatures enzymes
• Photosynthesis


  Process by which green plants make their own food
• Limiting factors for photosynthesis

  • Carbon dioxide
  • Light intensity
  • Temperature
• In the early morning

  Low temperatures and low light levels limit the rate of photosynthesis
• At midday


  Carbon dioxide levels become the most likely limiting factor for photosynthesis
• Gas exchange in plants

  1. Carbon dioxide diffuses into the leaf through stomata

  2. Oxygen diffuses out of the leaf

  3. At night, more oxygen enters the leaf due to respiration
• Photosynthesis produces glucose, which is used by plants to make fats, proteins, starch, and cellulose
• Leaf structure


  • Large surface area to absorb light
  • Thin to allow gases to diffuse easily
• Layers of a leaf

  • Waxy cuticle
  • Upper epidermis
  • Palisade mesophyll
  • Spongy mesophyll
  • Vein
  • Lower epidermis
  • Guard cells and stomata
• Nitrates


  Used by plants to build proteins
• Magnesium


  Used by plants to manufacture chlorophyll
• Deficiency in magnesium leads to yellow leaves, deficiency in nitrates leads to stunted, poorly grown plants
• Nutrients in a balanced diet

  • Carbohydrates
  • Fats
  • Proteins
  • Minerals
  • Vitamins
  • Water
  • Fiber