Y10 Biology

• Key groups of living organisms

  • Animals
  • Plants
  • Fungi
  • Protists
  • Bacteria
  • Viruses
• Animals


  • Multicellular
  • Heterotrophs
  • Reproduce sexually
• Plants


  • Multicellular
  • Autotrophs (get energy from sun via photosynthesis)
• Fungi


  • Some are multicellular, some are unicellular
  • Heterotrophs (get energy from other organisms)
  • Use saprotrophic nutrition (secrete digestive enzymes, absorb nutrients)
  • Some have a mycelium body made of hyphae
  • Some are pathogens that can cause disease
• Protists


  • Mostly unicellular
  • Some are autotrophs (can photosynthesize), some are heterotrophs (consume other organisms)
  • Some are pathogens that can cause disease (e.g. malaria)
• Bacteria


  • Unicellular
  • Some can photosynthesize but don't have chloroplasts
  • Most feed off other living or dead organisms
  • Extremely numerous, more species than all other kingdoms combined
  • Some are pathogens that can cause disease, but most are harmless or helpful
• Viruses


  • Extremely small particles, not cells
  • Have a protein coat surrounding genetic material (DNA or RNA)
  • Can only reproduce by infecting and using other living cells
  • Always act as pathogens, causing harm to host organisms
• Eukaryotes (animals, plants, fungi, protists) have DNA in chromosomes and a nucleus, while prokaryotes (bacteria) have loose DNA and no nucleus
• Viruses are not considered living organisms, they are not classified into any of the kingdoms of life
• Viruses are 10-100 times smaller than prokaryotic bacterial cells
• Cells

  The basic building blocks of life that can replicate independently
• Multicellular organisms like animals and plants contain many cells that divide to grow or replace dead cells, not to create new organisms</b>
• Bacteria are single-celled prokaryotic organisms
• Subcellular structures common to animal and plant cells

  • Cell membrane
  • Nucleus
  • Cytoplasm
  • Mitochondria
  • Ribosomes
• Plant cells

  • Have a rigid cell wall made of cellulose
  • Contain a permanent vacuole with cell sap
  • Contain chloroplasts for photosynthesis
• Bacterial cells

  • Lack mitochondria and chloroplasts
  • Have a single circular strand of DNA instead of a nucleus
  • May have additional plasmids
  • May have flagella for movement
• Photosynthesis occurs in the chloroplasts of plant cells, using chlorophyll to absorb light energy
• Mitochondria in cells break down glucose through aerobic respiration to provide energy