Classification

• Binomial system


  System of naming organisms, each identified by its scientific name consisting of genus and species
• Genus


  A group of similar species
• Species


  A group of closely related individuals that can produce fertile offspring
• Homo sapiens


  • Human beings
• Zea mays


  • Maize
• The classification system

  • Kingdom
  • Phylum
  • Class
  • Order
  • Family
  • Genus
  • Species
• Kingdom


  A group of similar phyla
• Phylum


  A group of similar classes
• Class


  A group of similar orders
• Order

  A group of related families
• Family


  A group of related genera
• Genus


  A group of similar and closely related species
• Species


  A group of organisms that can produce fertile offspring
• 5 Kingdoms of organisms

  • Prokaryote Kingdom
  • Protoctist Kingdom
  • Fungus Kingdom
  • Plant Kingdom
  • Animal Kingdom
• Prokaryote Kingdom - Bacteria


  • Unicellular/made up of group of cells
  • No nucleus & mitochondria
  • Circular loop of DNA in nucleoid
  • Cell wall made of peptidoglycan
  • Microscopic in size
  • Smaller ribosomes & plasmids
  • Have flagellum
• Protoctist Kingdom


  • Unicellular/made up of group of cells
  • Have nucleus & mitochondria
  • Some have cell wall & chloroplast
  • Some can perform photosynthesis
  • Some feed on other sources of food
• Plant-like protoctists

  • Chlamydomonas (algae), seaweed
• Animal-like protoctists

  • Amoeba, paramecium, plasmodium (causes malaria)
• Fungus Kingdom

  • Some are unicellular (yeast)
  • Some are multicellular (mushroom, mucor)
  • Some have thread-like hyphae (mould)
  • Cell wall made of chitin
  • Have nucleus & mitochondria
  • No chloroplast
  • Store carbohydrate as glycogen
  • Feed by saprophytic or parasitic nutrition
  • Reproduce by forming spores
• Plant Kingdom

  • Multicellular
  • Have cellulose cell wall, sap vacuole, nucleus
  • Have chloroplast; can photosynthesize
  • Store carbohydrate as starch
  • Make their own food (autotrophic)
• Non-flowering plants


  • Ferns, conifers, moss
  • Complex leaves (fronds)
  • Reproduce by spores formed from sporangia
  • Fragile adventitious roots
  • Produce gametes
  • No seed & flowers
  • Stem below ground as rhizome
• Flowering plants


  • Have roots, stem & leaves
  • Reproduce using flowers & seeds
  • Seed enclosed in fruit
  • Seed with 1 cotyledon
  • Seed with 2 cotyledons
  • Leaves have parallel veins
  • Leaves have network of veins
  • Often have 3 flower parts
  • Often have 4 or more flower parts
  • Branching root system
  • Tap root system
  • Vascular bundles randomly arranged
  • Vascular bundles arranged in a ring
• Animal Kingdom

  • Multicellular
  • Have a nucleus
  • No chloroplast & cell wall
  • Store carbohydrate as glycogen
  • Feed on other sources of food (heterotroph)
  • Red blood cells without nucleus
• Amphibians


  • Frog, toad
  • Moist & soft skin without scales
  • Adults have lungs, larvae have gills
  • Eggs laid in water, external fertilization
  • Tadpole stage in water, adult on land
  • Eggs without shell
  • 4 limbs
• Red blood cells of frog have nucleus
• Reptiles


  • Crocodile, snake, lizards, turtles, iguana
  • Live mainly on land
  • Lay eggs with soft shell
  • Lungs for breathing
  • Internal fertilization
  • Cold-blooded
  • 4 limbs each with 5 toes, except snakes
  • Dry & scaly body
• Birds

  • Pigeons, kestrel, parakeet
  • Have feathers
  • Eggs with hard shell
  • Have beak & wings
  • 4 toes with claws
  • 4 heart chambers
  • Forelimbs modified as wings
  • Warm-blooded
• Mammals


  • Human, dogs, sheep
  • Skin covered with hair
  • Give birth to young
  • Feed young with milk from mammary glands
  • Have lungs
  • Different types of teeth
  • Have sweat glands
  • Warm-blooded
  • 4 heart chambers
• Red blood cells of mammals do not have nucleus
• Platypus is a mammal that lays eggs
• Bats have wings but they are mammals
• Arthropods


  • Jointed legs
  • Hard & rigid exoskeleton (cuticle) formed by chitin
• Crustaceans


  • Crabs, lobster, shrimp
  • Mainly aquatic
  • More than 4 pairs of jointed legs
  • Breathe through gills
  • Have 2 pairs of antennae & compound eyes
  • Have claws
• Insects

  • Bees, flies, mosquitoes
  • 3 pairs of jointed legs
  • 2 pairs of wings
  • Segmented body (head, thorax & abdomen)
  • Firm exoskeleton
  • Breathe through tracheae
  • Mainly terrestrial
• Myriapods

  • Centipede, millipede
  • Segmented body & distinct head
  • Simple eyes & 1 pair of antennae
  • Millipedes are herbivores with 2 sets of legs per segment
  • Centipedes are carnivorous with 1 pair of legs per segment
• Arachnids


  • Spiders, ticks, scorpions
  • Carnivorous
  • Body divided into cephalothorax & abdomen
  • 4 pairs of jointed legs
  • 1 pair of pedipalps to capture prey
  • No antennae
• Viruses

  • Smallest of all organisms
  • Visible only under electron microscope
  • Genetic material of RNA (retroviruses) or DNA
  • Surrounded by protein coat
  • No organelles (nucleus, cytoplasm, cell membrane)
  • Parasitic, need a host to reproduce