Classification

• Amino acids


  Small molecules from which proteins are synthesised
• Amphibia


  • A class of vertebrates including frogs, toads and newts
  • Poikilothermic
  • Have four limbs, with hind feet often webbed
  • Have lungs and moist skin for breathing
  • Reproduce sexually via external fertilisation
• Animal (kingdom)


  • Biological kingdom consisting of multicellular organisms that do not have a cell wall or chloroplasts
  • Ingest and digest food for energy
• Arachnids


  • A class of arthropods including spiders, scorpions, ticks and mites
  • Have a segmented body (divided into the cephalothorax and abdomen)
  • Have four pairs of jointed legs
  • Have several pairs of simple eyes
• Arthropods


  • A phylum consisting of invertebrate animals with jointed limbs, segmented bodies and a hard external skeleton (cuticle)
  • Include crustaceans, myriapods, arachnids and insects
• Binomial system


  A universal system for naming organisms using their genus and species
• Birds


  • A class of vertebrates that are homoiothermic
  • Have four limbs (the forelimbs form wings)
  • Have beaked jaws
  • Have an outer covering of feathers over most of the body and scales on the legs and toes
  • Fertilisation occurs internally, with the female laying hard-shelled eggs
• Cell membrane


  The partially permeable barrier that surrounds a cell
• Classification


  • The organisation of organisms into groups based on their characteristics and structure
  • Classification systems may also reflect evolutionary relationships between organisms
• Crustacea


  • A class of arthropods including crabs, lobsters, prawns, shrimps, the water louse and woodlice
  • Have compound eyes and two pairs of antennae
• Cytoplasm


  The jelly-like component of cells that contains sub-cellular structures, dissolved nutrients and salts
• Dichotomous key


  A tool consisting of a series of choices (i.e. features) used to identify an unknown organism
• Dicotyledons


  • Plants that produce seeds that contain two cotyledons (embryonic leaves), resulting in two primary leaves
• DNA


  A double-stranded polymer, wound to form a double helix, that carries the genetic code
• DNA base sequence


  The sequence of bases in a molecule of DNA which can be used as an accurate method of classification. The more similar the base sequences, the more closely related the organisms
• Enzymes


  Biological catalysts that increase the rate of reaction in living organisms
• Excretion


  The process by which toxic substances and excess materials are removed from the body
• Excretion


  The process by which metabolic waste, toxic substances and excess materials are removed from the body
• Ferns


  • A group of vascular land plants that have neither seeds nor flowers and reproduce via spores from numerous sporangia. They have simple, fleshy underground stems known as rhizomes
• Fish


  • A class of vertebrates that are poikilothermic. They have a smooth-streamlined shape with fins for movement and are covered in overlapping scales. Fish have gills for breathing and reproduce sexually, with fertilisation normally occurring externally
• Fungi


  • A biological kingdom consisting of organisms made up of hyphae (long, branching filamentous structures). They reproduce asexually by producing spores
• Growth


  A permanent increase in size
• Growth


  An increase in size or dry mass that is permanent. This may be due to an increase in the number or size of cells
• Homolothermic


  Describes an organism that is warm-blooded and whose body temperature is internally regulated
• Insects


  • A diverse class of arthropods including butterflies, bees, beetles, mosquitoes, houseflies, greenfly and earwigs. They have segmented bodies (consisting of a head, thorax and abdomen), three pairs of jointed legs, one pair of antennae, compound eyes and normally two pairs of wings
• Kingdom


  The largest group of organisms identified by biologists. There are five kingdoms
• Mammals


  A class of vertebrates that are homoiothermic. They have four limbs and are characterised by the presence of hair or fur, and mammary glands. Mammals produce live young.
• Metabolism


  All of the chemical reactions that take place inside an organism.
• Monocotyledons


  Plants that produce seeds that contain one cotyledon (embryonic leaf), resulting in one primary leaf.
• Movement


  A change in position due to the action of an organism or part of an organism.
• Myriapods


  A class of arthropods consisting of millipedes and centipedes. They have a segmented body, ten or more pairs of jointed legs, one pair of antennae and simple eyes.
• Nutrition


  The process by which living organisms take in materials necessary for growth, development and energy. Animals require organic compounds, ions and water. Plants require light, carbon dioxide, ions and water.
• Plant (kingdom)


  A biological kingdom consisting of multicellular organisms that have a cellulose cell wall and can photosynthesise.
• Poikilothermic


  Describes an organism that is cold-blooded and whose body temperature varies with the temperature of the external environment.
• Prokaryote


  A biological kingdom consisting of unicellular bacteria which lack a nucleus and membrane-bound organelles.
• Protein


  A large molecule that is synthesised from amino acids.
• Protoctista


  A biological kingdom consisting of unicellular eukaryotes.
• Reproduction


  The production of more of the same type of organism.
• Reptiles


  A class of vertebrates that are poikilothermic. They have four limbs and dry, scaly skin. Reptiles reproduce sexually, with fertilisation occurring internally.
• Respiration


  Chemical reactions that take place inside cells and release energy from the breakdown of nutrient molecules. This energy is used in metabolism.