Biology

• Characteristics of Living Things


  • Grow
  • Respire
  • Display irritability
  • Move
  • Require nutrition
  • Excrete
  • Reproduce
  • Are made up of cells
  • Adapt and evolve
  • Maintain homeostasis
• Growth


  Increase in size and number of cells. All organisms grow, change and become more complex in a process called development.
• Respiration


  Process where food is utilised to store energy in a chemical called Adenosine Triphosphate (ATP)
• Irritability


  Ability of a living thing to respond to changes (stimulus) in the environment
• Movement


  All living things are able to move on their own accord. Animals move to find food, shelter or in response to their environment. Plants are able to move parts of themselves towards light and water.
• Nutrition


  Nutrients are required by all living things to obtain energy and build new protoplasm. Plants obtain nutrients from photosynthesis, while animals obtain nutrients by eating other plants and animals.
• Excretion


  Process of removing metabolic waste products from living things. The importance is to ensure homeostasis as the accumulation of such waste products can be toxic and harmful to the organism.
• Reproduction


  All living things can produce new individuals, thus ensuring the continuation of the species. Genetic material found in the nucleus of cells in the form of DNA is replicated and passed down from parent to their offspring. It determines the organism's characteristics and so the characteristics of the parent are passed on to the offspring.
• Cells


  Cells are the basic unit of life. Unicellular organisms are composed of only one cell. Multicellular organisms are composed of many cells. In multicellular organisms, cells are grouped into different levels of organisation from tissues to organ systems.
• Adaptation and Evolution


  Adaptations are modifications enabling an organism to survive in an environment. These adaptations come about through evolution, the process by which a species changes through time.
• Homeostasis


  To remain alive, all living things maintain a constant internal environment despite changes in the external environment. An example is excretion in humans, where waste products formed during metabolic reactions are removed from the body. All organ systems are involved with homeostasis.
• Species


  The basic unit of classification. Members of a single species have a common ancestry, very similar genes and therefore have similar physical, biochemical and behavioral features, and can interbreed to produce fertile offspring.
• Species change and evolve over time, so physical appearance is not a reliable tool to distinguish different species as different species can look very similar in some instances
• Classification


  The sorting of things into groups. Grouping living things based on their similarities provides a better understanding of their lives, patterns, behaviours, environment and evolution.
• Methods of Classification


  • Artificial classification uses observable characteristics to classify organisms without taking into account the evolutionary origins
  • Natural classification groups organisms based on shared features from their ancestors and reflect their evolutionary descent
• Taxonomic Hierarchy


  The system used to classify organisms, structured as a hierarchy where organisms are classified into large groups, which are then subdivided into smaller groups. Each group is called a taxon.
• Binomial Nomenclature


  Organisms are identified by two names, the genus and species name. The names are often based on Latin or Greek and is used and understood by scientists all over the world.
• Five Kingdoms


  • Protoctista
  • Fungi
  • Plantae
  • Animalia
  • Prokaryotae
• Eukaryotes


  Organisms whose cells contain a nucleus and membrane-bound organelles
• Prokaryotes


  Organisms whose cells do not contain distinct nucleus or membrane-bound organelles