Characteristics of Living Organisms (Cambridge International IGCSE Biology)

Spec point — 1.1.1 · (a) movement as an action by an organism or part of an organism causing a change of position or place (b) respiration as the chemical reactions in cells that break down nutrient molecules and release energy for metabolism (c) sensitivity as the ability to detect and respond to changes in the internal or external environment (d) growth as a permanent increase in size and dry mass (e) reproduction as the processes that make more of the same kind of organism (f) excretion as the removal of the waste products of metabolism and substances in excess of requirements (g) nutrition as the taking in of materials for energy, growth and development

Characteristics of living organisms

• All living organisms (animal, plant, fungus, prokaryote and protoctist) demonstrate the characteristics:

  • movement: an action by an organism or part of an organism causing a change of position or place
  • respiration: the chemical reactions in cells that break down nutrient molecules and release energy for metabolism
  • sensitivity: the ability to detect and respond to changes in the internal or external environment
  • growth: a permanent increase in size and dry mass
  • reproduction: the processes that make more of the same kind of organism
  • excretion: the removal of the waste products of metabolism and substances in excess of requirements
  • nutrition: the taking in of materials for energy, growth and development

Exam Hint You can use this mnemonic to help you remember the 7 characteristics that all living organisms demonstrate:

MRS GREN

• Movement
• Respiration
• Sensitivity
• Growth
• Reproduction
• Excretion
• Nutrition

Some common misconceptions to watch out for:

• Bacteria (a type of prokaryote) also show all of the characteristics listed above
• Confusing the living characteristic excretion with egstion, which is the removal of undigested food from the body as faeces