Characteristics and Variety

• MRS H GREN


  Movement, respiration, sensitivity, homeostasis, growth, reproduction, excretion, nutrition.
• Movement


  An action by an organism or part of an organism causing a change of position.
• Respiration


  The chemical reactions that break down nutrient molecules in living cells to release energy.
• Sensitivity


  The ability to detect or sense changes in the environment (stimuli) and to make responses.
• Homeostasis


  This is the body's ability to control internal conditions. This ensures the best conditions inside cells so reactions that are vital for life can occur.
• Growth


  A permanent increase in size and dry mass by an increase in cell number and/or cell size.
• Reproduction


  The process that makes more of the same kind of organism.
• Excretion


  The removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirements.
• Nutrition


  The taking in of nutrients which are organic substances and mineral ions, containing raw materials or energy for growth and repair of tissues, absorbing and assimilating them.
• 5 Kingdoms


  Plants, animals, fungi, protoctists and bacteria.
• Plants


  Multicellular

  Cell structure - cellulose cell wall, large permanent vacuole, cytoplasm, nucleus, chloroplasts, ribosomes, mitochondria, cell membrane.

  Nutrition - Uses the suns energy to produce own food via photosynthesis and stores energy in the form of starch and sucrose.
• Animals


  Multicellular

  Cell structure - Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes.

  Nutrition - Eat other organisms to obtain their food and store energy as glycogen and lipids (fat).

  Produce coordinated movement through their nervous system.
• Fungi


  Multicellular (e.g. mushroom) or unicellular (e.g. yeast)

  Eukaryotic

  Cell structure - Nucleus, chitin cell wall, no chloroplasts.

  Nutrition - Obtain their energy through saprotrophic nutrition (secrete digestive enzymes onto dead or living organisms and absorb digested nutrients).

  Often contain hyphae. Several hyphae form a mycelium. Reproduce using spores.
• Protoctists


  Unicellular

  Eukaryotic

  Cell structure - Various. Some have features of animal cells (e.g. amoeba) and some have features of plant cells (e.g. algae). All have a nucleus.

  Nutrition - some feed on microscopic organisms (e.g. amoeba) whereas some contain chloroplasts and photosynthesise (e.g. algae)

  They are much larger than bacteria.
• Bacteria


  Unicellular

  Prokaryotic

  Cell structure - No nucleus, has a single circular chromosome of DNA instead. Has a cell membrane, cell wall, plasmids and some contain chlorophyll.

  Nutrition - Most feed off other dead or living organisms.
• Pathogen


  A microscopic organism which causes disease to other organisms. Can be a bacteria, fungi, protoctist or virus.
• Virus

  Non-living organism

  Microscopic particle - much smaller than bacteria.

  Is a pathogen

  Is a parasite (can only reproduce inside living cells)

  No cellular structure - only has a protein coat and a strand of genetic material.

  Genetic material is either DNA or RNA.