ch.1

• Characteristics of living things:

  • Movement
  • Respiration
  • Sensitivity
  • Growth
  • Reproduction
  • Excretion
  • Nutrition
• Movement: action by an organism or part of an organism that causes a change of position or place
• Respiration: the chemical reactions that break down nutrient molecules in the living cells to release energy
• Sensitivity: ability to detect and react to stimuli in the internal/external environment
• Growth: permanent increase in size and dry mass by an increase in cell number or cell size or both
• Reproduction: processes that make more of the same kind of organism
• Excretion: removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirements
• Binomial system: Kingdom, phylum, class, order, family, genus, species
• Kingdom —> species = increase in similarity
• Species = organisms can reproduce successfully
• Binomial name: Genus (first letter capital) species (underlined)
• Dichotomous key: a list of choices between two features to follow that applies, narrows down to genus then species
• Animal kingdom:

  • cells have a nucleus but no cell walls or chloroplasts
  • feed on organic substances made by other living organisms
• Plant kingdom:

  • have a nucleus, cell walls (made of cellulose) and often contain chloroplasts
  • feed using photosynthesis
  • may have roots, stems and leaves (not all plants)
• The five kingdoms:

  • Animal
  • Plant
  • Fungus
  • Prokaryote
  • Protoctist
• The fungus kingdom:

  • Muticellular (except yeast - unicellular)
  • Made up of hyphae (microscopic thread)
  • Have cell walls that are not made of cellulose
  • No chlorophyll, don’t photosynthesise
  • Feed parasitically on organic materials (feaces, human food, dead organisms)
  • Reproduce by forming spores (tiny groups of of cells with a tough protective outer covering) that are spread through wind or animals
  • Uses: antibiotics, food, making bread (yeast)
  • Harms: cause food decay and diseases (ringworm & athlete’s foot)
• The protoctist kingdom (mixed collection):

  • Usually unicellular but also may be multicellular (seaweed)
  • Contain nucleus
  • Some are plant-like (with chloroplasts and cellulose cell walls), others are animal-like
  • Some feed by photosynthesis and others feed on organic substances made by other organisms
• The prokaryote kingdom:

  • Big number of organisms
  • No nucleus
  • Harms: diseases like cholera
  • Some bacteria may carry out photosynthesis
  • Usually unicellular
  • Have cell walls, not made of cellulose
  • No mitochondria
  • Circular loop of DNA, free in the cytoplasm
  • Often have plasmids