bio

• Biology


  The study of life and living organisms
• Characteristics of living organisms

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


  A change of position or place
• Respiration


  Break down of glucose to produce energy in cells
• Sensitivity


  Detect and respond to surrounding changes
• Growth


  A permanent increase in size
• Excretion


  Removal of waste from the body (urine in human, oxygen in plants)
• Nutrition


  Taking in food
• Reproduction


  Make more of the same species
• Biologists use 7 characteristics to prove whether something is alive or not
• Growth


  • All organisms begin small and get larger, by the growth of their cells and by adding new cells to their bodies
• Movement


  • All organisms are able to move to some extent. Most animals can move their whole body from place to place, and plants can slowly move parts of themselves
• Sensitivity


  • All organisms pick up information about changes in their environment, and react to the changes
• Excretion


  • All organisms produce unwanted or toxic waste products as a result of their metabolic reactions, and these must be removed from the body
• Reproduction


  • Organisms are able to make new organisms of the same species as themselves
• Nutrition


  • Organisms take substances from their environment and use them to provide energy or materials to make new cells
• Respiration


  • All organisms break down glucose and other substances inside their cells, to release energy that they can use
• Figure 1.1 shows the characteristics of living organisms
• Classification systems


  Traditional and modern methods to show evolutionary relationships
• Traditional classification


  Based on morphology (external bodies) and anatomy (internal body structure)
• Modern classification


  Based on DNA sequence and protein sequence

  
• DNA is the complex molecules from which our chromosomes are made. It is the genetic material, passed on from one generation to the next

  
• DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T)

  
• The more similar base sequences they have, the more closely related they are
• Proteins


  Made up by amino acids, the more similar the amino acid sequences, the more closely related the species are to one another
• How DNA barcoding is useful in the conservation of animals

  • Accurate identification of animals
  • Cheap, easy, quick, efficient
  • Useful for distinguishing characteristics
  • Identify previously unknown species
  • Identify threatened/endangered species

  
• It is better to use DNA sequences/protein sequences/modern methods for classification because they provide more accurate information about evolutionary relationships

  
• Species


  A group of organisms that can reproduce to produce fertile offspring
• Binomial (two-name) system


  Each species has a scientific name made up of its genus and species, e.g. Canis lupus
• The table shows how a monarch butterfly and a giant pangolin are classified

  
• Five kingdoms of living organisms

  • Animal
  • Plant
  • Fungus
  • Prokaryote
  • Protoctist
• Animals


  • Multicellular, have a nucleus but no cell walls or chloroplasts, feed on organic substances made by other living organisms
• Plants


  • Multicellular, have a nucleus, cell walls made of cellulose and contain chloroplasts, feed by photosynthesis, may have roots, stems and leaves
• Fungi


  • Multicellular, have a nucleus, have cell walls not made of cellulose
• Viruses have a protein coat and genetic material
• Five Kingdoms of Living Organisms

  • Animal
  • Plant
  • Fungus
  • Protoctist
  • Prokaryote
• Animals


  • Multicellular
  • Have a nucleus, but no cell walls or chloroplasts
  • Feed on organic substances (C, H) made by other living organisms
• Plants


  • Multicellular
  • Have a nucleus, cell walls made of cellulose and contain chloroplasts
  • Feed by photosynthesis
  • May have roots, stems and leaves
• Fungi


  • Multicellular (many-celled)
  • Have nucleus
  • Have cell walls, not made of cellulose
  • Do not have chlorophyll
  • Feed by saprophytic or parasitic nutrition (organic material like faeces, human foods and dead plants or animals)
• Protoctists


  • Multicellular or unicellular
  • Cells have a nucleus
  • Cells may or may not have a cell wall and chloroplasts
  • Some feed by photosynthesis and others feed on organic substances made by other organisms