Science: Biology

• All living things


  • Made up of one or more cells
• Types of organisms

  • Trees
  • Elephants
  • Moss
  • Paramecium
• Single-celled or unicellular organisms


  Do many of the same things as multi-cellular organisms (grow, eat, excrete, reproduce)
• Types of cells


  • Prokaryotes (without nuclei, DNA floats freely)
  • Eukaryotes (with cell nucleus protecting DNA)
• Paramecium

  • 50 thousandth of a millimeter long
  • Has an especially thick flagellum that pushes it forward
• Cilia

  • Hair-like structures that are effective motors for moving through water, walking over surfaces, bringing food toward the cell
• Amoeba

  • Moves by reaching out its flexible membrane and forming a pseudopod (false foot)
  • Cytoplasm streams into the pseudopod and the rest of the cell follows
• Organelles within a single cell

  • Carry out life processes such as digestion, respiration, water regulation
• Cell membrane


  Controls the flow of nutrients, oxygen and waste into and out of the cell
• Mitochondria


  • Organelles that break down food and release energy
• Euglena

  • Long cells with green chloroplasts
  • Red eye spots help them find sunlight
  • Obtain energy through photosynthesis like plants
• Reproduction

  A species must be able to reproduce to pass on its genes to the next generation
• Single-celled organism reproduction

  1. Duplicates its DNA

  2. Each daughter cell receives a complete copy of the parent's genes
• Lack of concentration in the classroom is a big problem which can often be mistaken for pupils being uninterested in a lesson or perhaps not getting enough sleep the night before
• There could be another reason for lack of concentration - the air we breathe
• Energy


  A vital part of biology, needed for all processes in our bodies (e.g. movement, keeping warm, chemical reactions)
• Cellular respiration

  The process that takes place continuously in all living cells to produce energy
• Respiration


  An exothermic reaction that releases energy
• Types of respiration

  • Aerobic
  • Anaerobic
• Aerobic respiration


  Takes place when oxygen is present
• Anaerobic respiration


  Occurs when there is no oxygen present
• Anaerobic respiration converts glucose to lactic acid, which requires no oxygen but releases energy
• Anaerobic respiration is less efficient, producing less energy for the same amount of glucose
• Fermentation


  An anaerobic respiration process in plants and yeast cells that converts glucose to ethanol and carbon dioxide, releasing energy
• Aerobic respiration

  Glucose reacts with oxygen to produce carbon dioxide and water, releasing energy
• The symbol equation for aerobic respiration is C6H12O6 + 6O2 -> 6CO2 + 6H2O
• Respiration takes place continuously in all living cells, including in a full classroom
• As carbon dioxide levels increase in a classroom


  It can have a negative impact on brain function and cognitive abilities
• The crucial carbon dioxide level is 1000 parts per million - above this, brain function becomes restricted
• Classrooms often do not have sufficient ventilation to keep carbon dioxide levels below 1000 ppm
• Mechanical ventilation with heat recovery


  A solution that can ensure air is changed regularly to keep carbon dioxide levels down, while recovering heat to avoid drafts
• Keeping carbon dioxide levels down allows sufficient oxygen to reach the brain for effective aerobic respiration and concentration
• Inheritance


  The passing of physical or mental characteristics genetically from parents to offspring
• Aristotle noted that children often look like their parents but why was unclear

  Ancient Greeks
• Aristotle's view


  The man determined the form of the child, the woman provided the material
• Dutch Medics announced that women actually produced eggs like birds


  1600s
• Dane called Niel Stenson re-christened the organs formerly known as female testicles as ovaries


  1600s
• Dutchman discovered sperm using a primitive microscope


  1600s
• For around 150 years there was a battle between the Ovis (egg) and the Spams (sperm) as to which was more important</b>
• Robert Bakewell's breeding of super sheep suggested offspring were a mixture

  1800s