biology paper 1

• Cells


  • Cafe are the budding Mocks of age afphe
  • Cells can be Prokaryotic or Eukaryotic
  • Abs are made of col
  • stares. All land alt cells are eukaryotic
  • aj kants are sc and sales. Bester are prokaryotic cells
• Plant and Animal Cells

  • Have Similarities and Differences
• Additional structures plant cells have


  • Awal-made of celuisas
  • A gemerentasuole-confeine call p
  • Chloraplats-where photosynthesis happens
• Subcellular structures bacterial cells have


  • Callal
  • Calmand
  • Qutom
  • A single loop of DNA
  • Plasmids-amall rings of extra DNA
• Bacteria don't have a 'true' cucleus
• Estimating the area of a subcellular structure


  1. Treat it like a regular shape

  2. Use the formula length x width
• Cell Organisation


  • Large Micellular Organisms are Made Up of Organ Systems
  • Similar Celle Make Up Tissacs
  • Tians Make Up Organs
  • Organs Make Up Organ Systems
• Enzyme catalysis


  • Substrate binding
  • Transition state facilitation
  • Catalysis
  • Release
• Enzymes have active sites that fit the substrate
• Enzymes need cofactors and coenzymes to work
• Enzymes can be inhibited by competitive or non-competitive inhibitors
• Microscopes


  • Magnify things (make them look bigger)
  • They have lenses that focus light
  • They have a light source
• Magnification


  How many times bigger the image is than the real size
• The resolution of a microscope is the smallest distance between two points that can be distinguished
• You should write down the preparation method and what was observed
• Chromosomes


  • Contain genetic material
  • Coded length of DNA
• Some people are against stem cell research
• Cells can produce identical plants through vegetative propagation
• Cell membranes


  • Control what goes in and out of the cell
  • Made of phospholipids
  • Allow diffusion of small molecules
• Osmosis


  The movement of water molecules from an area of high water concentration to an area of low water concentration
• Root hairs take in minerals and water using active transport
• Active transport is needed to maintain the correct concentrations of substances in the body
• Use Iodine Solution to Test for Starch


  1. Take a small sample of the food

  2. Add a few drops of iodine solution to the sample

  3. If the solution changes colour from brown to blue-black, it indicates the presence of starch
• Use the Sudan III Test to Test for Lipids


  1. Add a few drops of Sudan III solution to the test tube

  2. Shake the tube well

  3. If lipids are present, the solution will turn red
• Air Moves In and Out

  1. The diaphragm moves down, causing air to be drawn into the lungs

  2. Then it moves up, pushing air out of the lungs
• Alveoli


  • They carry out gas exchange
  • Bad air comes to the lungs
  • Oxygen diffuses into the blood
  • Carbon dioxide diffuses out into the air in the alveoli
• The lungs are really well adapted for carrying out gas exchange
• Calculate the Average Breathing Rate


  1. Time how long it takes for 10 breaths

  2. Divide 600 (10 breaths x 60 seconds) by the time taken in seconds

  3. This gives the average breaths per minute
• The Heart


  • It pumps blood around the body
  • It has 4 chambers
  • Deoxygenated blood enters the right side
  • Oxygenated blood leaves the left side
• You Can Calculate the Rate of Blood Flow


  1. Measure the volume of blood that passes through in a given time

  2. Divide the volume by the time to get the rate
• The heart has a pacemaker
• Calculate the Rate of Blood Flow


  1. Measure the volume of blood that passes through in a given time

  2. Divide the volume by the time to get the rate
• Blood Cells


  • Red blood cells carry oxygen
  • White blood cells defend against infection
  • Platelets help blood clot
• Statins Reduce Cholesterol


  1. Statins are drugs that lower cholesterol levels

  2. They reduce the risk of heart disease and strokes
• Artificial Hearts


  • They can pump blood around the body
  • The body may reject them more than a donor heart
  • They can cause blood clots
• Risk Factors for Non-Communicable Diseases


  • Lifestyle factors (smoking, obesity, lack of exercise)
  • Genetic factors (family history)
• Non-communicable diseases can be costly for individuals and society
• Risk factors


  Increase your chance of getting a non-communicable disease
• Some risk factors can directly cause a disease, like cancer
• fen their my hang will be reduced.