Biology 1 set pieces

• Explain the process of mitosis and the cell cycle

  • increase in number of mitochondria and ribosomes

  • genetic material (chromosome) are doubled

  • one set of chromosomes pulled to each end of cell

  • cytoplasm and cell membrane divide to form two genetically identical daughter cells
• What are the adaptations of organs for diffusion

  • large surface area

  • membrane is thin to provide short diffusion pathway

  • efficient blood supply

  • well ventilated
• What is the role of bile in digestion

  • bile is made by the liver and stored in the gall bladder

  • it is alkaline to neutralise stomach acid

  • it emulsifies fat to form small droplets increasing the surface area for lipase to act.
• Where are the digestive enzymes produced?

  Carbohydrase: salivary glands, pancreas and small intestine

  Protease: stomach, pancreas and small intestine

  Lipase: pancreas and small intestine
• What are the substrates of the digestive enzymes?

  Carbohydrase: carbohydrates

  Protease: protein

  Lipase: fats and oils
• What are the products of the digestive enzymes?

  Carbohydrase: simple sugars

  Protease: amino acids

  Lipase: fatty acids and glycerol
• Describe the effects of coronary heart disease

  • layers of fatty material build up in the coronary arteries narrowing them

  • this reduces blood flow through the coronary arteries resulting in lack of oxygen for the heart muscle
• What can be used for coronary heart disease


  Stents: used to keep the coronary arteries open

  Statins: widely used to reduce blood cholesterol levels which slows down the rate of fatty material deposit
• What can a faulty heart valve be treated with?

  Mechanical and biological heart valves otherwise can lead to leaks that cause heart failure, stroke, blood clots, or death due to cardiac arrest
• The process of vaccination 


  A vaccination involves introducing small quantities of dead or inactive forms of a pathogen into the body to stimulate the white blood cells to produce antibodies.

  If the same pathogen re-enters the body the white blood cells respond quickly to produce the correct antibodies preventing infection
• What are drugs tested for ?

  Toxicity, dose, efficacy
• Describe the process of drug testing

  Pre-clinical trials: done in a laboratory using cells, tissues, and live animals.

  Clinical trials: used on healthy volunteers and patients

  • very low doses of the drug given at the start of the clinical trials

  • if the drug is found to be safe, further clinical trials are carried out to find the optimum dose for the drug.

  • in double blind trials some patients are given a placebo

  • finally results are peer reviewed to check for bias
• How are monoclonal antibodones produced?

  • are produced by stimulating mouse lymphocytes to make a particular antibody

  • the lymphocytes are combined with a fast dividing tumour cell to make a cell called a hybridoma cell

  • single hybridoma cells are cloned to produce many identical cells that all produce the same antibody

  • a large amount of the antibody can be collected and purified
• What does OGRE stand for? 


  O xygen

  G lucose

  R espiration

  E nergy
• What happens when there isn’t enough oxygen being transported around the body? 


  If Insufficient oxygen is supplied anaerobic respiration takes place in muscles.

  This causes a build up of lactic acid and creates oxygen debt.During long periods of vigorous activity muscles become fatigued and stop contracting efficiently.