7.5

• Genetic engineering

  1. Scientists adding genetic material to, taking genetic material away from, or transferring genetic material between organisms

  2. Gene can be cut out of the DNA of one organism using enzymes and then added into the DNA of a bacterium

  3. The added gene is then copied by the bacterium many times
• Genes are sections of DNA
• The DNA code is very similar in many organisms
• Insulin is a hormone that lowers the concentration of sugar in the blood and is made in an organ called the pancreas
• People with diabetes do not produce enough insulin
• In the past, insulin was taken from the pancreas of pigs (and cows) after they died, but in 1978, human insulin was successfully produced using bacteria by an American company called Genentech
• Genetic engineering (insulin)

  1. They inserted the gene for healthy human insulin into bacteria

  2. The bacteria then produced lots of human insulin

  3. Now widely available as Humulin® (human insulin)
• Genetic engineering or genetic modification is made possible by the similarity in DNA code among organisms
• Cystic fibrosis is a genetic disease that causes thick mucus to be produced in the lungs and gut, making breathing difficult and providing a breeding ground for microorganisms
• One organism can understand the genes of another
• Sufferers of cystic fibrosis tend to get lung infections easily
• Cloning is a method of reproduction that results in genetically identical offspring being produced
• Genetic engineering (cystic fibrosis)

  1. The disease is caused by a faulty gene

  2. Scientists have genetically modified viruses to contain copies of the normal gene, which they hope will be able to be used in a nasal spray to introduce the normal gene into lung cells
• Genetic engineering (cystic fibrosis)

  1. Human eggs (ova) can be taken out of a woman’s body, fertilized, and then put back

  2. Genes could be transferred to cells while the ovum is outside to produce certain characteristics

  3. This could be used to prevent babies from being born with cystic fibrosis

  4. This has not yet been done in the UK as it is illegal to alter the set of genes in ova or zygotes
• Plants have been cloned for a long time
• Cloning


  1. A simple way is 'taking a cutting'

  2. British scientists have developed a method of cloning animals

  3. First began work cloning frogs and then in 1996 the first adult mammal was cloned, Dolly the sheep
• Cloning (Dolly the sheep)


  1. The first successful clone out of 277 attempts

  2. An udder cell was removed from a fully grown sheep

  3. An ovum from another sheep was taken and its nucleus was removed

  4. The nucleus of the udder cell was put into the empty ovum

  5. The whole cell was implanted in a third sheep

  6. Grew into Dolly

  7. Dolly was a clone of the sheep that donated the udder cell
• Organ transplants

  1. Some people with damaged organs can have them replaced

  2. Unfortunately, there are not enough human organs to supply all who need them

  3. Medicines were developed to prevent the immune system rejecting the new organ

  4. Techniques for matching tissue were developed so that the implanted organ matched the rest of the body tissue as closely as possible

  5. Xenotransplantation is the transplanting of cells, tissues, or organs from one species to another

  6. Scientists are working on breeding animals, particularly pigs, to provide organs for transplantation

  7. Parts of pig hearts are used to repair human hearts, but transplanting a whole pig heart into a human has not been successfully done due to the human immune system attacking the pig heart

  8. Genetically modified pigs are being developed to contain human genes
• Cloning (Dolly the sheep)


  1. Dolly grew from the nucleus of the udder cell being put into the empty ovum

  2. The whole cell was implanted in a third sheep

  3. Dolly was genetically identical to the sheep that donated the udder cell
• Genetically modified food

  1. More than 60 plant species have been genetically modified, including commercial crops such as oilseed rape, maize, potatoes, tomatoes, and soya

  2. Plants are genetically engineered to be resistant to diseases, improve their nutritional value, and survive in different conditions such as drought, flood, or frost

  3. Examples include maize, which produces a toxin from a bacterium to kill a major threat insect, and soya, which is tolerant to certain herbicides, reducing the need for multiple herbicide sprays
• • Genetic engineering has many positive uses, including producing cures for diseases and improving food production by reducing the need for chemicals
  • However, genetic engineering may have unknown side effects, and the ethical implications of genetic engineering in embryos are subject to ongoing debate
• Smoking is considered to be one of the most preventable causes of death in the United Kingdom
• Approximately 80,000 people die of smoking-related illnesses every year
• Chemicals in cigarettes


  • Tar
  • Carbon monoxide
  • Hydrogen cyanide
  • Nicotine
• Nicotine


  • Very addictive and makes it hard to give up smoking
• Nicotine causes


  Heart disease by narrowing blood vessels, increasing blood pressure, and making the heart work harder
• Increased blood pressure


  Puts more strain on the blood vessels supplying the heart's muscles with blood
• Effects of chemicals in tobacco

  • Tar damages bronchi and alveoli, builds up in the lungs making it harder to get oxygen into the blood
• Tar can cause


  Uncontrolled growth of cells in the lung resulting in cancer
• Untreated cancer


  Can spread to other parts of the body and be fatal
• Carbon monoxide


  Stops blood carrying oxygen efficiently, puts more strain on the heart, increases the risk of a heart attack
• Carbon monoxide combines with hemoglobin


  Less oxygen can be carried in the blood
• Pregnant woman who smokes

  Does not give as much oxygen to the baby, leading to low birth weight
• Risks for smokers


  • Developing a smoker's cough, bronchitis, or emphysema
• Smoker's cough


  Occurs when cilia are damaged by cigarette smoke, leading to difficulty in removing mucus and dirt from the lungs
• Bronchitis


  Disease caused by bacteria infecting the bronchi, resulting in difficulty in breathing
• Emphysema


  Cells in the alveoli are irritated by cigarette smoke, leading to inflammation, destruction of cells, and difficulty in gas exchange
• Emphysema sufferer


  Needs to take a cylinder of oxygen to help with breathing, as the damage to the lungs cannot be repaired