(8) Learning objectives for this page

• Know and understand that genes can also be transferred to the cells of animals, plants or microorganisms at an early stage in their development so that they develop with desired characteristics.

  • Know that new genes can be transferred to crop plants.

  • Crops that have had their genes modified in this way are called genetically modified crops (GM crops).

  • Examples of genetically modified crops include ones that are resistant to insect attack, viruses, fungi or to herbicides.

    • This is all about increasing the quantity and quality of crops - insert genes into the plant's genome to increase the size and the quality of the grain.

      • Similarly, you can do the same for fruit plants to increase the quality (e.g. taste) and size of fruit.

    • Large quantities of crops are lost to disease and insect attack, so it make economic sense in principle.

    • One practical example is that if you can make a crop resistant to a herbicide that is used to kill weeds - weeds that compete for the soil nutrients, then you can kill the weeds by spraying without damaging the crops.

    • You can produce plants (fruit or grain) that are also resistant to diseases and insect attack to improve crop yields.

    • You can genetically engineer sheep to produce substances like drugs in their milk, which are used to treat certain human diseases.

  • Genetically modified crops generally show increased yields.

• Appreciate concerns about GM crops include the effect on populations of wild flowers and insects, and uncertainty about the effects of eating GM crops on human health.

  • There is considerable public concern about GM crops eg are they harmful, are they as nutritious, are they reducing biodiversity, will they spread and multiply at the expense of native plants - out-compete for nutrients, will they cross-bread with native plants changing the gene pool,

  • GM crops of rice, and other basic grown foods, are seen as an economic way of feeding the growing poor populations of third world countries.

    • The idea behind GM crops is to increase yields and increase nutrition.

    • You can insert genes into crop cells so that they contain particular nutrients, whose deficiency can cause ill-health, or engineer a strain of wheat to contain more protein if meat is scarce.

    • So there are lots of possibilities and lots of controversies - so 'watch this GM space'

• In the context of genetic engineering, be able to explain the role of the scientific community in validating new evidence, including the use of:
  • a) scientific journals - enable new findings on genetic engineering to be communicated to other scientists working in the same areas of science, so ideas and knowledge are widely spread AND other scientists can check whether the research is valid eg do other scientists get the same results? do other scientists draw the same conclusions? do other scientists agree with, and find the theory valid?
  • b) the peer review process - a sort of refereeing system, research papers on genetic engineering are read and checked by people competent to understand the contents of research papers (their peers) - this ensures standards are high in terms of 'good scientific practice'.
  • c) scientific conferences enable scientists to meet and present and discuss their findings on genetic engineering, compare their work, listen to new ideas, get ideas to take back to their own research project. Its also a forum for other scientists to hear about research which isn't necessarily exactly their own specialist field, but broadens their own knowledge of related fields of science e.g. genetic engineering.

Be able to make informed judgements about the social and ethical issues concerning the use of stem cells from embryos in medical research and treatments

Be able to make informed judgements about the economic, social and ethical issues concerning embryo screening.

Be able to demonstrate an understanding of how gene mutations change the DNA base sequence and that mutations can be: