Revision Method Workshop Biology (Group Work) K&S.pptx

Gmos yo

1. REVISION METHOD WORKSHOP (BIOLOGY) -Krishna Sawant and Shivansh Singh IGCSE 2

2. WHAT IS GENETIC MODIFICATION Genetic modification is also called genetic engineering. This process involves moving a gene or genes from one species to another. This is a complicated scientific process which can improve crops and even make bacteria to make medicines like insulin.

3. REASONS FOR GENETICALLY MODIFYING ORGANISMS Produce faster-growing crops or animals Produce plants that are more resistant to pests Produce crops that are drought resistant Produce foods that stay ripe longer Endless Summer Tomato Research: Drug development Commercial reasons Fluorescent fish for pets Increase yield of crop Reduce cost that is passed to consumer Enhance the nutritional value of a food Golden Rice

4. CONTROVERSY OF GENETICALLY MODIFIED ORGANISMS Controversy over GMOs in general : Genetic modification is placing the genes of one species into another unrelated species. Some modifications are created by corporations to make crops resistant to pests or to certain chemicals. Controversy over GM foods: Have they been tested enough to prove they are safe? Could pesticide resistant plants become toxic? Could peanut genes inserted into soybeans cause unexpected allergic reactions?

5. CURRENT USES OF GENETIC ENGINEERING

6. HUMAN INSULIN IN BACTERIA Diabetes is a disorder in which the body's blood glucose levels remain too high because glucose is not effectively removed from the blood. It can be treated by injecting insulin. This hormone can be produced by genetically modified bacteria and has been in use since 1982. The human insulin gene is inserted into bacteria, which then secrete human insulin. The GM insulin is acceptable to people with a range of religious beliefs who may not be allowed to use insulin from cows or pigs. Bacterial cells have been genetically modified to produce substances such as human insulin

7. GENETICALLY MODIFIED CROPS Current genetically modified crops include those that are resistant to insect attack or are herbicide resistant, this produces increased yields. Herbicide-resistant crops allow them to tolerate the herbicide, but the weeds are killed by it, therefore less herbicide is needed.

8. GOLDEN RICE Scientists have added a gene to wild rice that makes it produce beta-carotene. This changes the colour of the wild rice to a golden colour. Beta carotene is needed by humans in order to make vitamin A which is essential for good vision. The advantage of golden rice is that it can be used in areas where vitamin A deficiency is common, so it can help prevent blindness. In many countries, golden rice is not being grown commercially over fears associated with genetically modified crops.

9. PEST RESISTANCE The bacterium, Bacillus thuringiensis, produces a toxin that kills caterpillars and other insect larvae. The toxin has been in use for some years as an insecticide. The gene for the toxin has been successfully introduced into some plant species using a bacterial vector. The plants produce the toxin and show increased resistance to attack by insect larvae. The gene is also passed on to the plant’s offspring. Unfortunately there are signs that insects are developing immunity to the toxin. Most American GM maize, apart from its herbicide-resistant gene, also carries a pesticide gene, which reduces the damage caused by a stem-boring larva of a moth

10. OTHER USES Inadequate intake of iron is one of the major dietary deficiencies. An enzyme in some plant roots enables them to extract more iron from the soil. The gene for this enzyme can be transferred to plants, such as rice, enabling them to extract iron from iron-deficient soils. Some acid soils contain aluminium levels that reduce maize yields by up to 8%. About 40% of soils in tropical and subtropical regions have this problem. A gene introduced into maize produces citrate, which binds the aluminium in the soil and releases phosphate ions. As a result of irrigation, much agricultural land has become salty and unproductive. Transferring a gene for salt tolerance from mangrove plants to crop plants could bring these regions back into production. If the gene, or genes, for nitrogen fixation from bacteria or leguminous plants could be introduced to cereal crops, yields could be increased without the need to add fertilisers. for drought resistance would make arid areas available for growing crops. Genes coding for human vaccines have been introduced into plants.

11. PROS AND CONS OF GMO FOOD Pros Higher crop yields Reduced need for herbicides and pesticides Improved food quality Increased nutritional value Cons Possible allergies Unpredicted changes to the ecosystem Chance of new diseases developing

12. ETHICAL ISSUES There are ethical issues involved in genetic modification, as well as concerns about the possible health risks of genetically modified food. For example, a genetically modified food might contain a substance that causes an allergic reaction in some people, or higher levels of a toxin naturally found in the food. Others think it is ethically wrong to create new life forms or to move genes between different species.

13. PROCESS TO MAKE GENETICALLY MODIFIED ORGANISMS The first GMOs were bacteria in the early 1970s. Most basic modifications are designed and prepared using bacteria (usually E.Coli) and then transferred to the target organisms.

14. SELECTIVE BREEDING

15. WHAT IS SELECTIVE BREEDING Selective breeding or artificial selection is when humans breed plants and animals for particular genetic characteristics . Humans have bred food crops from wild plants and domesticated animals for thousands of years.

16. REASONS FOR SELECTIVE BREEDING Improve food production Better able to fight off pests More fit and stronger animals Cows that give more milk Chickens that lay bigger eggs Selective Breeding – Plants and Animals Animal Husbandry – Animals only Typically for farming and agriculture

17. PROCESS OF SELECTIVE BREEDING Decide which characteristics are important Choose parents that show these characteristics Select the best offspring from parents to breed the next generation Repeat the process continuously Human controlled Natural Selection/Evolution

18. CONTROVERSIES OF SELECTIVE BREEDING Animal Rights: Should animals have the right to select their own breeding partners? Unnatural It doesn’t occur in nature, does that make it wrong? Benefits to humanity Better/more plentiful food. Service animals Humans have been using selective breeding for thousands of years already.