2Know: Want to know: Learnt: CloningKnow:Want to know:Learnt:
3Clone Genetic Modification Nuclear Transfer Inheritance KeywordMeaningCloneChanging the genetic characteristics of an organism by manipulating genes and introducing them into DNA.GeneticModificationIn this technique, the nucleus from a body cell of the adult is removed and implanted into an egg cell that has had the nucleus removed.Nuclear TransferA genetic copy of another single organism, or group of cellsInheritanceA term used to describe the passing of genes from parents to offspring
41. InheritanceA term used to describe the passing of genes from parents to offspring.
52. Genetic ModificationChanging the genetic characteristics of an organism by manipulating genes and introducing them into DNA.
6A genetic copy of another single organism, or group of cells 3. CloneA genetic copy of another single organism, or group of cells
7Most common method of artificial cloning. 4. Nuclear TransferMost common method of artificial cloning.In this technique, the nucleus from a body cell of the adult is removed and implanted into an egg cell that has had the nucleus removed.
8Boardworks GCSE Science: Biology Cloning Cloning a single adult animal, especially a mammal, is very complicated.The most famous animal clone is Dolly the sheep, who was born on 5 July 1996.Dolly was not the first animal clone, but the first mammal to be cloned from an adult cell.Photo credit: Roslin Institute
9Cloning how is it done? Hints Every cell in an organism contains all the genetic information needed to make an organism.
10What is nuclear transfer? Boardworks GCSE Science: BiologyCloningDolly was created using a technique called nuclear transfer.In this technique, the nucleus (i.e. DNA) from a body cell of the adult is removed.This nucleus is then inserted into an egg cell that has had its own nucleus removed.Photo credit: Roslin InstituteThe egg cell is then made to divide and develop like a normal fertilized egg. The important difference is that it only contains the DNA from one, rather than two, animals.
11Boardworks GCSE Science: Biology Cloning Teacher notesThis interactive experiment illustrates how Dolly the sheep was created by nuclear transfer.Some interesting facts that might be worth pointing out:Dolly was born on 5 July She died in 2003, aged six and a half, after developing progressive lung disease – sheep can normally live to 11 or 12 years of ageIt took 277 attempts to successfully create DollyThree ewes were involved in creating Dolly: a six-year-old Finn Dorset ewe whose DNA was cloned, a Poll Dorset ewe who donated the egg cell, and a Scottish Blackface ewe who acted as the surrogate motherDolly was not the first cloned animal – she was the first mammal to be cloned from an adult cellNuclear transfer was first used in 1952 to study the development of frogs. In the 1980s, it was used to clone cattle and sheep using cells taken from early embryos.
12Task Describe the steps of cloning using diagrams. To help you have been given key words for each step:Adult cellNutrientsUnfertilised egg cellNucleus RemovedFusedSurrogateExtension- Write down a list of possible applications of cloning and the risks associated with it.
14Cloning has Many UsesCould help with the shortage of organs for transplants.Study of animal clones could lead to greater understanding of the development of the embryo and of ageing.Preserve endangered species.
15Boardworks GCSE Science: Biology Cloning Teacher notesThis headlines activity can be used to explore media reports about cloning. Students could get into groups and identify bias in the headlines. They could then explore the reasons for the bias and perhaps predict what type of newspaper might run headlines like these. There are no correct answers for this activity.
16Issues Surrounding Cloning Cloning mammals leads to a ‘reduced gene pool’- this means there are fewer different alleles in a population.If populations are all closely related and a new disease appears, they could all be wiped out-because there may be no allele in the population giving resistance to the disease.
17Issues Surrounding Cloning... Cloned mammals mightn’t live as long- Dolly the sheep only lived for 6 yearsShe was put down because she had lung disease and she also had arthritis, these diseases were more usual in older sheep.Dolly was cloned from an older sheep, so its been suggested her ‘true age’ may have been older.But its possible she was just unlucky- and that her illnesses weren’t linked to her being a clone.
18Issues Surrounding Cloning... There are other risks and problems associated with cloningThe cloning process often fails. It took hundreds of attempts to clone Dolly.Clones are often born with genetic defects.Cloned mammals immune systems are sometimes unhealthy- so they suffer from more disease.
19Task You will work in pairs to do this. You need to prepare a 30 second argument for either for or against cloning.This needs to be written in your groupOne person will do ‘for’ the other ‘against’.
21Quick QuestionsIn terms of cells what do specialised and differentiation mean?Name one type of specialised cell and how it is adapted to do its job?
22stem cells can differentiate into any type of cell
231. In terms of cells what do specialised and differentiation mean? Specialised – Cells that have special characteristics to allow them to do their job. Differentiation – In cells, the process whereby new cells develop special characteristics to allow them to do their job.
242. Name one type of specialised cell Red Blood Cell - No nucleus, large surface area.Sperm Cell - Pointy head, tail, enzymes in the cytoplasm.Root hair cell - Large surface area, thin membrane.
25Boardworks GCSE Additional Science: Biology Growth and Development What are stem cells?The first cells are stem cells. These are unspecialized cells capable of developing into many different types of cell.Stem cells found in embryos are called embryonic stem cells and develop into all the different types of cell in the body.Photo credit: Steve Gschmeissner / Science Photo LibraryColoured scanning electron micrograph (SEM) of groups of embryonic stem cells (ESCs). ESCs are pluripotent, that is they are able to differentiate into any cell type. The type of cell they mature into depends upon the biochemical signals received by the immature cells. This ability makes ESCs a potential source of cells to repair damaged tissue in diseases such as Parkinson’s and insulin-dependent diabetes. However, research using ESCs is controversial as it requires the destruction of an embryo. Magnification: x3000 when printed at 10 centimetres wide.If stem cells continued to divide as they were, humans would end up as a large jelly-like blob!
26Boardworks GCSE Additional Science: Biology Growth and Development When the embryo contains about 500 cells, the cells stop being the same and they stop getting smaller with each division. They start to differentiate into different types of cell.stem cellstem celltissue cell
27Boardworks GCSE Additional Science: Biology Growth and Development Tissue cells continue to divide and differentiate, each time becoming more and more specialized.stem celltissue cellsSome will become nerve cells, others will become blood cells, muscle cells, bone cells, etc.nerve cellscardiac musclecellsred blood cells