Lesson 14 Natural And Artificial Cloning
- 1. Natural and artificial cloning Aims: Understand how clones of animals occur: Naturally, when cells of an embryo separate Artificially, when the nucleus from an adult body cell is transferred into an empty unfertilised egg cell (B1.4.3) Lesson 14
- 2. Multiple choice 1. Cloning is an example of Sexual reproduction Asexual reproduction Therapy 2. Variations between animal clones are a result of Different genes Environmental factors Different parents
- 3. 3. A embryo is An unborn baby A multicellular organism A zygote 4. What sort of division is used to produce an embryo from a zygote? Mitosis Meiosis Multi cell division
- 4. Twins Humans usually give birth to a single baby. Occasionally, two embryos develop together, each with its own placenta and umbilical cord, resulting in twins. There are two types of twins and they arise in different ways.
- 5. Fraternal and identical twins Ovary Ovary Foetus Foetus Foetus Foetus The ovum is fertilised by one sperm A single ovum is released from the ovary The embryo splits into two identical embryos The zygote divides to form an embryo. Each zygote forms an embryo. Each ovum is fertilised by a different sperm Two ova are released from the ovary at the same time
- 6. Comparing fraternal and identical twins Offspring are not genetically identical to parent or other off spring. Off spring are genetically identical to each other. Parents and offspring are genetically identical . Identical twins Fraternal twins Description
- 7. How did scientists clone dolly the sheep? The empty unfertilised egg cell gains a new nucleus from the adult body cell. The embryo of this cell was then grown for a few days. This embryo was then implanted into a sheep's womb. The new animal was a clone of the animal that donated the nucleus. Artificial cloning Unfertilised egg cell (ovum) Body cell 1. Nucleus is taken out of unfertilised egg cell Unfertilised egg cell (ovum) 2. Nucleus is taken out of body cell 3. Body cell nucleus is placed in empty unfertilised egg cell.
- 8. C2 Cloning
- 9. Natural and artificial cloning in animals. (H) Describe how identical twins are formed. What may cause a woman to release more than one ova at a time? Why is it rare for larger animals to produce clones? Describe how dolly the sheep was cloned. Why do scientists think that more research needs to be done on artificial cloning? List some possible implications of artificial cloning of animals.
- 10. Natural and artificial cloning in animals. (F) Describe how identical twins are formed. Describe how dolly the sheep was cloned. Why do scientists think that more research needs to be done on artificial cloning? List some possible implications of artificial cloning of animals.