1、Unit 2 CloningPeriod 1 warming up and pre-readingTeaching goals:1. Enable the students to know what is cloning.2. Enable the students to know what are natural clones and man-made clones.3. Enable the students to know some basic knowledge about cloning.Teaching important and difficult points:Enable t
2、he students to know what cloning is.Teaching methods:Speaking, answering, thinking.Teaching aids:A blackboard and a computerTeaching proceduresStep 1 Warming up.1. Ask the students to describe what cloning is.2. Show the students the definition of cloning.3. In pairs, look at these pictures and disc
3、uss which ones are natural clones and which ones are man-made. Think about how they differ.Natural clone is one that occurs from the “parent ” in a natural form of cloning without human help. Man-made clone is one that produced through human intervention(介入) Step 2. EnjoyingEnjoy some pictures of na
4、tural cloning examples and man-made cloning examples.Step3. Show the students how a clone is produced by cloning a sheep.1. A female sheep provides an egg cell. The nucleus is removed from the egg cell.2. A second female sheep provides a somatic cell. The nucleus is also taken out. 3. The egg cell f
5、rom sheep A and the nucleus from sheep B are joined together using electricity.4. The combined cell divides and grows into an embryo.5. The embryo is then put into female sheep C. Finally a sheep D is cloned.Step4.Talk about what benefits humans can gain from cloning?Step5.Talk about what problems may arise when humans are cloned?Step6. HomeworkPreview Reading: Cloning; where is it leading us? Do the Comprehending on P12 of the textbook.
