英语高二下人教版新课标选修8 Unit 2第6课时教案（文化背景知识）
I. Reading comprehension:
Hello, Dolly!
British scientists have done something that many people thought was impossible: they created the first clone of an adult mammal. The clone, named Dolly, is a seven-month-old sheep, grown from a cell of an adult female sheep.
What is a clone? A clone is a copy, a genetic copy. Genes are the instructions for life. They tell a cell what to do and how to do it. Genes make each individual plant or animal different and unique. But a clone has the same genes as the original organism.
Cloning is not new. Plants have been cloned for centuries. New plants are often grown from cuttings from another plant. Also, plants like pineapples, strawberries and carnations are sometimes cloned. One benefit of cloning is that we can make many copies of the best and healthiest plants.
It has been much more difficult to clone animals. Frogs have been cloned, but they died as tadpoles, never living long enough to become adult frogs. Mice, sheep and cattle have been cloned from embryos. But Dolly is the first healthy clone of an adult mammal. How did they do it?
