12-26 23:19:43 浏览次数:341次 栏目:高三英语教案
America’ differences in habitat could lead to different species in birds as well as in plants.
Gregor Mendel Flowers and peas Many characteristics were passed on from one generation to the
next, without influence by the environment. His research gave birth to the science of genetics.
Gote Turesson A wild plant found on the Swedish west coast Found evidence for the existence of
stable varieties within species in nature. He showed that differences between plants of one species
occurred as a result of the environmental conditions in their habitat.
The text can be divided into four parts
Part I Pa. 1-3: Darwin and his research.
Part II Pa. 4-5: Mendel and his experiment.
Part III Pa. 6: Turesson and his study
Part IV Pa. 7: the importance and significance of the research of the three.
Important sentences in the passage
1. It was Darwin’s visit on the Beagle to the Galapagos Isles that gave him the key to his new theory
.
2. Back home, in England, Darwin realized that differences in habitat could lead to different species
in birds as well as in plants.
3. As a result of Darwin and Mendel’s research, scientists of the nineteenth century formed the
belief that that influence of the environment was behind the development of new species.
4. It would take a next generation of scientists to bring the importance of the environment on species
back in view.
Step 4 Writing
Different habitat, different dandelions
As shown in the picture, dandelions take on different appearances in different habitats. The first
picture shows a hot, dry habitat, in which the dandelion grows low, with thin, yellowish flowers and
narrow light green leaves; while the second one shows a wet and cool habitat, in which the
dandelion is taller with rich but bright yellow flowers and broader leaves. So we can reach a
conclusion like this: plants change their appearance and adapt to the new environment if moved from
one habitat to another.
Homework
Make some observations of the plants somewhere in the wild areas as required in the textbook, but
make sure you are in a safe distance. Make notes of your impressions of the plants. For this task,
you can work in groups or pairs in a corporative way, and you must think of ways to describe what
you have seen or done.
Period 6 Grammar
Teaching aims:
1. Review what can be used as the object.
2. Review some important rules about the object.
Teaching important points:
1. Master the v.-ing form and the infinitive used as the object.
2. Master the compound object and “it” used as the formal object.
Teaching difficult point:
How to master the differences between v.-ing form and the infinitive used as object.
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