高一教案 第821期(2)
发布时间:2021-03-01
2020-2021学年度第27期总第821期
Cloned back to life (P6)
山东省烟台第二中学 孔洁
Activity 1 Lead-in
•What do you know about black-footed ferrets?
Facts about black-footed ferrets
•Black-footed ferrets are one of the most endangered mammals in North America and are the only ferret species native to the continent. Their recovery in the wild signifies the health of the grassland ecosystem which they depend on to survive.
•The current population: approximately 370 in the wild
•What can we do to conserve endangered animals?
Do you think cloning is an effective way to conserve endangered species?
Activity 2 Skimming
1. Can you predict the main idea of the passage based on the title?
2. Read and check your prediction.
It introduces a cloned black-footed ferret, the first successfully cloned endangered animal, which is a breakthrough in animal conservation.
Activity 3 Scanning
Read and answer the following quesitons.
1. Why does the author mention that in the 1900s, they “burrowed throughout the American West”?
The author intends to make a comparison between the population's abundance in the 1900s and now.
2. What contributed to the black-footed ferrets’ population declining?
The disappearance of their main food source, prairie dogs, which were nearly wiped out by poison, plague and habitat loss.
•
3. What’s the negative effect of a lack of genetic diversity?
Without an appropriate amount of genetic diversity, a species often becomes more susceptible to diseases and genetic abnormalities.
4. Why was Willa chosen?
Genetic value
Willa was not one of the seven ancestors. Her genes possess
“three times more unique variations than the living population”.
5. What is the priority of ferret conservation?
Maintaining and increasing the wild population is the priority. Also, preserving their habitat, as it is essential for the recovery of the black-footed ferret species.
Activity 4 Debate
Do you think cloning is an effective way to conserve a species?
Yes
•1. It can increase the population of endangered animals.
•2. It has genetic advantages that enable the species to better withstand the environment.
•3. Animal cloning doesn’t have to involve the entire animal, so it doesn't threaten the animal’s life.
•…
No
•1. Cloning does not address the reasons that many animals become endangered in the first place - namely, hunting and habitat destruction.
•2. Even if cloning could theoretically help in truly desperate situations, current cloning techniques are simply too ineffective to make much of a difference.
•…
Activity 5 Language focus
Paraphrase the following sentences.
•1. Without an appropriate amount of genetic diversity, a species often becomes more susceptible to diseases and genetic abnormalities.
•The lack of genetic diversity increases the chance for the species to get sick and have genetic abnormalities.
•2. But it was a commitment to seeing this species survive that has led to the successful birth of Elizabeth Ann.
•What has led to the successful birth of Elizabeth Ann was people’s wish to see this species survive.
•It was…that: 强调句型,强调主语a commitment to seeing this species survive
•Eg. It was his dedication to this cause that brought great hope to this country.