选修九 4.2《Unit 4 Key to exercises in the workbook (II)》PPT课件(新课标人教版-选修9)

First reading 2 Now read the text more carefully and
answer these questions. 1.ቤተ መጻሕፍቲ ባይዱWhy can no other animals but the yucca moth pollinate the yucca?
It’s only the yucca moth which is the right size and shape to pollinate the yucca.
The male wasps try to mate with the orchid flowers because they look like and smell like female wasps.
5. Why do the female wasps visit the orchid flowers? Do they have a role in pollination?
新课标人教版课件系列
《高中英语》
选修(模块）9-4.2
Reading on P.78
Warming up
Discuss the question: What’s the relationship between plants and animals?
Pre-reading 1 Before you read the text, glance quickly
The female wasps visit the orchid flowers to collect the chemical that the male wasps were attracted to earlier. The female wasps do not have a role in pollination since the flowers are dying when they visit them.
flower can be disadvantage for
opened by the the palm only if
lemur.
there are no
Lemur
The lemur has a source of food.
lemurs or other animals present strong enough to open the flowers.
each other for
The moth’s
survival.
caterpillars have
a certain supply
of food
Plant/
Advantages Disadvantages
pollinator
Traveller’s The palm’s There is a
palm
2. Can you guess why the Traveller’s Palm has that name?
The Traveller’s Palm has this name because travellers used to drink its nectar when they were thirsty.
Plant/
Advantages Disadvantages
pollinator
Orchid Wasp
The orchid is certain to be pollinated.
The female wasps collect a chemical from the orchid needed to attract the males to them.
through it and answer these questions. 1. What’s the topic of the text? 2. What three plants are featured? 3. What do the photos show you? 4. What three animal pollinators are featured?
Suggested answers:
The yucca and the yucca moth:
If yucca plants died out, the Yucca moth would also die out as the caterpillars need the yucca seeds for food.
Yucca flowers, a Traveller’s Palm, and an Ophrys orchid. 4. What three animal pollinators are featured?
The yucca moth, the Madagascar black lemur, a certain kind of wasp (the male, not the female wasp).
The Traveller’s palm and the Madagascar black lemur:
If the Traveller’s palm died out, the Madagascar black lemur would not die out as it can find other sources of food.
Check your understanding and complete the table.
Plant/
Advantages Disadvantages
pollinator
Yucca Moth
The yucca is
certain to be pollinated.
They are totally dependent on
1 What’s the topic of the text? Co-evolution.
2 What three plants are featured? The yucca, the Traveller’s Palm, and the Ophrys
orchid. 3 What do the photos show you?
3. What do you think “sweet tooth” means?
If a person or an animal has a “sweet tooth”, they like sweet food very much.
4. Why do the male wasps try to mate with the orchid flowers?
Second reading
3 Now read and think about the advantages and disadvantages of the relationships between the plants and pollinations described in the text.
They are totally dependent on each other for survival.
Discussion
4 Discuss what you think would happen
to the animal pollinators of each of the plants described if these plants died out.
The Ophrys orchid and the wasp:
If the Ophrys orchid died out, the wasp would also died out as the female wasp needs the chemical produced by the orchid to attract the male wasps.