课标人教实验版 高三 Module 9 Unit 4

Reading on P78

Co–Evolution yucca 丝兰

yucca moth

The Traveller’s Palm 棕榈树

The Madagascar black lemur

The Ophrys Orchid 兰花

wasp

Warming up Discuss the question: What’s the relationship between plants and animals?

Pre-reading Before you read the text, glance quickly 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?

1.What’s the topic of the text? 2. What three plants are featured? Co-evolution. The yucca, the Traveller’s Palm, and the Ophrys orchid.

3. What do the photos show you? 4. What three animal pollinators are featured? Yucca flowers, a Traveller’s Palm, and an Ophrys orchid. The yucca moth, the Madagascar black lemur, a certain kind of wasp (the male, not the female wasp).

First reading Now read the text more carefully and answer these questions. 1.Why 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.

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.

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? 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? 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.

Second reading Now read and think about the advantages and disadvantages of the relationships between the plants and pollinations described in the text. Check your understanding and complete the table.

Plant/ pollinator AdvantagesDisadvantages Yucca Moth The yucca is certain to be pollinated. The moth’s caterpillars have a certain supply of food They are totally dependent on each other for survival.

Plant/ pollinator Advantages Disadvantages Traveller’s palm Lemur The palm’s flower can be opened by the lemur. The lemur has a source of food. There is a disadvantage for the palm only if there are no lemurs or other animals present strong enough to open the flowers.

Plant/ pollinator Advantages Disadvantages Orchid Wasp The orchid is certain to be pollinated. They are totally dependent on each other for survival. The female wasps collect a chemical from the orchid needed to attract the males to them.

Discussion Discuss what you think would happen to the animal pollinators of each of the plants described if these plants died out.

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.

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.

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.